B11504973.Pdf

Home , Ecological engineering, Engineering studies

http://www.nap.edu/catalog/4919.html We ship printed books within 1 business day; personal PDFs are available immediately.

Engineering Within Ecological Constraints

Peter Schulze, Editor; National Academy of Engineering

ISBN: 0-309-59647-5, 224 pages, 6 x 9, (1996)

This PDF is available from the National Academies Press at: http://www.nap.edu/catalog/4919.html

Visit the National Academies Press online, the authoritative source for all books from the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council: • Download hundreds of free books in PDF • Read thousands of books online for free • Explore our innovative research tools – try the “Research Dashboard” now! • Sign up to be notified when new books are published • Purchase printed books and selected PDF files

Thank you for downloading this PDF. If you have comments, questions or just want more information about the books published by the National Academies Press, you may contact our customer service department toll- free at 888-624-8373, visit us online, or send an email to [email protected].

This book plus thousands more are available at http://www.nap.edu.

Copyright © National Academy of Sciences. All rights reserved. Unless otherwise indicated, all materials in this PDF File are copyrighted by the National Academy of Sciences. Distribution, posting, or copying is strictly prohibited without written permission of the National Academies Press. Request reprint permission for this book.

Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html i e h t be

ion. om r ibut f r t cannot r at not o f EngineeringEngineeringEngineering WithinWithinWithin however, version ng,

i t paper book, at ive EcologicalEcologicalEcological ConstraintsConstraintsConstraints at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f Edited by Peter C. Schulze peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e

h NATIONAL ACADEMY OF ENGINEERING heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, NATIONAL ACADEMY PRESS a bout A ret original t Washington, D.C. 1996

ion.

om NATIONAL ACADEMY PRESS 2101 Constitution Avenue, NW Washington, DC 20418 r ibut f r t cannot The National Academy of Engineering was established in 1964, under the charter of the r at not National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous o

f in its administration and in the selection of its members, sharing with the National Academy of Sci- ences the responsibility for advising the federal government. The National Academy of Engineering however, also sponsors engineering programs aimed at meeting national needs, encourages education and version ng,

i research, and recognizes the superior achievements of engineers. Dr. Harold Liebowitz is president t paper book, at ive of the National Academy of Engineering. at

rm This volume has been reviewed by a group other than the authors according to procedures o approved by a National Academy of Engineering report review process. The interpretations and con- riginal horit ic f clusions expressed in the papers are those of the authors and are not presented as the views of the o

e council, officers, or staff of the National Academy of Engineering. h t he aut Funding for the activity that led to this publication was provided by the W. M. Keck Founda- t

om tion, the Andrew W. Mellon Foundation, and the National Academy of Engineering Technology r as ing-specif t Agenda Program. ion ed f Library of Congress Cataloging-in-Publication Data

peset Engineering within ecological constraints / edited by Peter C. Schulze. y p. cm.

publicat "National Academy of Engineering." her t iles creat is Includes bibliographical references and index. h t L f

M of

ISBN 0-309-05198-3 (alk. paper) and ot X 1. Ecological engineering. I. Schulze, Peter C. II. National Academy of Engineering. om yles, r f GE350.E54 1996 st version 628—dc20 95-47174 CIP print posed

use t Washington, D.C. This book is printed on recycled paper. breaks,

ease Printed in the United States of America l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not PREFACE o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Advances in engineering and technology have historically been crucial to t he aut t

solving important societal problems, including those that result from the om r as ing-specif

t environmental impacts of humans. This pattern will undoubtedly continue into ion ed f the future. Unfortunately, however, the application of some innovations has had peset

y undesirable, sometimes unanticipated, environmental consequences. Therefore,

publicat a primary challenge for the future is to maximize the benefits of technological her t iles creat is

h innovation and use while minimizing undesirable environmental effects. t L f

M of One response to this challenge is the recent efforts in business and industry

and ot X that emphasize preventing environmental damage, a practice based on industrial om yles, r

f ecology. Like traditional ecology, which is the study of natural and managed st version ecosystems, industrial ecology is the study of industrial systems and their

print relationships to natural and managed ecosystems. The foundation of industrial posed e h

heading ecology is a systems approach to environmental design and management based

recom on an understanding of the flows of materials and energy in industrial and use t consumer activities, the effects of these flows on the environment, and the breaks, ease l been influences of economic, political, regulatory, and social factors on the flow, use, P and transformation of resources. These efforts have made substantial progress word has ed.

hs, in reducing pollution and the consumption of raw materials per unit of production. However, inefficiencies are only part of the problem. insert Gains in efficiency can be overshadowed by concurrent increases in the ally

line lengt scale of production that result from population growth or increased per capita original work

e consumption. For example, efficiency improvements in fishing technology have h t led to overfishing and the collapse of several fisheries. Fishing quotas designed to address this problem ideally are based on economic theory and on ecological he original; ion of t at o data ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r and reasoning. In fisheries as in other areas of economic activity, averting ibut f r t cannot problems of overuse will require that insights from ecology, engineering, r at not

o economics, and other fields be better integrated in devising technological and f policy solutions.

however, The papers in this volume are the products of a National Academy of version ng,

t Engineering (NAE) meeting intended to take a small step toward promoting the paper book, at ive necessary multidisciplinary approach. at rm o They were contributed by engineers, ecologists, and social scientists. They riginal horit ic f

o provide a variety of perspectives on the challenges faced in efforts to engineer e h within ecological constraints. We hope these papers will contribute to efforts to t he aut t

om find paths toward sustainability and will stimulate further cross-disciplinary r as ing-specif t interaction. ion ed f This volume originates from an April 1994 meeting we chaired based on a peset y concept originated by Peter Schulze. Both the publication and the meeting are publicat

her t components of an ongoing NAE initiative exploring issues of technology and iles creat is h t

L f the environment. We are indebted to the authors for their excellent

M of

and ot contributions, to a group of external reviewers of those contributions, and to an X editorial team composed of Peter Schulze, Dale Langford, Jessica Blake, and om yles, r f Penny Gibbs. On behalf of Peter Schulze, thanks also go to Austin College for st version supporting his work on this volume. In addition, we thank Deanna Richards, print posed

e who heads up the NAE's technology and the environment effort, and Bruce h heading Guile, who directs the NAE Program Office, for excellent advice and assistance recom

use t throughout the project. Special appreciation also goes to the Andrew W. Mellon Foundation for breaks, ease l been

P supporting this project and related elements of the NAE's Technology and

word

has Environment Program. Finally, we would like to acknowledge the leadership at ed.

hs, the NAE for the foresight to initiate and sustain the NAE's program that

insert continues to play a catalytic role in examining the intimate connection between

ally technology and the environment. line lengt original work e

h ROBERT A. FROSCH t

SENIOR RESEARCH FELLOW, CSIA he original; ion of

t HARVARD UNIVERSITY at o PAUL G. RISSER ue t r have been accident y t

a PRESIDENT represent m are

l MIAMI UNIVERSITY OF OHIO a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not CONTENTS o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

Overview and Perspectives 1 om r as ing-specif

t Peter C. Schulze, Robert A. Frosch, and Paul G. Risser ion ed f peset

y Perspectives on Ecology and Engineering

publicat Determining the Balance Between Technological and Ecosystem 13 her t iles creat is

h Services t L f

M of John Cairns, Jr.

and ot X Engineering Resilience versus Ecological Resilience 31 om yles, r

f C. S. Holling st version A Scalar Approach to Ecological Constraints 45

print Bryan G. Norton posed e h

heading A Perspective on the Relationship Between Engineering and Ecol- 65

recom ogy use t Robert Herman breaks, ease l been Designing Sustainable Ecological Economic Systems 79 P Robert Costanza word has ed.

hs, Ecological Integrity and Ecological Health Are Not the Same 97 James R. Karr insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Ecological Engineering: A New Paradigm for Engineers and Ecol- 111 ibut f r t cannot ogists r at not

o William J. Mitsch f Why Aren't All Engineers Ecologists? 129

however, Albert H. Wurth, Jr. version ng,

i t paper book, at ive Case Studies at rm o Engineering for Development in Environmentally Sensitive Areas: 141 riginal horit ic f

o Oil Operations in a Rain Forest e h June Lindstedt-Siva, Lou C. Soileau IV, Dilworth W. Chamber- t he aut t

om lain, and Martin L. Wouch r as ing-specif t Lessons in Water Resource and Ecosystem Regulation from 163 ion ed f Florida's Everglades and California's Bay/Delta Estuary peset y John R. Wodraska and Peter E. von Haam publicat

her t Engineering Studies Based on Ecological Criteria 177 iles creat is h t

L f Hsieh Wen Shen

M of

and ot "Do No Harm": A New Philosophy for Reconciling Engineering 187 X and Ecology om yles, r f David J. Schaeffer st version print posed

e Biographical Data 197 h heading recom

use t Index 205 breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not Engineering Within Ecological Constraints o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not OVERVIEW AND PERSPECTIVES o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Peter C. Schulze, Robert A. Frosch, t he aut t

and Paul G. Risser om r as ing-specif t The expectations placed on engineers shift with the cultural evolution of ion ed f the societies in which they practice. An important shift has occurred with the peset y growth of human impacts on the planet (Kates et al., 1990; Vitousek et al.,

publicat 1986). When the cumulative impact of humans was small, the environmental her t iles creat is

h implications of engineering designs were of less concern. Now that the impact t L f

M of

of humans has reached a global scale, there is growing concern about the and ot X environmental implications of engineering designs. A new set of constraints has om yles, r f become important to engineers—ecological constraints. st version Engineers are accustomed to contending with a variety of design print posed constraints, from the most rigid thermodynamic laws to budgetary constraints to e h

heading issues of social justice. Ecological constraints add one more set of

recom considerations to the list. Engineering designs are now expected to result in use t products or management plans whose use or implementation will not endanger breaks, ease l been important ecological conditions and processes. This would be a tall order if the P

word requirements in particular instances were precisely known. It is made all the has ed.

hs, more challenging by our only partial understanding of the set of important

insert ecological conditions and processes, and what those conditions and processes require to persist. ally

line lengt One conclusion seems clear. Engineers and ecologists will need to work original work e

h together more often than they have in the past. Progress in both engineering t design and ecological understanding will be necessary if humans hope to keep

he original; (or bring) their impacts within the limits imposed by the desire for ion of t at o "sustainability."1 Ecologists and other environmental scientists need to

ue t collaborate with engineers to describe the requirements of important ecological r have been accident y t

a conditions and processes in terms that can be incorporated into engineering represent m are

l design considerations, and continue a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r to work together to develop suitable engineering plans. Engineers and ibut f r t cannot ecologists certainly can not solve these problems alone, but they do have r at not

o important responsibilities in efforts to keep human environmental impacts f within acceptable bounds.

however, With the exception of selected subdisciplines (Mitsch, in this volume), version ng,

t there is so little dialog between engineers and ecologists that it is hard to know paper book, at ive where to start. What would it mean to engineer within ecological constraints? at rm o What are the ecological constraints? Which constraints are most important? Can riginal horit ic f

o some be ignored? How would one distinguish satisfactory and unsatisfactory e h designs? What does it mean to keep human environmental impacts within t he aut t "acceptable" limits? Four related topics arise frequently during discussion of om r as ing-specif t these broad questions: problem definition, uncertainty, lessons from ion ed f environmental control efforts, and the difficulty of finding short-term solutions peset y that do not aggravate long-term problems. We summarize key themes regarding publicat

her t these four issues below. iles creat is h t L f

M of

and ot

X PROBLEM DEFINITION om yles, r f "Everything should be made as simple as possible, but no simpler." st version attributed to Albert Einstein print posed

e A plan is not likely to be successful if the problem that it is intended to h heading solve is not accurately defined. Whether ecological constraints are met will recom

use t depend upon whether the definition of the problem included those constraints.

breaks, Moreover, when substantial consequences of a project, product, or management ease l been

P plan are not appreciated at the design stage, costly problems may arise later. For

word

has example, almost as soon as the Kissimmee River channelization project was ed. hs, completed, the severe ecological consequences became apparent and much

insert more expensive work was begun to reverse the damage (Shen, in this volume;

ally Wodraska and yon Haam, in this volume). Other examples could be cited, line lengt

original work including the impacts of dams and forestry practices upon salmon and other e h

t fish, the tendency of pesticides to kill a pest's natural predators and lead to

pesticide-resistant pests, transportation of exotic species by ships and airplanes, he original;

ion of impacts of chlorofluorocarbons (CFC) on stratospheric ozone, and even the t at o impact of carbon dioxide emissions on the global atmosphere. This is not to ue t r have been accident suggest that the activities that led to these problems should not have occurred, y t a merely that had these consequences been appreciated and taken into represent m are

l consideration from the outset, it might have been possible to reduce or eliminate a

errors impacts through design or management modifications.

As the problem-definition stage of engineering efforts continues to expand

age breaks in response to environmental concerns, and as our dependence on ecosystem P is new digit

h "services" becomes better understood (Cairns, in this volume), these sorts of pographic y iles. T t

f problems should become less frequent. To this end, several general criteria and e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r guidelines have been offered. Schaeffer (in this volume) suggests that engineers ibut f r t cannot adopt the medical oath to "do no harm," in this case to the environment. Norton r at not

o (in this volume) suggests that engineers adopt the Pareto welfare criterion of f economics, in which case an engineering design would be considered

however, satisfactory if its effects were positive for some individuals and neutral for all version ng,

t others. Holling (1992) argues that efforts to identify ecological constraints may paper book, at ive benefit from a focus in which the environment and its many components at rm o (including humans) are systematically viewed as a hierarchy of systems within riginal horit ic f

o systems. e h Daly and his colleagues (Costanza et al., 1991; Daly, 1990) have suggested t he aut t

om acceptable boundaries for human environmental impacts. Rates of extraction of r as ing-specif t renewable resources should not exceed regeneration rates. Rates of waste ion ed f emission should not exceed the assimilative capacity of the environment.2 Rates peset y of extraction of nonrenewable resources should not exceed the rates at which publicat

her t substitutes are found and developed. These guidelines imply a variety of long- iles creat is h

t term performance standards. For example: pumping from aquifers should not L f

M of

and ot exceed recharge rates; pollutant concentrations should not increase; soil depth X should not decline; harvesting should not cause reductions in population sizes. om yles, r f These guidelines can be useful for identifying unsatisfactory circumstances, but st version it remains to be seen whether they will be elaborated in ways that will make print posed

e them directly useful to engineers struggling to satisfy particular ecological h heading constraints in the context of particular engineering problems. recom

use t Available evidence suggests that when ecological constraints are clearly defined, engineers can develop designs or management plans with the potential breaks, ease l been

P for meeting them. Shen (in this volume) describes two such examples. On the

word

has Niobrara River the challenge was to release water from a dam such that the ed.

hs, downstream reaches of the river would maintain the broad shallow morphology

insert that is required by migrating whooping cranes. In south Florida the challenge

ally was to restore the Kissimmee River such that flood waters would inundate the line lengt floodplain frequently and return to the river channel slowly. In both cases original work e h

t seemingly satisfactory water management plans were developed. Lindstedt-Siva et al. (in this volume) describe another example from ARCO's experience of he original;

ion of exploring for oil in tropical rain forests. Roads built into remote rain forest t at o regions facilitate human immigration and subsequent forest destruction. ue t r have been accident Lindstedt-Siva and her colleagues were determined to explore for oil without y t a building roads. They took their lead from offshore exploration operations, and represent m are

l used helicopters rather than trucks to move equipment. a These examples suggest potential for fruitful collaboration between errors ecologists and engineers. In all three examples, recognition of important

age breaks ecological processes led to the identification of key ecological constraints, and P is new digit

h engineers used those constraints to develop designs that appeared capable of pographic y iles. T t

f satisfying them. Plans for the proposed dam on the Niobrara River were e ile: ng i f canceled because of budgetary constraints, and it is too soon to assess the t F

D success of the other designs. In addition, satisfaction of particular ecological P peset and som

is constraints is not necessarily y h t

ined, a bout A ret original t

ion. om

r the same as satisfaction of all important ecological constraints. Nevertheless, ibut f r t cannot these examples are encouraging. r at not

o Because natural systems are complex, it will not always be easy to identify f key ecological constraints. The examples discussed by Shen and Lindstedt-Siva

however, et al. are relatively simple. In other situations the challenge for designers will be version ng,

t greater, either because the ecological constraints are poorly understood, or paper book, at ive because the connections between design options and ecological processes are at rm o indirect. Nevertheless, past efforts to identify key variables in ecological riginal horit ic f

o systems give some cause for optimism. For instance, the condition of a e h grassland can be predicted from five parameters: species composition, primary t he aut t productivity, species diversity, organic material content of the soil, and nitrogen om r as ing-specif t content of the plants (Risser, 1995). Likewise, the condition of river ecosystems ion ed f can be assessed on the basis of a relatively small set of variables (Karr, in this peset y volume). Once such key variables are identified, studies can begin to examine publicat

her t the types and magnitudes of impacts that environments can absorb without iles creat is h

t being unacceptably altered. L f

M of

and ot Other situations are even more complex. What are the ecological X implications of the design of, for example, a radio? The answer to this question om yles, r f depends on a variety of factors, such as the methods of raw material acquisition, st version the ecological effects of manufacturing wastes, and the way the radios will be print posed

e discarded (Allenby, 1994). When the ecological implications of an engineering h heading design are obscure, it may be most productive to adopt the general approach of recom

use t ''life-cycle analysis'' or "design for environment" in which there is a conscious effort to consider systematically the environmental implications of all aspects of breaks, ease l been

P engineering designs (Allenby and Richards, 1994). Such efforts may be assisted

word

has by Holling's systems perspective and by an identity recently suggested by ed.

hs, Herman Daly (personal communication):

insert A = (B)(C)(D)(E)

ally where: line lengt A = economic services gained/environmental services sacrificed original work e h

t B = economic services gained/economic stock consumed C = economic stock consumed/environmental throughput he original;

ion of D = environmental throughput/environmental stock exploited t at o E = environmental stock exploited/environmental services sacrificed ue t r have been accident The above examples suggest that when specific constraints are identified y t a and agreed on, suitable designs or management plans can be developed. The represent m are

l challenge for engineers and ecologists is to work together to identify key a constraints and develop plans that satisfy those considerations. In many cases it errors will also be necessary to work together to convince others that the desirable

age breaks environmental properties of those resulting designs warrant the necessary P is new digit

h investment (Wurth, in this volume). pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r UNCERTAINTY ibut f r t cannot "And then what?" r at not o f Hardin (1993:16)

however, Because ecosystems are complex, the environmental consequences of version ng,

i human activities are uncertain (Brooks, 1986; Costanza, 1993; Holling, 1993; t paper book, at ive Ludwig et al., 1993). Thus, uncertainties are an important consideration in at rm

o engineering designs and management plans. It can be useful to distinguish three riginal horit ic f types of uncertainty. "Risks" refer to situations where probabilities may be o e

h ascribed to various potential consequences. "Unknowns" refer to situations t he aut t where the range of possible consequences is thought to be reasonably well om r as ing-specif t understood, but the probabilities of the various consequences are unknown. ion ed f "Unknown unknowns'' are phenomena that one is not even aware one fails to peset y expect or understand.

publicat Even though new technologies are often environmentally preferable to her t iles creat is

h those they replace, their large-scale adoption often results in unanticipated t L f 3 M of

undesirable environmental impacts (Gray, 1989). Hindsight suggests there is and ot X room for improvement in our ability to anticipate these impacts. Myers (1995) om yles, r f notes that neither global warming nor acid rain were major concerns at the 1972 st version United Nations conference on the environment in Stockholm, even though print posed Arrhenius had warned of global warming 100 years earlier and biologists were e h

heading aware that massive quantities of sulfur dioxide and nitrous oxides were being

recom emitted into the atmosphere. Perhaps some unknowns would be better described use t as unappreciated knowns or ignored knowns. Whole cadres of environmental breaks, ease l been scientists, policy analysts, and others work on risk assessment, but few are P

word studying approaches to anticipating that Which would otherwise come as a has ed.

hs, surprise.

insert Differences in approaches to uncertainty have major implications for environmental policy (Costanza, 1993). Approaches that focus on risks use ally

line lengt quantitative models in attempts to identify most likely scenarios, and then use original work e

h the results as the basis of policy recommendations (Committee on Science, t Engineering, and Public Policy, 1992; Nordhaus, 1992). An alternative

he original; approach, focused on unknowns, attempts to identify the policy option that ion of t at o minimizes the likelihood of a catastrophic outcome. This approach, which is

ue t embodied in the precautionary principle, does not attempt to ascribe r have been accident y t

a probabilities to alternative possible outcomes (Cameron and Abouchar, 1991; represent m are

l Costanza, 1989, in this volume; Daily et al., 1991). a At the extremes neither approach is perfect. Policies based on a most likely errors scenario will be unfortunate, if not catastrophic, if the eventual outcome is not

age breaks the one that was deemed most likely. Conversely, reliance on the precautionary P is new digit principle begs the question, "How much precaution?" Environmental impacts h pographic y iles. T t are but one of many important consequences of new technologies. An excess of

f e ile:

ng precaution could reduce innovation and its associated benefits. In addition, even i f t F

D though a new technology may have unanticipated effects, its aggregate P

peset environmental impacts may be preferable to those of the older technology that it and som is y h t replaces.

ined, a bout A ret original t

ion. om

r Finally, there is an issue of opportunity costs. An excess of precaution ibut f r t cannot directed toward one concern may reduce the potential effort available for r at not

o investment in other concerns. Thus, opportunities to address ecological f constraints could be harmed by being too cautious. Good policy requires

however, explicit consideration of risks, unknowns, and unknown unknowns. version ng,

t Approaches to dealing with uncertainty are particularly relevant to paper book, at ive discussions among engineers and ecologists since both casual experience and at rm o the literature suggest that members of these two communities tend to have riginal horit ic f

o different expectations regarding the future consequences of human e h environmental impacts (Nordhaus, 1994; Schaeffer, in this volume). t he aut t

om Differences in expectations may lead to differences in priorities and r as ing-specif t disagreements about appropriate actions. For example, Schaeffer (in this ion ed f volume) describes the virtual stalemate between the Corps of Engineers and the peset y representatives of various resource management agencies and environmental publicat

her t groups regarding studies to assess the ecological effects of increased barge iles creat is h

t traffic on the upper Mississippi River. L f

M of

and ot If there are indeed systematic differences in the expectations of engineers X and ecologists, disagreements might not depend as much upon the particulars of om yles, r f the case in question as upon differences in fundamental disciplinary st version perspectives or assumptions, such as the time frames of consideration or print posed

e expectations regarding future technological developments. Perhaps engineers h heading who are accustomed to choosing design alternatives involving fairly well recom

use t Understood phenomena may naturally tend to focus on risks while ecologists, who are not so accustomed to making precise predictions, are naturally inclined breaks, ease l been

P to focus on unknowns and the possibility of unknown unknowns. An effort to

word

has get at the roots of these differences in perspective and focus, if they are real, ed.

hs, might lead to improved understanding all around and better mutual appreciation

insert of ecologists for engineering perspectives and vice versa.

ally Engineers deal with uncertainty regularly in their design efforts. Safety line lengt factors are routinely used to minimize the risk of hazards due to variables original work e h

t outside the designer's control. In essence, safety factors represent one way to try to insure against catastrophe. This is not unlike conventional approaches to he original;

ion of many everyday sources of uncertainty, where substantial sums are invested to t at o protect against the consequences of potentially catastrophic but uncertain events ue t r have been accident such as personal illness, automobile accidents, or military aggression (Daily et y t a al., 1991). One goal for collaborating engineers and ecologists could be to represent m are

l develop new ways to think about "safety factors" and other means to a incorporate the possible effects of uncertainties into considerations of human errors environmental impacts. age breaks P is new digit h pographic

y APPROACHES TO ENVIRONMENTAL CONTROL: LESSONS iles. T t

f e

ile: FROM RESOURCE MANAGEMENT EFFORTS ng i f t F

D There is no consensus regarding the precision with which humans can P peset and som is expect to manage ecosystems. Some feel that we can not expect to control the y h t

environment ined, a bout A ret original t

ion. om

r on scales larger than individual agricultural fields, whereas others are optimistic ibut f r t cannot about regional control strategies, and still others are optimistic about the r at not

o potential for control on global scales. Regardless of the ultimate potential of f human control, analyses of past resource management efforts provide important

however, lessons regarding pitfalls to avoid in control efforts. Like conventional version ng,

t engineering, resource management faces substantial challenges with regard to paper book, at ive uncertainties, problem definition, and the need to maintain the flexibility to shift at rm o course if necessary. riginal horit ic f

o Holling (1986, in this volume) describes the insights from a review of e h efforts to manage forest insects, forest fires, fisheries, and arid rangelands. t he aut t

om Managers typically enjoyed initial success in efforts to constrain one variable r as ing-specif t within narrow bounds, but this success led to economic developments that ion ed f depended on perpetuating those management strategies. These dependencies peset y increased the pressure to maximize the productivity of particular components of publicat

her t the managed systems and made it difficult to modify management practices. iles creat is h

t Agencies shifted their focus toward increasing their efficiency in maintaining L f

M of

and ot the initial programs, and in some cases larger socioeconomic objectives were X neglected. As a consequence, systems became simpler and less resilient to om yles, r f perturbations. Disturbances that previously would have had little effect on the st version ecosystems began to have significant impacts on the simpler systems. Holling print posed

e and his colleagues conclude that a loss of resilience is a consequence of the h heading imposition of stability upon one component of a naturally dynamic system. recom

use t Wodraska and yon Haam (in this volume) argue that managers must continually monitor the effects of their efforts and enjoy the flexibility to breaks, ease l been

P modify strategies when necessary. They note that Congress dictated particular

word

has water flow rates into the Everglades, but the timing and magnitude of the ed.

hs, prescribed flows exaggerated natural extremes and exacerbated existing

insert environmental problems. Wodraska and yon Haam would have preferred an

ally incremental approach that was flexible enough to make adjustments in response line lengt to new information. original work e h

t Holling (in this volume) notes that the rigid control approaches used in the 22 cases he reviewed differ from natural ecological controls, which tend to be he original;

ion of "soft" and overlapping. A variety of different controls tend to keep natural t at o systems within loose boundaries. Though bounded, the systems are dynamic ue t r have been accident and resilient to disturbances. For example, temperature regulation in y t a endotherms (loosely speaking, "warm-blooded" animals) is managed by at least represent m are

l five separate, mechanistically distinct sets of controls, evaporative cooling, a metabolic heat generation, regulation of blood flow, insulation, and habitat errors selection. Endotherms have flourished even though their normal body

age breaks temperatures are very near their lethal body temperatures. P is new digit

h Is it necessarily the case that control of one key variable leads to fragility pographic y iles. T t

f of the larger system? Can management objectives be achieved without e ile: ng i f destroying the resilience of the system being managed? To what extent could t F

D future engineering and management efforts simply facilitate natural processes P peset and som is so that those y h t

ined, a bout A ret original t

ion. om

r processes serve the purposes (e.g., flood control) that have traditionally been ibut f r t cannot served by single-variable control-based engineering efforts (Mitsch, in this r at not

o volume)? It seems likely that significant progress toward answering these sorts f of questions will require extensive, regular collaboration among engineers and

however, ecologists. version ng,

i t paper book, at ive at rm SHORT-TERM SOLUTIONS THAT AGGRAVATE LONG- o riginal horit

ic f TERM PROBLEMS o e h The resource management programs reviewed by Holling represent t he aut t

om situations where short-term solutions aggravated long-term problems. The same r as ing-specif t situation is probably the essence of most environmental problems. Inappropriate ion ed f short-term actions sometimes appear sensible because their long-term peset y consequences are either not recognized or not appreciated. Engineering within publicat

her t ecological constraints must anticipate when short-term solutions will exacerbate iles creat is h t

L f long-terms problems (Cairns, in this volume; Norton, in this volume).

M of

and ot Wodraska and yon Haam's description (in this volume) of the California X water supply system provides an example of the tension between short-and long- om yles, r f term goals. To supply water to 16,000,000 residents of southern California, st version earlier managers of the water system stretched tentacles out to water sources in print posed

e northern California and to other western states. Water flows through pipes as h heading large as 6 meters in diameter in an area prone to earthquakes. This has solved recom

use t the problem of providing water to the residents of the region, but it has led to a system whose operation depends on the integrity of a plethora of components, breaks, ease l been

P including long aqueducts and pumps that lift water more than 500 meters.

word

has The problem of supplying water has been solved for the time being, but the ed.

hs, solution has made the water distribution system brittle in the sense that it is

insert sensitive to earthquakes and other disturbances. In addition, adequate present

ally supplies relax immediate constraints on human immigration, which will lead to line lengt a larger regional population and concomitantly greater dependence on the water original work e h

t distribution system. (The present managers are now attempting to increase the system's resilience by building in redundancy of function through conservation he original;

ion of and wastewater reclamation, rather than simply increasing capacity by obtaining t at o new supplies.) ue t r have been accident Herman (in this volume) refers to several other examples where short-term y t a solutions aggravate long-term problems. His examples include highway represent m are

l "bypass" routes that attract development and thus result in greater traffic a congestion, and pest control efforts that lead to the evolution of pesticide- errors resistant pests. These situations have been described as cases of "revenge" by

age breaks the system and discussed under the rubric of "revenge theory" by Tenner (1991). P is new digit

h In other cases the conflict is not between the society's short- and long-term pographic y iles. T t

f interests, but between the individual's interests and the society's interests, as in e ile: ng i f the case of CFC-based air-conditioning systems. Costanza (in this volume) t F

D refers to situations where short-term incentives conflict with long-term goals as P peset and som is social y h t

ined, a bout A ret original t

ion. om

r traps. He argues that our tendency to fall into social traps results from the speed ibut f r t cannot of cultural evolution: societies change so rapidly that it is difficult to r at not

o incorporate long-term considerations into day-to-day decisions. He argues that f in order to eliminate social traps, short-term incentives must be brought into

however, correspondence with long-term incentives. version ng,

t Norton (in this volume) argues that decisions with long-term or widespread paper book, at ive implications should be based on different criteria than decisions whose at rm o implications are only local or ephemeral. He contrasts the individual's roles as a riginal horit ic f

o consumer and as a member of a constitutional convention. Norton argues that e h while the consumer makes economic decisions based on individual utility in the t he aut t

om relatively short run, the delegate to a constitutional convention must make r as ing-specif t decisions on the basis of the long-term best interests of the nation whose ion ed f constitution is being drafted. In other words, different priorities must serve as peset y the basis for decisions that have the potential for long-term effects, whether the publicat

her t issue is a nation's constitution or its environment. iles creat is h t

L f This is not to suggest that the short-term problems discussed above should

M of

and ot not have been "solved," merely that those searching for solutions should X recognize the potential for "revenge" on the part of the system. As Garrett om yles, r f Hardin (1993:16) suggests, when contemplating the effect of a particular st version solution, one should ask, "And then what?" We believe that the following print posed

e papers will help as engineers and ecologists consider Hardin's question in the h heading course of future attempts to engineer within ecological constraints. recom use t breaks,

ease ACKNOWLEDGMENTS l been P

word

has These remarks are based on discussions and presentations during an April ed.

hs, 1994 National Academy of Engineering meeting on engineering within

insert ecological constraints. George Diggs, Alexander Flax, Hugh MacIsaac, Deanna

ally Richards and three anonymous reviewers provided valuable comments on line lengt earlier drafts. Credit for any insights should be attributed to the meeting original work e h

t participants.

he original; ion of t at

o NOTES ue t r have been accident y t 1. Many definitions of sustainability have been proposed or implied. We use the term to refer to a situations where the environmental impacts of present human activities do not reduce the represent m are

l potential for the environment to support future human activities. The laws of thermodynamics a preclude truly infinite sustainability, but we consider this unimportant. With so many systems errors so far from sustainability at present, the concept is most useful as a guide in efforts to shift actions onto paths that appear to be more sustainable. Costanza (in this volume) elaborates on age breaks our conventional if loose definition by defining sustainability in terms of the expected life span P is new digit h

pographic of a system. Under his definition, if a system attained its expected life span, then it was y iles. T t

f sustainable. A species has a longer expected life span than a population, which has a longer e ile: ng

i expected life span than an individual, which has a longer expected life span than a cell. f t F

D 2. Assimilative capacity is the rate at which the environment can render wastes innocuous. P

peset 3. New technologies could conceivably also have unanticipated desirable consequences. and som is y h t

ined, a bout A ret original t

ion. om

r REFERENCES ibut f r t cannot Allenby, B. R. 1994. Integrating environment and technology: Design for environment. Pp. 137-148 r at not

o in The Greening of Industrial Ecosystems, B. R. Allenby and D. J. Richards, eds. f Washington, D.C.: National Academy Press. Allenby, B. R., and D. J. Richards, eds. 1994. The Greening of Industrial Ecosystems. Washington, however, D.C.: National Academy Press. version ng,

t Brooks, H. B. 1986. The typology of surprises in technology, institutions, and development. Pp. paper book, at ive 325-350 in Sustainable Development of the Biosphere, W. C. Clark and R. E. Munn, eds. at rm Cambridge, England: Cambridge University Press. o

riginal Cameron, J., and J. Abouchar. 1991. The precautionary principle: A fundamental principle of law horit ic f

o and policy for the protection of the global environment. Boston College International and e

h Comparative Law Review 14:1-27. t he aut t

Committee on Science, Engineering, and Public Policy. 1992. Policy Implications of Greenhouse om r

as Warming. Washington, D.C.: National Academy Press. ing-specif t Costanza, R. 1989. What is ecological economics? Ecological Economics 1:1-7. ion ed f Costanza, R. 1993. Developing ecological research that is relevant for achieving sustainability. peset

y Ecological Applications 3:579-581. Costanza, R., H. E. Daly, and J. A. Bartholomew. 1991. Goals, agenda, and policy publicat

her t recommendations for ecological economics. Pp. 1-20 in Ecological Economics: The iles creat is

h Science and Management of Sustainability, R. Costanza, ed. New York: Columbia t L f University Press. M of

and ot

X Daily, G. C., P. R. Ehrlich, H. A. Mooney, and A. H. Ehrlich. 1991. Greenhouse economics: Learn before you leap. Ecological Economics 4:1-10. om yles, r f Daly, H.E. 1990. Toward some operational principles of sustainable development. Ecological st version Economics 2:1-6. Gray, P. E. 1989. The paradox of technological development. Pp. 192-204 in Technology and print posed

e Environment, J. H. Ausubel and H. E. Sladovich, eds. Washington, D.C.: National h

heading Academy Press.

recom Hardin, G. 1993. Living Within Limits. New York: Oxford University Press.

use t Holling, C. S. 1986. Resilience of ecosystems: Local surprise and global change. Pp. 292-317 in

breaks, Sustainable Development of the Biosphere, W. C. Clark and R. E. Munn, eds. Cambridge, ease l been England: Cambridge University Press. P Holling, C. S. 1992. Cross-scale morphology, geometry and dynamics of ecosystems. Ecological word has ed. Monographs 62(4):447-502. hs, Holling, C. S. 1993. Investing in research for sustainability. Ecological Applications 3:552-555.

insert Kates, R. W., B. L. Turner II, and W. C. Clark. 1990. The great transformation. Pp. 1-17 in The Earth as Transformed by Human Action, B. L. Turner II, W. C. Clark, R. W. Kates, J. F. ally Richards, J. T. Matthews, and W. B. Meyer, eds. Cambridge, England: Cambridge line lengt

original work University Press. e

h Ludwig, D., R. Hilborn, and C. Waters. 1993. Uncertainty, resource exploitation, and conservation: t Lessons from history. Science 260:17,36. Myers, N. 1995. Environmental unknowns. Science 269:358-360. he original;

ion of Nordhaus, W.D. 1992. An optimal transition path for controlling greenhouse gases. Science t at o 258:1315-1319. Nordhaus, W. D. 1994. Expert opinion on climatic change. American Scientist 82:45-51. ue t r have been accident y

t Risser, P. G. 1995. Indication of grassland sustainability: A first approximation. Pp. 309-319 in a Defining and Measuring Sustainability: The Biogeophysical Foundations, M. Munasinghe represent m are

l and W. Shearer, eds. Washington, D.C.: The United Nations University. a Tenner, E. 1991. Revenge theory. Princeton Alumni Weekly, October 23. errors

Vitousek, P. M., P. R. Ehrlich, A. H. Ehrlich, and P. A. Matson. 1986. Human appropriation of the products of photosynthesis. BioScience 34:368-373. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not PERSPECTIVES ON ECOLOGY AND o f ENGINEERING however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html DETERMINING THE BALANCE BETWEEN TECHNOLOGICAL AND ECOSYSTEM 13 SERVICES e h t be

ion. om r ibut f r t cannot r at not Determining the Balance Between o f Technological and Ecosystem Services however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h John Cairns, Jr. t he aut t

om r as

ing-specif The significant problems we face cannot be solved at the same level of thinking t we were at when we created them. ion ed f

peset Albert Einstein y

publicat Every country can be said to have three forms of wealth: material, cultural and her t iles creat is

h biological. The first two we understand very well, because they are the t L f

M of substance of our everyday lives. Biological wealth is taken much less seriously.

and ot

X This is a serious strategic error, one that will be increasingly regretted as time om yles,

r passes. f st version E. O. Wilson print posed e h

heading ECOSYSTEM SERVICES: A MATTER OF PERCEPTION recom use t Society has become so accustomed to technological services that they are breaks,

ease obvious only in their absence. This happened recently in the eastern United l been P States during the ice storms and blizzards of 1994, in the Mississippi River word has ed. drainage during the severe floods of 1993, in Florida following Hurricane hs, Andrew in 1992, and in Georgia during the flooding of the Flint River in 1994. insert Technological services generally involve the substitution of fuels for human ally effort. They include delivering diverse foods independent of season or local line lengt original work

e climate; delivering potable water directly into homes; heating, cooling, and h t

humidifying or dehumidifying the climate in buildings; delivering communications such as telephone calls and television and radio signals; and he original; ion of t removing noxious wastes such as sewage and trash from homes. Civilization, at o especially in wealthy countries, has developed an extensive infrastructure for ue t r have been accident y t the delivery of technological services, including electrical transmission lines, a represent m roads, airports, telephone lines, satellites, and sewer systems. are

a Society also depends on ecosystem services that have existed for much errors

longer, in fact, probably since the appearance of life on Earth. Ecosystem services are those functions of ecosystems that society deems beneficial, age breaks

P including the maintenance of atmospheric gas balance, flood control, carbon is new digit h pographic storage, capture y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r of solar energy and subsequent production of food and fiber, maintenance of ibut f r t cannot water quality, and maintenance of a genetic library that provides the raw r at not

o materials for improved foods, materials, and drugs. While these services have f long been taken for granted, society is beginning to realize that many functions

however, of natural systems are not immutable and can be affected by human actions. version ng,

t The definition of an ecosystem service is a matter of societal perception paper book, at ive because it hinges on valuation. Of all the processes or functions carried on by at rm o ecosystems, only those contributing to the well-being of human society are riginal horit ic f

o considered services. On those rare occasions when the societal value of e h minimally managed functions of ecosystems is evaluated, different people reach t he aut t

om different conclusions. The debate is even more heated when management r as ing-specif t actions to protect ecosystem services are proposed. What scientific evidence is ion ed f necessary to facilitate the societal debate on value and help establish a peset y reasonable level of management? Does the delivery of necessary ecosystem publicat

her t services depend on ecosystem health? Not only is additional, well-conceived iles creat is h

t research needed to clarify these relationships, but it is also crucial to be able to L f

M of

and ot communicate the results of such research and its uncertainties to the wider X society that is properly involved in the debate on values. These issues provide om yles, r f recurring themes in the following discussion of balance. st version print posed e

h WHAT QUALIFIES AS AN ECOSYSTEM SERVICE? heading recom

use t All ecosystem functions could possibly be viewed as ecosystem services and any distinction between the two as a reflection of the limits of human breaks, ease l been

P knowledge rather than an actual difference. In addition to the term ecosystem

word

has services, the term sustainable use is often used to describe human benefits from ed.

hs, ecosystems. When an ecosystem service is being provided at a rate that meets

insert society's demands without compromising future use, there is sustainable use of

ally the ecosystem. However, as Costanza notes (in this volume): "The problem is line lengt that one knows one has a sustainable system only after the fact . Thus, what original work e h

t usually passes for definitions of sustainability are actually predictions of what set of conditions will actually lead to a sustainable system." The alternative is he original;

ion of an unsustainable use that not only may fail to meet the needs of society but also t at o may damage the ecosystem and impair the rate at which the desirable service is ue t r have been accident provided. y t a The least controversial examples of ecosystem services are those for which represent m are

l an economic value is easily derived. These economic values can then be a incorporated into existing decision making tools. The rapidly developing field errors of ecological economics (e.g., Costanza, 1989, 1991, and in this volume) has

age breaks identified several useful approaches. There are problems with these approaches, P is new digit

h but in their absence ecosystem services are too often completely ignored as pographic y iles. T t

f externalities. e ile: ng i f Some cases of free market respect for ecosystem services rather than t F

D technological ones can be cited. Natural systems are replacing chemical P peset and som is technology for waste treatment (Hammer, 1989). Natural systems complement y h t

energy-using ined, a bout A ret original t

ion. om

r technologies in local climate modification; for example, planting trees may save ibut f r t cannot 200 billion kilowatt-hours annually in the United States by reducing the need r at not

o for air conditioning (Committee on Science, Engineering, and Public Policy, f 1992). Avise (1994) calculated the cost of Biosphere 2, which partially

however, regulated the life-support systems for eight humans over a two-year period with version ng,

t an electricity subsidy from outside the sphere. The cost was $150 million paper book, at ive (U.S.), or $9 million per person per year. The complications of calculating per at rm o capita ecosystem services at vast global or continental scales were definitely not riginal horit ic f

o present in this mesocosm experiment. Nevertheless, there is little doubt that e h practices tolerated in Biosphere 1 (the earth), such as human population growth, t he aut t overexploitation of ecological capital, and massive destruction of habitats and om r as ing-specif t species, could not be tolerated in Biosphere 2 even for a relatively short time ion ed f (Avise, 1994). Clearly, some essential functions of natural ecosystems would be peset y difficult or expensive to replace through technological systems. publicat her t iles creat is h t L f ECOSYSTEM HEALTH AND THE PROVISION OF M of

and ot

X ECOSYSTEM SERVICES om yles, r f Ecosystem health is a complex concept, but a consensus definition has st version been derived (Haskell et al., 1992; see also Karr, in this volume): print posed e h

heading An ecological system is healthy and free from ''distress syndrome" if it is

recom stable and sustainable—that is, if it is active and maintains its organization and use t autonomy over time and is resilient to stress. breaks, ease l been P

It seems reasonable that a close correlation should exist between health word has

ed. and performance at any level of biological organization. Healthy plants capture hs, more solar energy. Growing forests store more carbon. Indeed, one definition of insert stress demands that captured energy be diverted from growth into coping

ally mechanisms (Calow, 1991). However, the relationship between ecosystem line lengt

original work health and ecosystem services is not as well defined. e h t

A number of interrelated hypotheses on the relationship between ecosystem health and ecosystem services deserve serious attention (Cairns and he original; ion of

t Pratt, 1995). at o 1. A close correspondence exists between ecosystem health and the ue t r have been accident y t production of ecosystem services. a represent m

are 2. Deterioration of ecosystem health does not affect the various ecosystem

l a services uniformly. errors 3. Ecosystem services decline monotonically with declines in ecosystem health. age breaks

P 4. Decline of ecosystem services important to human society can be is new digit h pographic

y predicted accurately from measures of ecosystem health. iles. T t

f e

ile: 5. Ecosystem services of importance to human society may vary markedly ng i f t

F even for ecosystems in robust health or condition. D 6. For ecosystems in robust health with highly variable delivery of ecosystem P peset and som is y h t

ined, a bout A ret original t

ion. om

r services, these changes can be predicted from climatic, life cycle, or other ibut f r t cannot similar information. r at not

o 7. Some ecosystem services are important globally and, therefore, must be f maintained at a global level, while some ecosystem services are local or

however, regional, so management at those levels could ensure appropriate delivery version ng,

t of services. paper book, at ive at

rm It has been suggested that some of these hypotheses are too broad to test, o

riginal while others are truisms. However, because these ecosystem services play a role horit ic f o

e in contributing to the life-support system of human society, they are matters of h t

he aut vital importance. To test these broad hypotheses, it may be necessary to t

r approach them, like other big and important issues, obliquely or piecemeal. as ing-specif t Bradshaw (1983) has said, ''The acid test of our understanding is not ion ed f

peset whether we can take ecosystems to bits on pieces of paper, however y scientifically, but whether we can put them together in practice and make them publicat her t

iles creat work." Bradshaw's statement is as valid today as it was more than a decade ago is h t L f when it was written. There is, however, a second test for ecology; namely, M of

and ot whether ecologists can document the services ecosystems provide in X

om sufficiently explicit terms that society will not only protect and preserve those yles, r f st version ecosystems still delivering such services but repair to whatever degree possible those ecosystems capable of delivering services at a level far beyond their print posed e present capacity. h heading Quantifying ecosystem services, while a formidable task, may not be as recom

use t esoteric as it appears. John Harte, of the University of California, Berkeley, has

breaks, carried out studies at Rocky Mountain Biological Laboratory in Colorado on the ease l been P

effects of global warming. During this research, he found that the soils at the word has

ed. laboratory itself acted as a methane sink. He estimated that, if one extrapolates hs, from that small patch to the entire county, the amount of methane assimilated insert by the soils approximately equals the amount of methane produced by the cattle

ally in the county. Not only is this information ecologically useful, but it can be line lengt

original work easily communicated to the ranchers and other inhabitants of the area. Put in a e h t

local context, ecosystem services are no longer regarded as an esoteric issue but as one of considerable interest to area residents. he original; ion of

t Some more specific questions related to the documentation of ecosystem at o services follow. ue t r have been accident

y 1. What is the relationship between species richness and delivery of t a ecosystem services? represent m are

a Biotic impoverishment, or loss of species, is fairly well documented (e.g., errors

Wilson, 1988), but the relationship between delivery of ecosystem services and the number of species present is almost certainly not linear. There is some

age breaks evidence of redundancy in function, which means that, if 10 or 12 species were P is new digit h

pographic carrying out roughly the same function simultaneously, the loss of one or two y iles. T t

e would not cause a serious decline in delivery of services because the ile: ng i f t deficiencies would be made up by the remaining species expanding their F

D numbers. P peset and som is y The decrease in species diversity, and presumably services provided by h t ecosystems ined, a bout A ret original t

ion. om

r subject to sustained pressure by humans, appears widespread. Regier and ibut f r t cannot Hartman (1973) provide an interesting account in which valued sport and r at not

o commercial fish were exterminated in Lake Erie as a result of tremendous f fishing pressure. These species were replaced by less valuable ecological

however, equivalents. The substitute species still provide "services," though not of the version ng,

t same commercial value as those potentially contributed by the exterminated paper book, at ive native species. at rm o Other evidence indicates that what appears to be redundancy is not riginal horit ic f

o redundancy. For example, although two different species of zooplankton may e h feed on phytoplankton in lakes, one may be much more selective than the other, t he aut t

om thus producing different ecological consequences. Selective feeders remove r as ing-specif t individuals of only certain species from a community. This gives the remaining ion ed f species, those not chosen, a considerable advantage since their competitors are peset y removed and the resources used by the competitors will almost certainly publicat

her t become available to the remaining species. This produces a marked alteration in iles creat is h

t community structure, as often occurs in rangeland cattle grazing when the most L f

M of

and ot succulent plant species are removed and the less succulent species (e.g., thorny X shrubs) become dominant or at least much more abundant. Nonselective om yles, r f feeding, on the other hand, is more equitable and is more likely to produce st version similar reductions in the various prey species. Thus, selective feeding is likely print posed

e to alter the relative abundance of species present, whereas nonselective feeding h heading is likely to have much less effect on the relative abundance of species. recom

use t 2. How close is a crucial break point, or threshold, in the delivery of services by natural ecosystems? breaks, ease l been

P There is good documentation of the increase in human population as well

word

has as the marked increase in technological and industrial activity, particularly ed.

hs, energy consumption from fossil fuels. Since human population numbers, levels

insert of affluence, and use of technology have increased dramatically in the past

ally 10,000 years, and ecosystem services still appear adequate to support life line lengt (although regionally impaired here and there), one may ask whether delivery of original work e h

t ecosystem services is really an important problem? 3. To what degree are the ecosystem services of natural systems replaced he original;

ion of by agroecosystems, managed forests, and even such things as vegetation on golf t at o courses? As Harte (1993) notes: ue t r have been accident y t

a When trees are cut and all or some of the wood and foliage is left to rot, the represent m are

carbon in the tree is oxidized to carbon dioxide. Since about one-third of a tree, l a by weight, is carbon, a good deal of carbon dioxide can be produced when a errors

large area of forest is felled. Even if the cleared land is planted with crops, the carbon that can be stored in cropland is vastly less than that in the forest it age breaks replaced. P is new digit h pographic y iles. T t

f 4. To what degree do natural systems provide global, regional, or local e ile: ng i f services? t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r For the maintenance of atmospheric gas balance, one could make a fairly ibut f r t cannot strong case for hemispheric management. For protecting water quality, a r at not

o regional management for services might be more effective and, for aesthetic f purposes, highly local management is called for (see also Norton, in this

however, volume). version ng,

t 5. Can one extrapolate from the services provided by one ecosystem to the paper book, at ive services likely to be provided by another? at rm o Of course, one would not expect to extrapolate ecosystem services from riginal horit ic f

o the Kalahari Desert to the California redwood forests with any substantive e h degree of correspondence. However, one might reasonably expect to be able to t he aut t

om extrapolate from one East Coast temperate zone wetland to another. The degree r as ing-specif t of uniqueness of each ecosystem and the degree to which extrapolations can be ion ed f made with confidence will require a robust database, which can probably be peset y gathered relatively efficiently. publicat

her t 6. What is the relationship between ecological resilience and the delivery iles creat is h t

L f of ecosystem services (see Holling, in this volume)?

M of

and ot Ecosystems have, throughout their existence, been exposed to natural X perturbations, such as drought, hurricane damage, fires, and floods. Resilience, om yles, r f as defined by Holling (1973), is the ability to regain normative or characteristic st version structural or functional attributes following a perturbation. Some ecosystems are print posed

e thought to be perturbation-dependent and others perturbation-independent (e.g., h heading Vogl, 1980). Will full ecosystem services resume more quickly in the former recom

use t than in the latter? 7. To what extent do exotic invading species disrupt or impair ecosystem breaks, ease l been

P services?

word

has As a result of human transportation, animals and plants now have means of ed.

hs, dispersal that were not available previously. The new colonists can wipe out or

insert displace native species, and are frequently dispersed alone, without the control

ally measures (predators, parasites) that keep them in check in their original habitat. line lengt The rate of human transport of exotics to new habitats will increase markedly as original work e h

t the global marketplace develops. How will these assisted invasions affect delivery of ecosystem services? he original; ion of t at o COMMUNICATING THE LINKAGES BETWEEN NATURAL ue t r have been accident y t SYSTEMS AND HUMAN WELL-BEING a represent m are

l Any attempt to balance technological and ecosystem services must be a supported by the general public. To be included in the debate, it is essential that errors the general public have access to the information that ecologists take for

age breaks granted. It will be necessary to communicate convincingly to a majority of a P is new digit

h country's inhabitants that they themselves are dependent on services provided pographic y iles. T t

f by natural systems. If this dependence is not understood, then the drive to e ile: ng i f protect wild areas t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r and ecosystem services will be characterized as an extravagance driven by ibut f r t cannot religious beliefs rather than sensible self-interest. That is why scientific r at not

o investigations of the linkages between environmental services and human f quality of life are essential.

however, At present, environmental literacy is rudimentary for most members of version ng,

t human society, including college graduates in many disciplines (e.g., Wallace et paper book, at ive al., 1993). There is a widespread belief that there are technological solutions to at rm o every problem and that stabilizing the size of human population will lead to riginal horit ic f

o economic stagnation. e h Skinner (1983) argued persuasively that human behavior is selected or t he aut t

om determined by its consequences and that substantial numbers of people cannot r as ing-specif t be expected to change their behavior as the result of information or advice ion ed f alone, especially when the information is about a distant future. He further peset y stated that people might follow advice when the information from the advice publicat

her t giver has led to beneficial consequences in the past; however, this situation iles creat is h

t requires that people have experienced reinforcing consequences of prior L f

M of

and ot compliance with similar advice givers or similar rules. Such operant learning is X difficult or impossible when reinforcement lies in the future or punishing om yles, r f consequences are unclear, uncertain, or remote. Lack of clarity, uncertainty, and st version remoteness are all common characteristics in the models scientists must use to print posed

e make large-scale predictions about ecosystems. A major ecological disaster h heading would provide persuasive evidence of the links between human and recom

use t environmental health, and failures of some technological solutions would radically change human society's relationship to natural systems. breaks, ease l been

P Rather than wait for severe consequences, what events are most likely to

word

has change human behavior with a modest increase in environmental literacy? ed.

hs, Professionals in various disciplines must make the added effort to combine their

insert contributions to facilitate policy and decision making. The obvious example of

ally this is ecological economics. Professionals must also make their information line lengt and conclusions accessible to the public. Science reporting for the mass media original work e h

t is improving and has room to continue to do so. Another area of concern in environmental literacy is the way in which ecologists, managers, and engineers he original;

ion of communicate the uncertainties inherent in their projects. t at o ue t r have been accident y t MANAGED COEVOLUTION a represent m are

l Although human society is well into the information age in world trade, a economics, military strategy, marketing, investment, and a host of other errors activities, the use of information feedback loops to modify society's relationship

age breaks to ecosystems has not progressed nearly as far as it has in other areas. A major P is new digit

h reason for this curious discrepancy is that the consequences of failure in pographic y iles. T t

f military, economic, and other sectors of society are more apparent to e ile: ng i f policymakers than are comparable failures in ecological systems. In contrast, t F

D the consequences of P peset and som is y h t

ined, a bout A ret original t

ion. om

r ill-coordinated responses to changes in ecosystems may not be intrusive until ibut f r t cannot much time has elapsed. r at not

o In ecological systems, one form of information feedback is coevolution, a f term first used by Ehrlich and Raven (1964) in examining the evolution of

however, plants and the insects that feed on them. They defined coevolution as a pair- version ng,

t wise process in which the appearance of a trait in one species elicits a response paper book, at ive in another species. For example, increased speed in a carnivorous mammal may at rm o result in increased speed in its prey, or a variety of other adaptations to offset riginal horit ic f

o the predator's speed, such as improved camouflage. Futuyama and Slotkin e h (1983) indicated that development of a particular trait in one or more species t he aut t may result in a suite of traits in several other species. Ghersa et al. (1994) om r as ing-specif t described the coevolution of agroecosystems and weed management. They ion ed f postulate that weed-management practices have become closely linked to social peset y and economic, rather than biological, factors. As Harlan and deWet (1965) have publicat

her t noted, weeds and weed problems are anthropocentric terms applied to iles creat is h

t populations of plants when they are considered undesirable. L f

M of

and ot Before the agricultural revolution, the needs of Homo sapiens were met in X ways not dramatically different from the ways in which needs of other species om yles, r f were met. Human populations were comparatively small and kept from the st version explosive growth of the past century by disease, starvation, and even predation. print posed

e These are, in fact, much the same population control factors affecting other h heading species. Throughout history, ecosystems provided all the services necessary for recom

use t the continuation of the human species: breathable air, potable water, food, and a consistent climate over the short-term. Now human society has a codependence breaks, ease l been

P on both a technological life-support system and an ecological life-support

word

has system. However, the maintenance needs of technological services get much ed.

hs, more attention than those of ecosystem services. In a very real sense, natural

insert systems and human systems are coevolving since only those opportunistic and

ally communal species tolerant of the anthropogenic alterations of natural systems line lengt are likely to thrive. These may be opportunistic species resistant to pesticides original work e h

t and habitat fragmentation and tolerant of a wide range of ecological conditions— in short, pests. he original;

ion of Those species that are tolerant of anthropogenically changed conditions t at o might provide some of the services that more complex natural ecosystems ue t r have been accident provided previously. However, it seems unlikely that they will perform in y t a precisely the same ways. Kauffman (1993) proposes a bold hypothesis: represent m are

l complex, adaptive systems operate on the edge of chaos. He feels that not only a organisms, but economic entities and nations, do not simply evolve, but rather errors coevolve, and that coevolving complex systems mutually operate at the edge of

age breaks chaos. If the adapting system is itself in the ordered (rather than the chaotic or P is new digit

h boundary) regime, Kauffman (1991, 1993) believes the system itself adapts on a pographic y iles. T t

smooth landscape (see Holling, in this volume). In the chaotic regime, the f e ile: ng i f system adapts on a very rugged landscape, and, of course, in the boundary t F

D regime, it is intermediate. P peset and som is y h t

ined, a bout A ret original t

ion. 1 om

r Kauffman uses the word landscape in association with the word fitness, a ibut f r t cannot term commonly used in ecology to mean the degree of adaptation to the habitat r at not

o or ecological niche of an individual species. I suspect it can also describe the f goodness of fit of two complex, multivariate systems to each other. Kauffman

however, uses chaos in a technical sense, whereas in this discussion it is used in a more version ng,

t colloquial sense. However, it seemed important to begin this discussion with paper book, at ive Kauffman's publications. at rm o With Kauffman's analysis in mind, this author draws three conclusions riginal horit ic f

o about the balance between technological and ecosystem services: (1) abrupt e h changes are not prudent in the coevolution of complex, multivariate systems, t he aut t

om (2) in two coevolving systems with substantive interdependence, chaos in one is r as ing-specif t likely to result in chaos in the other, and (3) coevolution can drain energy and ion ed f deplete resources of the coevolving partners, as in the case of predator and prey. peset y This is also true for nations coevolving in a climate of hostility, as was the case publicat

her t for the USSR and the United States during the Cold War. Finally, coevolution is iles creat is h

t likely to proceed most smoothly if at least one of the parties recognizes the L f

M of

and ot dynamics of the situation. X In the coevolution of a predator species and its prey (the prey evolving om yles, r f toward more elusiveness and the predator increasing its foraging efficiency), st version one might make the case that the relationship is beneficial to both species print posed

e because the capabilities of each species are thereby improved. However, less h heading benign forms of coevolution are also evident. Application of pesticides leads to recom

use t pesticide resistance in the target organisms, thereby requiring more and more pesticides to achieve the same result and ultimately increasing the risks to breaks, ease l been

P nontarget species, including humans. Thus, the application of pesticides, if not

word

has done skillfully, can pose a serious threat to human health, a situation well ed.

hs, documented in the literature. As a consequence, one might reasonably ask if the

insert coevolution of human society and natural systems is mutually beneficial or

ally mutually destructive. Since the beginning of the agricultural revolution, society line lengt has attempted to alter natural systems so that more and more of the energy original work e h

t captured by photosynthesis is converted to foodstuffs and other products of interest to human society (Vitousek et al., 1986). Not only has there been a he original;

ion of substantial loss of space devoted to unmanaged production of diverse ecosystem t at o services as a result of agricultural activities, but relatively natural ecosystems, ue t r have been accident particularly those adjacent to agroecosystems, have often been affected by y t a runoff and airborne contaminants such as pesticides and dust, fragmentation, represent m are

l and, finally, changes in microclimate. It seems possible that this could represent a hostile coevolution. Erwin (1991) states, "Within a few hundred years this errors planet will have little more than lineages of domestic weeds, flies, cockroaches,

age breaks and starlings, evolving to fill a converted and mostly decertified environment P is new digit

h left in the wake of nonenvironmentally adaptive human cultural evolution." The pographic y iles. T t

pesticide tolerance and increased pesticide use described earlier are one such f e ile: ng i f example. In hostile coevolution, the deleterious effects of human society on t F

D natural ecosystems will select for those organisms P peset and som is y h t

ined, a bout A ret original t

ion. om

r and communities of organisms most resistant to this stress, with an equal ibut f r t cannot selection for pioneering species capable of taking advantage of chaos. More r at not

o than 100 years ago, Kew (1893) provided an eerie insight into the kinds of f species that would coevolve with human society if hostile coevolution

however, continues. He described the durability and colonizing potential of Dreissena version ng,

t (the zebra mussel), which relatively recently became a major problem in North paper book, at ive America (Ludyanskiy et al., 1993), as follows: at rm o riginal horit ic f The Dreissena is perhaps better fitted for dissemination by man and o

e subsequent establishment than any other fresh-water shell; tenacity of life, h t he aut

t unusually rapid propagation, the faculty of becoming attached by string byssus

om r as ing-specif to extraneous substances, and the power of adapting itself to strange and t

ion altogether artificial surroundings have combined to make it one of the most ed f

peset successful molluscan colonists in the world. y publicat

her t Thus, even if ecological losses or problems can be predicted, it seems as iles creat is h

t though society is often willing to trade these problems for jobs, particularly in L f

M of

and ot uncertain economic times (i.e., during recessions). Pratt and O'Connor (1994) X describe a situation at Gettysburg Historic Park, where certain conditions that om yles, r f existed at the time of Pickett's charge across a cornfield were to be maintained st version for historical reasons. The cornfield was located between two lines of trees. print posed

e During the Civil War, only a few deer inhabited the area. Deer were controlled h heading by hunters, who could harvest a substantial percentage of the population. At that recom

use t time, deer were not protected either by legislation or by being adjacent to areas where hunting would be highly objectionable. For many years, farmers were breaks, ease l been

P willing to pay a modest fee to grow corn in this historic area because they could

word

has harvest enough to make a profit. Eventually, the deer herd expanded to a size ed.

hs, that made harvesting corn no longer profitable. In addition, harvesting the deer

insert at the necessary rate was objectionable to components of society for a variety of

ally reasons. Replacing the cornfield with astroturf or some other nonhistoric line lengt condition was also unacceptable. Under the best circumstances, a substantial original work e h

t expenditure would be necessary to preserve the historic condition of the area by excluding the deer. Consequently, the coevolution of the deer herd and human he original;

ion of society became more and more expensive with no socially acceptable t at o alternative in view. In this example, the natural control measures regulating the ue t r have been accident deer population were removed and resulted in densities unlikely to have been y t a achieved previously in natural systems. All this occurred because humans represent m are

l provided an extraordinary food base and freedom from predation for the deer. a Chaos at the interface can be manifested in a variety of ways. A errors contrasting illustration for an aquatic system is the invasion of North America

age breaks by the Asiatic clam, the zebra mussel, and the quagga mussel (Russian mollusc, P is new digit

h D. bugensis). These invaders from different parts of the world might well have pographic y iles. T t

taken hold in pristine systems in North America had they been able to get there. f e ile: ng i f However, without the help of human society's transportation system, this would t F

D have been P peset and som is y h t

ined, a bout A ret original t

ion. om

r unlikely. Not only can these molluscs invade areas occupied by North American ibut f r t cannot species, but they can also occupy habitats created by an industrial society, such r at not

o as power plant cooling systems, irrigation canals, waste treatment ponds, and, in f the case of the zebra mussel, surfaces such as ship hulls (e.g., Cherry et al.,

however, 1986; Garey et al., 1980; Hayward et al., 1982; Nalepa and Schloesser, 1993). version ng,

t In addition to the problems caused in the technological portion of human paper book, at ive society, there is also an increased risk to natural systems resulting from the at rm o marginally effective control measures designed to minimize the impacts of riginal horit ic f

o these species on the industrial system, including agro-industry. These invaders e h of North America have created chaos in both the technological and the t he aut t

om ecological components of human society's life-support systems. r as ing-specif t Thus, while there is ample cause for concern about biotic impoverishment ion ed f (e.g., Wilson, 1988), there seems to be little concern about the ultimate peset y consequences of this coevolutionary process. If the assumption is that humans publicat

her t are incapable of driving all species to extinction, those left will be highly iles creat is h t

L f adapted to exploit the new environmental conditions resulting from

M of

and ot overemphasis on the maintenance of technological services. Pest species will be X difficult to eradicate—those capable of invading habitats unsuitable for most om yles, r f other species; those selected for resistance to pesticides and other control st version measures; and, in many instances, those so intimately associated with human print posed

e society (such as the Norway rat, the housefly, and the cockroach) that control h heading measures may also be a risk to human health. However, failure to exercise the recom

use t control measures may pose an equal danger to human health as a result of spread of disease. breaks, ease l been

P Nonsuch Island provides excellent examples of the ability of exotic species

word

has to colonize, as do the Hawaiian Islands and many other island ecosystems. On ed.

hs, Nonsuch, Wingate (1990) reported the necessity of a major and continuous

insert effort to eliminate invading species. Plant invaders are brought to Nonsuch from

ally other Bermuda islands by birds that feed there and then defecate the seeds and line lengt other propogules while roosting at night. Even reestablishing the species that original work e h

t existed on the islet before heavy colonization by Europeans would not enable that community to resist invasion by exotics if the sources of colonizing species he original;

ion of were in either the conterminous or contiguous ecological landscape in which t at o Nonsuch exists. ue t r have been accident Although experimental evidence is not robust, one might still reasonably y t a conclude that, once human society has created chaos in a natural system by represent m are

l destabilizing a complex system, the new system, whatever ecologists may think a of it, is now a coevolutionary partner with human society. This plausible errors analysis provides grounds for persuading human society to consider the

age breaks coevolutionary consequences of the impact of its technological life-support P is new digit

h system on its natural life-support system. pographic y iles. T t

f The situation described as hostile coevolution is a form of "social trap." e ile: ng i f The social trap in this case is the feeling that any major change in human t F

D behavior will result in such chaos in the economic system that the natural P peset and som is systems will just have y h t

ined, a bout A ret original t

ion. om

r to take it. Besides, the reasoning goes, there is no "scientific proof" of any ibut f r t cannot failure in ecosystem services, and most predictions of the consequences of loss r at not

o of biodiversity, global warming, ozone holes in the atmosphere, and the like f seem much less threatening than job loss, reduction in gross national product, or

however, loss of present amenities resulting from high per capita energy consumption and version ng,

t lowered product costs because environmental externalities are not included in paper book, at ive economic analyses. Substantial literature exists on social traps, but some at rm o illustrative materials are Brockner and Rubin (1985), Cross and Guyer (1980), riginal horit ic f

o Platt (1973), Teger (1980), and, particularly relevant to this discussion, e h Costanza (1987, and in this volume) and Geller (1994). t he aut t

om r as ing-specif t ion

ed f BALANCING TECHNOLOGICAL AND NATURAL SERVICES peset y In developing a guiding model for achieving a balance between publicat

her t technological and ecosystem services, it is helpful to see what humans did when iles creat is h t

L f the technology was primitive and human populations comparatively small. At

M of

and ot least some preindustrial tribes revered their local environment, but Diamond X (1992, 1994) has suggested that the relationships between primitive peoples and om yles, r f their natural environments were not always sustainable. Probably the best st version known, much earlier exponent of this outlook was Rousseau (1754), whose print posed

e discourse on the origin of inequality traced humanity's degeneration from the h heading golden age to the misery that now exists in all too much of the world. recom

use t Where peoples living in harmony with nature persist, they have been driven to areas that no one else wants. This is true of the Bushmen in the breaks, ease l been

P Kalahari Desert and some of the few remaining indigenous societies in the

word

has Amazon basin and parts of Australia. Since the agricultural revolution some ed.

hs, 10,000 years ago, the agrarians have always outnumbered the hunters and

insert gatherers and, even if they were less skillful in warfare, could overwhelm them

ally by sheer numbers. Some of the literature that is particularly interesting in this line lengt regard is Hughes (1975), Kirch (1984), Martin (1973), Martin and Klein (1984), original work e h

t Mosimann and Martin (1975), Samuels and Betancourt (1982), and Yoffee and Cowgill (1988). Despite uncertainties and controversy about the literature from he original;

ion of which these selections are taken, it is clear that even the primitive technologies t at o of human society when used with teamwork and intelligence could cause ue t r have been accident considerable environmental havoc. y t a Ornstein and Ehrlich (1989) speculate that there could be no selective represent m are

l pressures likely to result in a genetic trait prohibiting excessive depletion of a resources or conditioning an individual toward long-term sustainable use of a errors resource base. The rewards for exploitative behaviors are too immediate; the

age breaks consequences too delayed. Even if the level of technology used by the hunters P is new digit

h and gatherers was acceptable to human society (which is no longer the case), pographic y iles. T t

population densities alone preclude using such a model, at least for many f e ile: ng i f generations. Of course, many species are left, so, as Diamond notes, the golden t F

D age may not have been as golden as it was thought to be, but neither was it all P peset and som

is black. Human y h t

ined, a bout A ret original t

ion. om

r population growth cannot continue at present rates indefinitely without ibut f r t cannot temporary and possibly irreparable damage to ecosystem services. r at not

o However, as a caveat, human society is probably unlikely to eliminate all f the species on the planet, especially since some of them are capable of living in

however, thermal vents on ocean floors and in other nearly equally inhospitable version ng,

t environments. It is also important to remember that much ecological damage paper book, at ive has been done and is being done by people who are suddenly thrust into a new at rm o ecosystem and transpose methods suitable for an entirely different ecosystem to riginal horit ic f

o the new one. In this regard, much may be learned from examining society's e h response both to technological advances, such as the agricultural revolution, and t he aut t to the displacement of large groups of people, such as pioneers, into new om r as ing-specif t ecological systems and habitats. ion ed f Agriculture appears to have had its origins approximately 10,000 years ago peset y in the Near East (Quinn, 1992). Probably the most positive feature of this publicat

her t revolution is that many times more people could be supported per unit area iles creat is h t

L f under an agricultural than a hunter/gatherer system. This concentration of

M of

and ot people accelerated the spread of diseases but also made possible the division of X labor, which could lead to either art or war. The agricultural revolution made it om yles, r f possible for a relatively few people to feed much larger numbers, and this in st version turn made the industrial revolution possible. print posed

e Multistory buildings, elevators, fossil fuel transportation, and the like made h heading it possible for enormous numbers of people to live in a relatively small area— recom

use t people who, for the most part, have infrequent interactions with natural systems and therefore are unfamiliar with how they work. This is particularly true of breaks, ease l been

P policymakers, elected officials, captains of industry, and others who may have

word

has high technological literacy but relatively low environmental literacy. Even ed.

hs, people in agribusiness, mining, and ranching, though far removed from cities,

insert may have only the most superficial interactions with systems that have

ally substantial biological integrity. The people most familiar with natural systems line lengt are not usually in positions of power and are probably not frequently consulted original work e h

t by those who are. Balancing technological and natural life-support systems will be exceedingly difficult if the operational prerequisites of the natural systems he original;

ion of are not well understood and the prerequisites of the technological system are. t at o ue t r have been accident y t PATH FORWARD a represent m are

l Unless the global population stabilizes, it seems unlikely that a balance a between technological and ecosystem services can be achieved. The United errors Nations report Children and the Environment quoted in the San Francisco

age breaks Chronicle July 20, 1990, noted that fewer than 1.5 billion people, less than half P is new digit

h the number alive in 1968, have yet achieved the standard of living that most pographic y iles. T t

f Americans (or citizens of other rich nations) would find acceptable. In short, the e ile: ng i f present technological and natural life-support systems of the planet are not t F

D functioning P peset and som is y h t

ined, a bout A ret original t

ion. om

r in a way that most inhabitants of developed countries would consider ibut f r t cannot ''necessary.'' Yet, the planet has a net gain of 95 million people annually. It is r at not

o difficult to be optimistic about either stabilizing or reducing the human f population when both men and women in many countries want a number of

however, children far beyond the replacement rate. For example, in Niger, women still version ng,

t want 8.5 children, although men want 12.6 on the average (e.g., Sachs, 1994). paper book, at ive If the human population is stabilized or approaching stabilization, it would at rm o be worthwhile to attempt to achieve concomitantly a no-net-loss of ecosystem riginal horit ic f

o services locally, regionally, and globally. This would mean a balance between e h destruction and repair of ecosystems with the proviso that destruction is usually t he aut t

om accomplished much more rapidly than repair, although in some cases both can r as ing-specif t be incremental. A stable human population coupled with a no-net-loss of ion ed f environmental services would mean that, if there were equitable distribution of peset y both, the ecosystem services per capita would not diminish from the time that publicat

her t stabilization and no-net-loss were simultaneously achieved and maintained. iles creat is h

t Ehrlich and Ehrlich (1991) have stated that the present population density and L f

M of

and ot level of affluence are possible only because society is expending ecological X capital, such as topsoil, old-growth forests, fossil water, and ocean fisheries, at om yles, r f rates that are not sustainable (i.e., far greater than the rates of replenishment) for st version many more years, let alone hundreds of years or millennia. Achieving a long- print posed

e term, sustainable-use balance between technological and natural life-support h heading systems will require replenishing ecological capital at the rate it is being used recom

use t (Daly, 1990). One problem with this approach is that the rates of replenishment of soils and aquifers are difficult to calculate on a short-term basis, and, for breaks, ease l been some things such as old-growth forests, it is not clear whether even millennia P

word

has will be adequate in some locations. Nevertheless, achieving a balance between ed.

hs, replenishment and depletion of ecological capital will be an important

insert consideration in achieving the balance discussed here.

ally The transition from expenditure of ecological capital to living entirely on line lengt ecological "interest" (i.e., services) might be improved by restoring a substantial original work e h

t number of damaged ecosystems, particularly those providing highly desirable services. It is worth emphasizing that these services can include recreational he original;

ion of values or aesthetic values. The National Research Council (1992) provides t at o illustrative targets for restoring aquatic ecosystems. This debate should focus on ue t r have been accident the types of ecosystems, the area or size of the restoration effort, the time frame y t a within which the effort should be made (conditioned, of course, by the fact that represent m are

l biological systems may be capable of reaching a new equilibrium only after a substantial time periods), and what should be done nationally, regionally, and errors locally. These are but a few of the many topics that should be discussed.

age breaks Initially, restoration need not affect prime agricultural or urban sites. There are P is new digit

h numerous abandoned or derelict damaged ecosystems, such as mined sites or pographic y iles. T t

floodplain farmlands (150 million acres in the United States), that could easily f e ile: ng i f be restored without interfering with the technological life-support system, and t F

D these P peset and som is y h t

ined, a bout A ret original t

ion. om

r should, of course, be restored first. However, inevitably, the time will come ibut f r t cannot when society must consider which should have the highest priority—the r at not

o technological or the ecological life-support system. The technological life- f support system is getting almost exclusive attention, and the ecological life-

however, support system practically none for reasons already discussed. However, version ng,

t assuming that the damage to the ecological life-support system cannot continue paper book, at ive indefinitely, a time will come when trade-offs must be made between the two at rm o systems. riginal horit ic f

o Until there is more robust information on the services provided by the e h ecological component of society's life-support system, several steps can be t he aut t

om taken to keep options open. r as ing-specif t 1. A diverse array of habitats should be maintained in as nearly pristine form ion ed f

peset as possible so that their ecosystem services can be measured. These will y provide models for reconstructing damaged ecosystems and also furnish publicat her t

iles creat information on the impairment of ecosystem services, if any, when these is h t L f habitats are used for a multiplicity of purposes as opposed to leaving them M of

and ot in their wild state. These pristine habitats also serve educational roles. X

om 2. The biotic impoverishment, or loss of species, that is occurring globally at yles, r f st version a disturbing rate should be substantially decreased as a matter of prudence until more is known about the relationship between biodiversity and print posed e ecosystem services. Of particular concern are migratory species, such as h heading birds, which may provide a variety of ecosystem services, many of which recom

use t are not yet recognized. The crucial issue for migratory species is the fact

breaks, that a loss of habitat anywhere in their migratory cycle could result in ease l been P

their extinction or cause a dramatic reduction in population size and, thus, word has

ed. affect ecosystem services at points distant from the area of lost habitat. hs, 3. If reaching the maximum possible number of humans on the planet is a insert societal goal, there should be at least some discussion of whether this goal

ally is most likely to be achieved over a long period through sustainable use or line lengt

original work through the depletion of ecological capital as is now being done. If e h t

achieving the maximum possible number of humans is not a goal, some discussion of the desirable population size and the human condition he original; ion of

t permitted by that size is necessary. at o 4. Enlightened discussion of the issues raised here will require a level of ue t r have been accident

y both environmental and technological literacy far beyond that now t a acquired by most graduates of educational institutions. Wholesale represent m are

a changes in beliefs may also be required to break the "jobs first, then errors

environmental protection" mindset. These changes are likely to occur only following enhanced education.

age breaks 5. As society moves toward a global economy, it is essential to move toward P is new digit h

pographic global consensus on society's relationship to the ecological portion of the y iles. T t

e life-support system. ile: ng i f t 6. Financial and other incentives should be devised to ensure that the F

D appropriate data are gathered and that a group of professionals competent P peset and som is y to make these measurements and judgments is produced by the h t educational system. ined, a bout A ret original t

ACKNOWLEDGMENTS I am indebted to Bruce Wallace, B. R. Niederlehner, and Eric Smith for commenting on a rough first draft of this manuscript and to John Harte and William Calder for useful comments and information for the third draft. I am equally indebted to Teresa Moody for transcribing the dictation of the manuscript and for making the many adjustments necessary in subsequent drafts, and to Darla Donald for editorial work so necessary in ensuring that the manuscript meet the requirements for publication.

the authoritative version for attribution. NOTE ing-specific formatting, however, cannot be

1. Ecologists use the term fitness in both a population and a genetic sense. Kauffman appears to have used it in the population sense in which the most fit species (i.e., those able to use the resources of a habitat most competitively) both increase their population size and have individuals in better physiological condition than individuals that are less "fit."

REFERENCES

Avise, J.C. 1994. The real message from Biosphere 2. Conservation Biology 8(2):327-329. Bradshaw, A. D. 1983. The reconstruction of ecosystems. Journal of Applied Ecology 20:1-17. Brockner, J., and J. Z. Rubin. 1985. Entrapment in Escalating Conflicts: A Social Psychological Analysis. New York: Springer-Verlag. Cairns, J., Jr., and J. R. Pratt. 1995. The relationship between ecosystem health and delivery of ecosystem services. In Evaluating and Monitoring the Health of Large-Scale Ecosystems, D. J. Rapport, ed. Germany: Springer-Verlag. Calow, P. 1991. Physiological costs of combating chemical toxicants: Ecological implications. Comparative Biochemistry and Physiology 100C:3-6. Cherry, D. S., R. L. Roy, R. A. Lechleitner, P. A. Dunhardt, G. T. Peters, and J. Cairns, Jr. 1986. Corbicula fouling and control measures at the Celco Plant, Virginia. Pp. 69-81 in Proceedings of the 2nd International Corbicula Symposium, Special Edition No. 2 of the American Malacological Bulletin. Committee on Science, Engineering, and Public Policy. 1992. Policy Implications of Greenhouse Warming. Washington, D.C.: National Academy Press. Costanza, R. 1987. Social traps and environmental policy. BioScience 37:407-412. Costanza, R. 1989. What is ecological economics? Ecological Economics 1:1-7. Costanza, R. 1991. Ecological Economics: The Science and Management of Sustainability. New York: Columbia University Press. Cross, J. G., and M. J. Guyer. 1980. Social Traps. Ann Arbor, Mich.: University of Michigan Press. Daly, H. E. 1990. Toward some operational principles of sustainable development. Ecological Economics 2:1-6. Diamond, J. 1992. The Third Chimpanzee. New York: Harper Collins. Diamond, J. 1994. Ecological collapses of ancient civilizations: The golden age that never was. Bulletin of the American Academy of Arts and Sciences 47(95):37-59. Ehrlich, P. R., and A. H. Ehrlich. 1991. Healing the Planet. Menlo Park, Calif: Addison-Wesley. Ehrlich, P. R., and P. H. Raven. 1964. Butterflies and plants: A study in coevolution. Evolution 18:596-608. Erwin, T. L. 1991. An evolutionary basis for conservation strategies. Science 253:750-752. Futuyama, D. J., and M. Slotkin, eds. 1983. Coevolution. Sunderland, Mass.: Sinauer Publishers. retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication aspublication this inserted.Please versionoftypographicerrors have been accidentallyretained, print and some use the may About PDFthis file: This new digital representation of original workthe has been recomposed XMLfrom files created from original the paper book, not from the original typesetting files. breaks Page are the true line lengths, word to original; breaks, heading styles, and other typesett

ion.

om Garey, J. F., R. M. Jordan, A. H. Aitken, D. T. Burton, and R. H. Gray, eds. 1980. Condenser r ibut f r Biofouling Control. Ann Arbor, Mich.: Ann Arbor Science Publishers. t cannot Geller, E. S. 1994, The human element in integrated environmental management. Pp. 5-26 in r at not

o Implementing Integrated Environmental Management, J. Cairns, Jr., T. V. Crawford, and f H. Salwassser, eds. Blacksburg, Va.: Virginia Polytechnic Institute and State University. Ghersa, C. M., M. L. Roush, S. R. Radosevich, and S. M. Cordray. 1994. Coevolution of however, agroecosystems and weed management. BioScience 44(2):85-94. version ng,

t Hammer, D. A., ed. 1989. Constructed Wetlands for Wastewater Treatment: Municipal, Industrial, paper book, at ive and Agricultural. Chelsea, Mich.: Lewis Publishers. at rm Harlan, J. R., and J. M. J. deWet. 1965. Some thoughts about weeds. Economic Botany 19:16-24. o

riginal Harte, J. 1993. The Green Fuse. Berkeley, Calif.: University of California Press. horit ic f

o Haskell, B. D., B. G. Norton, and R. Costanza. 1992. What is ecosystem health and why should we e

h worry about it? Pp. 3-19 in Ecosystem Health, New Goals for Environmental t he aut t

Management, R. Costanza and B. G. Norton, and B. D. Haskell, eds. Washington, D.C.: om r

as Island Press. ing-specif t Hayward, S. J., V. H. Gomez, and W. Sterrer. 1982. Bermuda's Delicate Balance. Hamilton: ion ed f Bermuda National Trust. peset

y Holling, C. S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics 4:1-24. publicat

her t Hughes, J. 1975. Ecology in Ancient Civilizations. Albuquerque: University of New Mexico Press. iles creat is

h Kauffman, S. A. 1991. Origins of Order: Self Organization and Selection in Evolution. New York: t L f Oxford University Press. M of

and ot

X Kauffman, S. A. 1993. The sciences of complexity and "origins of order." Annals of Earth 11 (3):19-26. om yles, r f Kew, H. W. 1893. The Dispersal of Shells. An Inquiry into the Means of Dispersal Possessed by st version Fresh-Water and Land Mollusca. London: Kegan Paul, Trench, Trubner and Co., Ltd. Kirch, P. V. 1984. The Evolution of Polynesian Chiefdoms. Cambridge, England: Cambridge print posed

e University Press. h

heading Ludyanskiy, M. L., D. McDonald, and D. MacNeill. 1993. Impact of the zebra mussel, a bivalve

recom invader. BioScience 43:533-544.

use t Martin, P. 1973. The discovery of America. Science 179:969-974.

breaks, Martin, P., and R. Klein. 1984. Quaternary Extinctions. Tucson: University of Arizona Press. ease l been Mosimann, J. E., and P. Martin. 1975. Simulating overkill by Paleoindians. American Scientist P 63:304-313. word has ed. Nalepa, T. F., and D. W. Schloesser. 1993. Zebra Mussels: Biology, Impacts, and Control. Ann hs, Arbor, Mich.: Lewis Publishers.

insert National Research Council. 1992. Restoring Aquatic Ecosystems: Science, Technology, and Public Policy. Washington, D.C.: National Academy Press. ally Ornstein, R., and P. Ehrlich. 1989. New World New Mind. New York: Simon and Schuster. line lengt

original work Platt, J. 1973. Social traps. American Psychology 28:642-651. e

h Pratt, J. R., and R. E. O'Connor. 1994. Public Involvement in Scoping for Environmental Impact t Assessment: A Case Study at Gettysburg National Military Park and Eisenhower National Historic Site. Technical Report NPS/MARO/NRTR-94 for the National Park Service. he original;

ion of Environmental Resources Research Institute, Pennsylvania State University, University t at o Park, PA. Quinn, D. 1992. Ishmael: A Novel. New York: Bantam/Turner Books. ue t r have been accident y

t Regier, H., and W. Hartman. 1973. Lake Erie's fish community: 150 years of cultural stresses. a Science 180:1248-1255. represent m are

l Rousseau, J.-J. 1754. Discours sur l'origine et les fondements de l'inegalite parmi les homme. 1983. a Discourse upon the Origin and Foundation of the Inequality Among Mankind. Translated errors

and edited by D. A. Cross. Indianapolis, Ind.: Hackett Publishing Co. Sachs, A. 1994. Men, sex, and parenthood in an overpopulating world. World Watch 7(2):12-19. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Samuels, M. L., and J L. Betancourt. 1982. Modeling the long-term effects of fuelwood harvests on r ibut f r pinyon-juniper woodlands. Environmental Management 6:505-515. t cannot Skinner, B. F. 1983. A Matter of Consequences, Part Three of an Autobiography. New York: Knopf. r at not

o Teger, A. I. 1980. Too Much Invested to Quit. New York: Pergamon Press. f Vitousek, P. M., P. R. Ehrlich, A. H. Ehrlich, and P. A. Matson. 1986. Human appropriation of the products of photosynthesis. BioScience 36:368-373. however, Vogl, R. J. 1980. The ecological factors that produce perturbation-dependent ecosystems. Pp. 63-94 version ng,

t in The Recovery Process in Damaged Ecosystems, J. Cairns, Jr., ed. Ann Arbor, Mich.: paper book, at ive Ann Arbor Science Publishers, Inc. at rm Wallace, B., J. Cairns, Jr., and P. A. Distler. 1993. Environmental Literacy and Beyond, President's o

riginal Symposium Volume V. Blacksburg: Virginia Polytechnic Institute and State University. horit ic f

o Wilson, E. O. 1988. Biodiversity. Washington, D.C.: National Academy Press. e

h Wingate, D. 1990. The restoration of Nonsuch Island as a living museum of Bermuda's precolonial t he aut t

terrestrial biome. Pp. 133-150 in The Earth in Transition, G. M. Woodwell, ed. New York: om r

as Cambridge University Press. ing-specif t Yoffee, N., and G. L. Cowgill, eds. 1988. The Collapse of Ancient States and Civilizations. Tucson: ion ed f University of Arizona Press. peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ENGINEERING RESILIENCE VERSUS ECOLOGICAL RESILIENCE 31 e h t be

ion. om r ibut f r t cannot r at not Engineering Resilience versus Ecological o f Resilience however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h C. S. Holling t he aut t

om r as ing-specif t ECOSYSTEM STRUCTURE AND FUNCTION ion ed f peset

y Ecological science has been shaped largely by the biological sciences.

publicat Environmental science, on the other hand, has been shaped largely by the her t iles creat is

h physical sciences and engineering. With the beginning of interdisciplinary t L f

M of efforts between the two fields, some of the fundamental differences between

and ot X them are generating conflicts caused more by misunderstanding of basic om yles, r

f concepts than by any difference in social purposes or methods. Those st version differences are most vivid in that part of ecology called ecosystem science, for

print it is there that it is obvious that both the biota and the physical environment posed e h

heading interact such that not only does the environment shape the biota but the biota

recom transforms the environment. use t The accumulated body of empirical evidence concerning natural, breaks, ease l been disturbed, and managed ecosystems identifies key features of ecosystem P structure and function (Holling et al., 1995) that probably are not included in word has ed.

hs, many engineers' image of ecology:

insert • Ecological change is not continuous and gradual; Rather it is episodic, with

ally slow accumulation of natural capital such as biomass or nutrients,

line lengt punctuated by sudden releases and reorganization of that capital as the original work e

h result of internal or external natural processes or of man-imposed t catastrophes. Rare events, such as hurricanes, or the arrival of invading

he original; species, can unpredictably shape structure at critical times or at locations of ion of t at o increased vulnerability. The results of these rare events can persist for long ue t r have been accident periods. Therein lies one of the sources of new options that biological y t a diversity provides. Irreversible or slowly reversible states exist—that is, represent m are

l once the system flips into such a state, only explicit management a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r intervention can return its previous self-sustaining state, and even then ibut f r t cannot success is not assured (Walker, 1981). Critical processes function at r at not

o radically different rates covering several orders of magnitude, and these f rates cluster around a few dominant frequencies.

however, • Spatial attributes are not uniform or scale invariant. Rather, productivity version ng,

t and textures are patchy and discontinuous at all scales from the leaf to the paper book, at ive individual, the vegetation patch, the landscape, and the planet. There are at rm o several different ranges of scales each with different attributes of patchiness riginal horit ic f

o and texture (Holling, 1992). Therefore scaling up from small to large e h cannot be a process of simple linear addition; nonlinear processes t he aut t organize the shift from one range of scales to another. Not only do the om r as ing-specif t large and slow variables control small and fast ones, the latter ion ed f occasionally "revolt" to affect the former. peset y • Ecosystems do not have single equilibria with functions controlled to publicat

her t remain near them. Rather, destabilizing forces far from equilibria, multiple iles creat is h t

L f equilibria, and disappearance of equilibria define functionally different

M of

and ot states, and movement between states maintains structure and diversity. On X the one hand, destabilizing forces are important in maintaining diversity, om yles, r f resilience, and opportunity. On the other hand, stabilizing forces are st version important in maintaining productivity and biogeochemical cycles, and even print posed

e when these features are perturbed, they recover rather rapidly if the h heading stability domain is not exceeded (e.g., recovery of lakes from recom

use t eutrophication or acidification, Schindler, 1990; Schindler et al., 1991). • Policies and management that apply fixed rules for achieving constant breaks, ease l been

P yields (such as constant carrying capacity of cattle or wildlife or constant

word

has sustainable yield of fish, wood, or water), independent of scale, lead to ed.

hs, systems that gradually lose resilience and suddenly break down in the face

insert of disturbances that previously could be absorbed (Holling, 1986).

ally Ecosystems are moving targets, with multiple potential futures that are line lengt uncertain and unpredictable. Therefore management has to be flexible, original work e h

t adaptive, and experimental at scales compatible with the scales of critical ecosystem functions (Walters, 1986). he original; ion of

t The features described above are the consequence of the stability at o properties of natural systems. In the ecological literature, these properties have ue t r have been accident

y been given focus through debates on the meaning and reality of the resilience of t a ecosystems. For that reason, and because the same debate seems to be emerging represent m are

a in economics, I will review the concepts to provide a foundation for errors

understanding. age breaks P is new digit THE TWO FACES OF RESILIENCE h pographic y iles. T t

e Resilience of a system has been defined in two different ways in the ile: ng i f t ecological literature. These differences in definition reflect which of two F

D different aspects of stability are emphasized. I first emphasized the P peset and som is y consequences of those different aspects for ecological systems to draw attention h t to the paradoxes between ined, a bout A ret original t

ion. om

r efficiency and persistence, or between constancy and change, or between ibut f r t cannot predictability and unpredictability (Holling, 1973). One definition focuses on r at not

o efficiency, constancy, and predictability—all attributes at the core of engineers' f desires for fail-safe design. The other focuses on persistence, change, and

however, unpredictability—all attributes embraced and celebrated by biologists with an version ng,

t evolutionary perspective and by those who search for safe-fail designs. paper book, at ive The first definition, and the more traditional, concentrates on stability near at rm o an equilibrium steady state, where resistance to disturbance and speed of return riginal horit ic f

o to the equilibrium are used to measure the property (O'Neill et al., 1986; Pimm, e h 1984; Tilman and Downing, 1994). That view provides one of the foundations t he aut t

om for economic theory as well and may be termed engineering resilience. r as ing-specif t The second definition emphasizes conditions far from any equilibrium ion ed f steady state, where instabilities can flip a system into another regime of behavior peset y —that is, to another stability domain (Holling, 1973). In this case the publicat

her t measurement of resilience is the magnitude of disturbance that can be absorbed iles creat is h t

L f before the system changes its structure by changing the variables and processes

M of

and ot that control behavior. We shall call this view ecological resilience (Walker et X al., 1969). om yles, r f The same differences have also begun to emerge in economics with the st version identification of multistable states for competing technologies because of print posed

e increasing returns to scale (Arthur, 1990). Thus, increasingly it seems that h heading effective and sustainable development of technology, resources, and ecosystems recom

use t requires ways to deal not only with near-equilibrium efficiency but with the reality of more than one equilibrium. If there is more than one equilibrium, in breaks, ease l been

P which direction should the finger on the invisible hand of Adam Smith point? If

word

has there is more than one objective function, where does the engineer search for ed.

hs, optimal designs?

insert These two aspects of a system's stability have very different consequences

ally for evaluating, understanding, and managing complexity and change. I argue line lengt that designing with ecosystems requires an emphasis on the second definition of original work e h

t resilience, that is, the amount of disturbance that can be sustained before a change in system control and structure occurs—ecological resilience. I do so he original;

ion of because that interplay between stabilizing and destabilizing properties is at the t at o heart of present issues of development and the environment—global change, ue t r have been accident biodiversity loss, ecosystem restoration, and sustainable development. y t a The two contrasting aspects of stability—essentially one that focuses on represent m are

l maintaining efficiency of function (engineering resilience) and one that focuses a on maintaining existence of function (ecological resilience)—are so errors fundamental that they can become alternative paradigms whose devotees reflect

age breaks traditions of a discipline or of an attitude more than of a reality of nature. P is new digit

h Those who emphasize the near-equilibrium definition of engineering pographic y iles. T t

f resilience, for example, draw predominantly from traditions of deductive e ile: ng i f mathematical theory (Pimm,. 1984) where simplified, untouched ecological t F

D systems are imagined, or from traditions of engineering, where the motive is to P peset and som is design systems y h t

ined, a bout A ret original t

ion. om

r with a single operating objective (DeAngelis, 1980; O'Neill et al., 1986; Waide ibut f r t cannot and Webster, 1976). On the one hand, that makes the mathematics more r at not

o tractable, and on the other, it accommodates the engineer's goal to develop f optimal designs. There is an implicit assumption of global stability, that is, that

however, only one equilibrium steady state exists, or, if other operating states exist, they version ng,

t should be avoided (Figure 1) by applying safeguards. paper book, at ive Those who emphasize the stability domain definition of resilience at rm o (ecological resilience), on the other hand, come from traditions of applied riginal horit ic f

o mathematics and applied resource ecology at the scale of ecosystems. Examples e h include the dynamics and management of freshwater systems (Fiering, 1982), of t he aut t

om forests (Holling et al., 1977), of fisheries (Waiters, 1986), of semiarid r as ing-specif t grasslands (Walker et al., 1969) and of interacting populations in nature (Dublin ion ed f et al., 1990; Sinclair et al., 1990). Because these studies are rooted in inductive peset y rather than deductive theory formation and in experience with the impacts of publicat

her t large-scale management disturbances, the reality of flips from one operating iles creat is h

t state to another cannot be avoided. Moreover, it becomes obvious that the L f

M of

and ot variability of critical variables forms and maintains the stability landscape X (Figure 2). om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t Figure 1 Two views of a single, globally stable equilibrium. (a) Provides a a represent m mechanical ball and topography analogy. (b) Provides an abstract state space are

a view of a point's movement toward the stable equilibrium, with x1 and x2

errors defining, for example, population densities of predator and prey, or of two

competitors. This is an example of engineering resilience. It is measured by the

age breaks resistance of the ball to disturbances away from the equilibrium point and the P is new digit speed of return to it. h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o FIGURE 2 Topographic analogy and state space views of evolving nature. The ue t r have been accident system modifies its own possible states as it changes over time from 1 to 4. In y t a this example, as time progresses, a progressively smaller perturbation is represent m are

l needed to change the equilibrium state of the system from one domain to the a other, until the system spontaneously changes state. (a) Ball and topography errors analogy. (b) Equivalent state space representation. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r MANAGING FOR ENGINEERING RESILIENCE ibut f r t cannot Management and resource exploitation can overload waters with nutrients, r at not o

f turn forests into grasslands, trigger collapses in fisheries, and transform savannas into shrub-dominated semideserts. One example, described by Walker however,

version et al. (1969) concerns grazing of semiarid grasslands. Under natural conditions ng,

i t paper book, at ive in east and south Africa, the grasslands were periodically pulsed by episodes of at rm intense grazing by various species of large herbivores. Directly as a result, a o riginal horit

ic f dynamic balance was maintained between two groups of grasses. One group o

e contains species able to withstand grazing pressure and drought because of their h t he aut

t deep roots. The other contains species that are more efficient in turning the sun's

om r as ing-specif energy into plant material, are more attractive to grazers, but are more t ion

ed f susceptible to drought because of the concentration of biomass above ground in peset

y photosynthetically active foliage. The latter, productive but drought-sensitive grasses, have a competitive publicat her t iles creat is edge between bouts of grazing so long as drought does not occur. But, because h t L f of pressure from pulses of intense grazing, that competitive edge for a time M of

and ot

X shifts to the drought-resistant group of species. As a result of these shifts in om yles,

r competitive advantage, a diversity of grass species serves a set of interrelated f st version functions— productivity on the one hand and drought protection on the other. When such grasslands are converted to cattle ranching, however, the cattle print posed e

h have been typically stocked at a sustained, moderate level, so that grazing shifts heading from the natural pattern of intense pulses separated by periods of recovery, to a recom use t more modest but persistent impact. Natural variability is replaced by constancy breaks,

ease of production. The result is that, in the absence of intense grazing, the l been P productive but drought-sensitive grasses consistently have advantage over the word has ed. drought-resistant species and the soil- and water-holding capacity they protect. hs, The land becomes more productive in the short-term, but the species insert assemblage narrows to emphasize one functional type. Droughts can no longer ally

line lengt be sustained and the system can suddenly flip to become dominated and original work

e controlled by woody shrubs. That is, ecological resilience is reduced. It is an h t

example of what Schindler (1990, 1993) has demonstrated experimentally in lakes as the effect of a reduction of species diversity when those species are part he original; ion of t

at of a critical ecosystem function. o There are many examples of managed ecosystems that share this same ue t r have been accident y t feature of gradual loss of functional diversity with an attendant loss of resilience a represent m

are followed by a shift into an irreversible state, such as occurs in agriculture and in

l a forest, fish, and grasslands management (as summarized in Holling, 1986). In errors each case the cause is reduction of natural variability of the critical structuring variables such as plants, insect pests, forest fires, fish populations, or grazing age breaks

P pressure to achieve a social, economic, or engineering objective. The result is is new digit h pographic that the ecosystem evolves to become more spatially uniform, less functionally y iles. T t

f e

ile: diverse, and more sensitive to disturbances that otherwise could have been ng i f t

F absorbed. D P peset and som is y h t

ined, a bout A ret original t

ion. om

r That is, ecological resilience decreases even though engineering resilience ibut f r t cannot might be great. Short-term success in stabilizing production leads to long-term r at not

o surprise. f Moreover, such changes can be essentially irreversible because of

however, accompanying changes in soils, hydrology, disturbance processes, and species version ng,

t complexes that regulate or control ecological structure and dynamics. Control paper book, at ive of ecosystem function shifts from one set of interacting physical and biological at rm o processes to a different set (Holling et al., 1995). riginal horit ic f

o In the examples of resource management that I have explored in depth, not e h only do ecosystems become less resilient when they are managed with the goal t he aut t

om of achieving constancy of production, but the management agencies, in their r as ing-specif t chive for efficiency, also become more myopic, the relevant industries become ion ed f more dependent and static, and the public loses trust (Gunderson et al., 1995). peset y This seems to define an ultimate pathology that typically can lead to a crisis publicat

her t triggered by unexpected external events, sometimes followed by a reformation iles creat is h

t of policy. I first saw the form of this pathology emerging in the early stages of L f

M of

and ot testing and developing theories, methods, and case study examples of adaptive X environmental assessment and management. Those cases and their diagnoses om yles, r f were summarized in Holling (1986). st version Those cases involved a number of different examples of forest print posed

e development, fisheries exploitation, semiarid grazing systems, and disease h heading management in crops and people. We have greatly expanded and deepened the recom

use t case studies and tests since then, adding examples that are presented in a new book that explores both the dynamics of ecosystems and the dynamics of the breaks, ease l been

P institutions that attempt to manage them (Gunderson et al., 1995). Two of the

word

has original examples continue to provide insights. ed.

hs, In those two examples, the initial diagnoses of the pathology as I saw it in

insert the early 1970s were as follows:

ally • Successful suppression of spruce budworm populations during the 1950s line lengt

original work and 1960s in eastern Canada, using insecticide, certainly preserved the pulp e h t

and paper industry in the short-term by significantly reducing defoliation by the insect so that tree mortality was delayed. This encouraged expansion he original; ion of

t of pulp mills but left the forest, and hence the economy, more vulnerable to at o an outbreak that would cause more intense and more extensive tree ue t r have been accident

y mortality than had ever been experienced before. That is, the short-term t a success of spraying led to moderate levels of infestation and partially represent m are

a protected foliage that became more homogeneous over larger areas, errors

demanding ever more vigilance and control. • Effective protection and enhancement of salmon spawning through use of

age breaks fish hatcheries on the west coast of North America quickly led to more P is new digit h

pographic predictable and larger catches by both sport and commercial fishermen. y iles. T t

e That triggered increased fishing pressure and investment in both sectors, ile: ng i f t pressure that caused more and more of the less productive natural stocks to F

D become locally extinct. P peset and som is y h t

ined, a bout A ret original t

ion. om

r That left the fishing industry precariously dependent on a few artificially ibut f r t cannot enhanced stocks, whose productivity began declining in a system where larger- r at not

o scale physical oceanic changes contributed to unexpected impacts on the f distribution and abundance of fish.

however, In both those cases, however, by the 1980s I began to realize that the phase version ng,

t of a growing pathology was transient and could be broken by a spasmodic paper book, at ive readjustment, an adaptive lurch of learning that created new opportunity. It is at rm o that creation of something fundamentally novel that gives an evolutionary riginal horit ic f

o character to development of a region that might make sustainable development e h an achievable reality rather than an oxymoron. t he aut t

om The heart of these two different views of resilience lies in assumptions r as ing-specif t regarding whether multistable states exist. If it is assumed that only one stable ion ed f state exists or can be designed to so exist, then the only possible definitions for, peset y and measures of, resilience are near-equilibrium ones—such as characteristic publicat

her t return time. Prod that is certainly consistent with the engineer's desire to make iles creat is h

t things work, not to make things that break down or suddenly shift their L f

M of

and ot behavior. But nature is different. X There are different stability domains in nature, and variation in critical om yles, r f variables tests the limits of those domains. Thus, a near-equilibrium focus st version seems myopic and attention shifts to determining the constructive role of print posed

e instability in maintaining diversity and persistence and to designs of h heading management that maintain ecosystem function in the face of unexpected recom

use t disturbances. Such designs would maintain or expand ecological resilience. It is those ecosystem functions and ecological resilience that provide the ecological breaks, ease l been

P ''services'' that invisibly provide the foundations for sustaining economic activity.

word has ed. hs, MANAGING FOR ECOLOGICAL RESILIENCE insert

ally There is a puzzle in these examples and this analysis. It implies that line lengt efficient control and management of renewable resources in an engineering original work e h

t sense leads initially to success in managing a target variable for sustained production of food or fiber but ultimately to a pathology of less resilient and he original;

ion of more vulnerable ecosystems, more rigid and unresponsive management t at o agencies, and more dependent societies. But there seems to be something ue t r have been accident inherently wrong with that conclusion, implying, as it does, that the only y t a solution is humanity's radical return to being "children of nature." The puzzle represent m are

l needs to be clarified to test its significance and generality. a The above conclusion is based on two critical points. One is that reducing errors the variability of critical variables within ecosystems inevitably leads to reduced

age breaks resilience and increased vulnerability. The second is that there is, in principle, P is new digit

h no different way for agencies and people to manage and benefit from resource pographic y iles. T t

f development. Both points are explored in more detail in a new book on barriers e ile: ng i f and t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r bridges to ecosystem and institutional renewal (Gunderson et al., 1995), so here ibut f r t cannot I will deal only with highlights. r at not

o Puzzles can sometimes be solved by searching for counterexamples. f Oddly, nature itself provides such counterexamples of tightly regulated yet

however, sustainable systems in the many examples of physiological homeostasis. version ng,

t Consider temperature regulation of endotherms (warm-blooded animals). The paper book, at ive internal body temperature of endotherms is not only tightly regulated within a at rm o narrow band, but among present-day birds and mammals, the average riginal horit ic f

o temperature is perilously close to lethal. Moreover, the cost of achieving that e h regulation requires ten times the energy for metabolism that is required by t he aut t ectotherms (cold-blooded animals). That would seem to be a recipe for not only om r as ing-specif t disaster but a very inefficient one at that. And yet evolution somehow led to the ion ed f extraordinary success of the animals having such an adaptation—the birds and peset y mammals. publicat

her t To test the generality of the variability-loss/resilience-loss hypothesis, I iles creat is h t

L f have been collecting data from the physiological literature on the viable

M of

and ot temperature range within the bodies of organisms exposed to different classes X of variability. I have organized the data into three groups ranging from om yles, r f terrestrial ectotherms, which are exposed to the greatest variability of st version temperature from unbuffered ambient conditions, to aquatic ectotherms, which print posed

e are exposed to an intermediate level of variability because of the moderating h heading attributes of water, to endotherms, which regulate temperature within a narrow recom

use t band. The viable range of internal body temperature decreases from about 40 degrees centigrade for the most variable group to about 30 degrees for the breaks, ease l been

P intermediate, to 20 degrees for the tightly regulated endotherms. Therefore

word

has resilience, in this case the range of internal temperatures that separates life from ed.

hs, death, clearly does contract as variability in internal temperature is reduced, just

insert as in the resource management cases. I conclude, therefore, that reduction of

ally variability of living systems, from organisms to ecosystems, inevitably leads to line lengt loss of resilience in that part of the system being regulated. original work e h

t But that seems to leave an even starker paradox for management; seemingly successful control inevitably leads to collapse. But, in fact, he original;

ion of endothermy does persist and flourish. It therefore serves as a revealing t at o metaphor for sustainable development. This metaphor contains two features that ue t r have been accident were not evident in my earlier descriptions of examples of resource management. y t a First, the kind of regulation is different. Five different mechanisms, from represent m are

l evaporative cooling to metabolic heat generation, control the temperature of a endotherms. Each mechanism is not notably efficient by itself. Each operates errors over a somewhat different but overlapping range of conditions and with

age breaks different efficiencies of response. It is this overlapping "soft" redundancy that P is new digit

h seems to characterize biological regulation of all kinds. It is not notably pographic y iles. T t

f efficient or elegant in the engineering sense. But it is robust and continually e ile: ng i f sensitive to changes in internal body temperature. That is quite unlike the t F

D examples of rigid P peset and som is y h t

ined, a bout A ret original t

ion. om

r regulation by management where goals of operational efficiency gradually ibut f r t cannot isolated the regulating agency from the things it was regulating. r at not

o Examples of similar regulation of ecosystem dynamics in nature include f the set of herbivorous antelope species that structure the vegetation of the

however, savannas of East Africa at intermediate scales from meters to kilometers version ng,

t (Walker et al., 1969) or the suite of 35 species of insectivorous birds that, paper book, at ive through their predation on insect larvae, set the timing for outbreaks of spruce at rm o budworm in the forests of eastern Canada (Holling, 1988). In these examples, riginal horit ic f

o each species performs its actions somewhat differently from others, and each e h responds differently to external variability because of differences in habitat t he aut t preference and the scales of choice for its resources (Holling, 1992). As an om r as ing-specif t example, some species of insectivorous birds exert modest predation pressure ion ed f over a broad range of prey densities, whereas others exert strong pressure over peset y narrow ranges of density and still others function between those extremes. The publicat

her t densities at which the predation impact is maximal also differ between species. iles creat is h

t Competition occurs among these species such that the aggregate predation L f

M of

and ot effect is inefficient when predators are abundant and prey scarce and efficient X when the reverse is true. As a consequence, the result of their joint action is an om yles, r f overlapping set of reinforcing influences that are less like the redundancy of st version engineered devices and more like portfolio diversity strategies of investors. The print posed

e risks and benefits are spread widely to retain overall consistency in performance h heading independent of wide fluctuations in the individual species. That is at the heart of recom

use t the role of functional diversity in maintaining the resilience of ecosystem structure and function. breaks, ease l been

P We chose the term functional diversity to describe this process, following

word

has the terms suggested by Schindler (1990) and by Holling et al. (1995). Such ed.

hs, diversity provides great robustness to the process and, as a consequence, great

insert resilience to the system behavior.

ally The second feature of nature's way of tightly regulating variability that is line lengt different from traditional management is the tendency to function near the edge original work e h

t of instabilities, not far away from them. That is where information and opportunity are the greatest. Again endothermy provides an example. he original;

ion of Endothermy is a true innovation that explosively released opportunity for the t at o organisms that evolved the ability to regulate their body temperature. ue t r have been accident Maintaining high body temperature, just short of death, allows the greatest y t a range of external activity for an animal. Speed and stamina increase and activity represent m are

l can be maintained at both high and low external temperatures. A range of a habitats forbidden to an ectotherm is open to an endotherm. The evolutionary errors consequence of temperature regulation was to open opportunity suddenly for

age breaks dramatic organizational change and the adaptive radiation of new life forms. P is new digit

h Variability is therefore not eliminated. It is reduced in one place and transferred pographic y iles. T t

from the animal's internal environment to its external environment as a f e ile: ng i f consequence of allowing continual probes by the whole animal for opportunity t F

D and change. Hence the price of reducing internal resilience, maintaining high P peset and som

is metabolic levels, and operating y h t

ined, a bout A ret original t

ion. om

r dose to an edge of instability is more than offset by that creation of evolutionary ibut f r t cannot opportunity. Nature's policy of ecological resilience, if we can call it that, seems r at not

o far from those of traditional engineering safeguards or economic efficiency, f where operating near an equilibrium far from an instability defines engineering

however, resilience. version ng,

t But ascribing that designation to engineering is to stereotype the field with paper book, at ive only one face of its activities, just as ecological resilience represents only one at rm o face of ecology. At least some aspects of ecologically resilient control are riginal horit ic f

o equally familiar to the control engineer, for operation at the edge of instability is e h characteristic of designs for high-performance aircraft. Oddly, the result is t he aut t

om opportunity. Effective control of internal dynamics at the edge of instability r as ing-specif t generates external options. Operating at the edge of instability generates ion ed f immediate signals of changing opportunity. peset y That surely is at the heart of sustainable development—the release of publicat

her t human opportunity. It requires flexible, diverse, and redundant regulation, early iles creat is h t

L f signals of error built into incentives for corrective action, and continuous

M of

and ot experimental probing of the changes in the external world. Those are the X features of adaptive environmental and resource management. Those are the om yles, r f features missing in the descriptions I presented of traditional, piecemeal, st version exploitive resource management and its ultimate pathology. print posed e h heading CONCLUSION recom use t There are indeed strong suggestions that management and institutional breaks, ease l been

P regimes can be designed to preserve or expand resilience of systems as well as

word

has provide developmental opportunity. It is a central issue that only now is ed.

hs, beginning to be the focus of serious scholarship and practice. Of the cases I

insert know well, management of the forests of New Brunswick seems most clearly to

ally demonstrate the cycles of crisis and learning and the hesitant emergence of a line lengt more sustainable path. original work e h

t In the New Brunswick example, one major crisis and several minor ones have occurred since the early 1950s. During this period, the new technologies of he original;

ion of airplanes and pesticides developed in World War II were adapted for spraying t at o operations and their use was progressively refined to achieve high mortality of ue t r have been accident insects while reducing environmental side effects. These procedures for y t a pesticide control of budworm synergized with other technological developments represent m are

l in tree harvesting, pulp production chemistry, and mill construction and resulted a in large investments in pulp production. Minor crises occurred when effects on errors human health were linked to the pesticides. Key pieces of integrated

age breaks understanding of the natural system were achieved by the teams of Morals P is new digit

h (1963) and the modelers of the 1970s (Clark et al., 1979). The brittleness that pographic y iles. T t

developed (defined by a loss of ecological resilience together with an increase f e ile: ng i f in institutional efforts to control information and action) reflected the t F

D complacent belief among P peset and som is y h t

ined, a bout A ret original t

ion. om

r agency staffs that budworm damage was controlled in an efficient and cost- ibut f r t cannot effective manner and that there was plenty of wood available for harvest. In r at not

o reality, the costs of using pesticides were rapidly increasing because of f increases in oil prices and because of modification of pesticide application in

however, response to public pressure. In addition, available stocks of harvestable trees version ng,

t were decreasing because of past harvests and because more and more mature paper book, at ive stands over larger areas were gradually deteriorating from the pressure of at rm o moderate but persistent budworm defoliation. The major crises occurred during riginal horit ic f

o the late 1970s when a forest inventory report finally indicated that there would e h not be sufficient stock to support the current mills, thereby confirming an earlier t he aut t prediction of the models. This led to a new law that restructured the licensing om r as ing-specif t and forest management policies and freed the innovative capacity of local ion ed f industries within a regional set of goals and constraints. A sequence of adaptive peset y responses among the actors began to develop regional forest policy in a way publicat

her t that now engages local industrial, environmental, and recreational goals. iles creat is h t

L f The examples of growing pathology are caused by the very success of

M of

and ot achieving near equilibrium behavior and control of a single target variable X independently of the larger ecosystem, economic, and social interactions. When om yles, r f that orientation or goal is abandoned, it happens suddenly, in response to st version perceived or real crises. The scale of the issues becomes redefined more broadly print posed

e from a local to a regional setting and from short-term to long-term. The h heading scientific understanding of the natural system becomes more integrated, and the recom

use t issues themselves are not posed in response to needs to maximize constancy or productivity of yield, but to ones of designing interrelations between people and breaks, ease l been

P resources that are sustainable in the face of surprises and the unexpected. If

word

has there is such a thing as sustainable development, then that is it. The key features ed.

hs, are integration of knowledge at a range of scales, engagement of the public in

insert exploring alternative potential futures, adaptive designs that acknowledge and

ally test the unknown, and involvement of citizens in monitoring and understanding line lengt outcomes. That is possible only in situations where ecological resilience and original work e h

t public trust have not been degraded. If they have, as in many situations, then the initial goal has to be the restoration of both resilience and trust. he original; ion of t at o REFERENCES ue t r have been accident y t

a Arthur, B. 1990. Positive feedback in the economy. Scientific American 262:92-99. represent m

are Clark, W. C., D. D. Jones, and C. S. Holling. 1979. Lessons for ecological policy design: A case

a study of ecosystem management. Ecological Modeling 7:1-53. DeAngelis, D.L. 1980. Energy flow, nutrient cycling and ecosystem resilience. Ecology 61:764-771. errors Dublin, H. T., A. R. E. Sinclair, and J. MeGlade. 1990. Elephants and fire as causes of multiple stable states in the Serengeti-mara woodlands. Journal of Animal Ecology 59:1147-1164. age breaks Fiering, M.B. 1982. Alternative indices of resilience. Water Resources Research 18:33-39. P is new digit

h Gunderson, L. H., C. S. Holling, and S. Light. 1995. Barriers and Bridges to Renewal of Ecosystems pographic y iles. T t and Institutions. New York: Columbia University Press.

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Holling, C.S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and r ibut f r Systematics 4:1-23. t cannot Holling, C. S. 1986. Resilience of ecosystems; local surprise and global change. Pp. 292-317 in r at not

o Sustainable Development of the Biosphere, W. C. Clark and R. E. Munn, eds. Cambridge, f England: Cambridge University Press. Holling, C. S. 1988. Temperate forest insect outbreaks, tropical deforestation and migratory birds . however, Memoirs of the Entomological Society of Canada 146:21-32. version ng,

t Holling, C.S. 1992. Cross-scale morphology, geometry and dynamics of ecosystems. Ecological paper book, at ive Monographs 62(4):447-502. at rm Holling, C. S., D. D. Jones, and W. C. Clark. 1977. Ecological policy design: A case study of forest o

riginal and pest management. IIASA CP-77-6:13-90 in Proceedings of a Conference on Pest horit ic f

o Management, October 1976, G. A. Norton and C. S. Holling, eds. Laxenburg, Austria. e

h Holling, C. S., D. W. Schindler, B. Walker, and J. Roughgarden. 1995. Biodiversity in the t he aut t

functioning of ecosystems: An ecological primer and synthesis. In Biodiversity Loss: om r

as Ecological and Economic Issues, C. Perrings, K-G Mäer, C. Folke, C. S. Holling, and B-O ing-specif t Jansson, eds. Cambridge, England: Cambridge University Press. ion ed f Morris, R. F. 1963. The dynamics of epidemic spruce budworm populations. Memoirs of the peset

y Entomological Society of Canada 21:332. O'Neill, R. V., D. L. DeAngelis, J. B. Waide, and T. F. H. Allen. 1986. A Hierarchical Concept of publicat

her t Ecosystems. Princeton, N.J.: Princeton University Press . iles creat is

h Pimm, S.L. 1984. The complexity and stability of ecosystems. Nature 307:321-326. t L f Schindler, D.W. 1990. Experimental perturbations of whole lakes as tests of hypotheses concerning M of

and ot

X ecosystem structure and function. Proceedings of 1987 Crafoord Symposium. Oikos 57:25-41. om yles, r f Schindler, D.W. 1993. Linking species and communities to ecosystem management. Proceedings of st version the 5th Cary Conference, May 1993. Schindler, D. W., T. M. Frost, K. H. Mills, P.S.S. Chang, I. J. Davis, F. L. Findlay, D. F. Malley, J. print posed

e A. Shearer, M. A. Turner, P. J. Garrison, C. J. Watras, K. Webster, J. M. Gunn, P. L. h

heading Brezonik, and W. A. Swenson. 1991. Freshwater acidification, reversibility and recovery:

recom Comparisons of experimental and atmospherically-acidified lakes. Volume 97B: 193-226

use t in Acidic Deposition: Its Nature and Impacts, F. T. Last and R. Watling, eds. Proceedings

breaks, of the Royal Society of Edinburgh. ease l been Sinclair, A. R. E., P. D. Olsen, and T. D. Redhead. 1990. Can predators regulate small mammal P populations? Evidence from house mouse outbreaks in Australia. Oikos 59:382-392. word has ed. Tilman, D., and J. A. Downing. 1994. Biodiversity and stability in grasslands. Nature 367:363-365. hs, Waide, J. B., and J. R. Webster. 1976. Engineering systems analysis: Applicability to ecosystems.

insert Volume IV, pp. 329-371 in Systems Analysis and Simulation in Ecology, B.C. Patten, ed. New York: Academic Press. ally Walker, B.H. 1981. Is succession a viable concept in African savanna ecosystems? Pp. 431-447 in line lengt

original work Forest Succession: Concepts and Application, D.C. West, H. H. Shugart, and D. B. Botkin, e

h eds. New York: Springer-Verlag. t Walker, B. H., D. Ludwig, C. S. Holling, and R. M. Peterman. 1969. Stability of semi-arid savanna grazing systems. Ecology 69:473-498. he original;

ion of Walters, C.J. 1986. Adaptive Management of Renewable Resources. New York: McGraw Hill. t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not A Scalar Approach to Ecological o f Constraints however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Bryan G. Norton t he aut t

om r as ing-specif t ENVIRONMENTAL PROBLEMS IN PERSPECTIVE ion ed f peset

y Environmental problems arc basically problems of scale. This is especially

publicat true of environmental problems that involve ecological constraints as important her t iles creat is

h elements. This chapter considers scale in a broad social sense. In particular, it t L f

M of examines the effect of social values on the scale at which we experience the

and ot X world; conversely, it explores the role of objective determinations of scale in om yles, r

f shaping social values. These two aspects of scale apparently represent a st version complex and highly interactive dynamic. We can think of these interactions as

print posing problems in the phenomenology of space—the study of space as posed e h

heading experienced, which is itself an important, if somewhat neglected, branch of

recom geography (Seamon and Mugerauer, 1989; Tuan, 1971, 1977). This approach use t emphasizes sense of place values and sentiments, recognizing that all people breaks, ease l been value objects from a particular perspective; further, the scale of space that P people perceive as their sphere of action imposes a shape on their consciousness word has ed.

hs, and their valuations. The "objective" concept of space that is favored in the modernist, insert Newtonian perspective has fallen on bad times in this century; in the ally

line lengt postmodernist period, time and space have been relativized and complexified in original work

e ways that could not be imagined within the Newtonian tradition (Prigogene and h t Stengers, 1984). Our conceptions of space and time are undergoing rapid flux as it has become clear that one cannot think of space as a unified, continuous he original; ion of t at o plenum on which events can be unambiguously located. It turns out, on the

ue t contrary, that there are many— possibly incommensurable—correct r have been accident y t

a characterizations of spatial relationships, depending on the perspective specified represent m are

and the scale chosen. The world as described from the viewpoint of a mite that l a lives on a beetle differs fundamentally errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r from a description of the world as viewed by large-bodied mammals such as ibut f r t cannot ourselves. If our descriptions of multiscalar natural systems inevitably involve a r at not

o choice regarding the perspective from which, and scale on which, to measure f and monitor natural systems, how can we avoid the apparent implication that

however, our human values and perspectives may influence the scales we observe and version ng,

t describe in nature? If this implication is accepted, it seems also to follow that paper book, at ive the "descriptive" models we use to characterize natural processes actually at rm o express, in a less explicit but nevertheless profound sense, the values we pursue riginal horit ic f

o and the actions we take in pursuing them. e h While a full exploration of this less objectivist approach to scale would be t he aut t

om beyond the scope of this paper, these general ideas set the background for the r as ing-specif t more particular explorations undertaken here. I believe that conservation ion ed f biology, restoration ecology, and ecological engineering are all "normative peset y sciences" and that choices of models to understand interactions between humans publicat

her t and nature are either explicitly or implicitly based on value considerations. One iles creat is h

t of the important ways—perhaps the most important way—in which values L f

M of

and ot affect science is in our choice of scales on which to characterize and address X ecological risks and problems. For this reason I undertake, with some om yles, r f trepidation, an examination of scalar aspects of human values as my st version contribution to the discussions of engineering and ecological constraints central print posed

e to this volume. h heading This paper addresses three important aspects of scalar problems in recom

use t environmental values and policy. First, I explore the idea that the nonnative disciplines of conservation biology, restoration ecology, and ecological breaks, ease l been

P engineering use a "scientific" language that must have normative as well as

word

has descriptive content. Further, I believe that this valuational element is often ed.

hs, embodied in decisions regarding the scale we choose to employ and the scale of

insert the models we construct in our observation and manipulation of our

ally environment. Second, building on empirical and theoretical work by Holling line lengt (1978, 1992, 1994, and in this volume), I propose a multiscalar analysis of original work e h

t social values and argue for a pluralistic approach to environmental policy. This approach recognizes multiple, irreducible values derived from nature by he original;

ion of humans, seeks to associate particular values and classes of values with specific t at o natural dynamics that are dominant on various scales of the environment, and ue t r have been accident organizes human values according to scale, providing multiple criteria of good y t a management guided by multiple values. Finally, I will offer a series of devices represent m are

l called risk decision squares, which help to sort decisions affecting the a environment according to an ecologically—that is, spatially and temporally— errors sensitive typology of risks involved in a given decision. age breaks P is new digit h pographic

y ENVIRONMENTAL PROBLEMS AS SCALAR PROBLEMS iles. T t

f e ile: ng i f One important consequence of the rise of modernism and the Newtonian, t F

D objectivist model of the physical universe is that choices of scale and P peset and som is perspective become an essential element in every description of nature. y h t

Observation is necessarily ined, a bout A ret original t

ion. om

r from some place, and the relevant scale must be specified. These general ibut f r t cannot conclusions follow from relativity theory (Prigogene and Stengers, 1984). But r at not

o ecological processes, especially, can also be described on countless alternative f scales (Levin, 1992). How do we know the scale on which to model an

however, environmental "problem" and measure our progress toward solving it? Pure version ng,

t ecology cannot be the only guide because the descriptions of nature it provides paper book, at ive are too numerous and also incommensurate because of the differing scales they at rm o embody. An important goal of environmental ethicists and policy analysts riginal horit ic f

o should therefore be to ascertain which natural dynamics are associated with e h important social values. What is needed is a more encompassing, t he aut t interdisciplinary discussion of environmental values and goals. Of course such a om r as ing-specif t discussion must be based on the best science, but establishing crucial links ion ed f between ecological processes and environmental policy can be understood only peset y in conjunction with a process of articulating important social values. In the publicat

her t process, the boundary between theoretical ecology and applied disciplines, such iles creat is h

t as restoration ecology and ecological engineering, will no doubt be blurred. L f

M of

and ot Determining which dynamics require special protection is an evaluative X task that can only be done from a perspective; and identifying scales and om yles, r f bifurcation points is on this view a crucial aspect of management. All of this is st version part of defining what is a healthy system and when a system maintains its

print 1 posed

e integrity. Scale is at the heart of all these problems, but we cannot choose h heading appropriate scales to focus on until we understand both how ecological recom

use t functions and processes work at various levels and how these functions and processes are associated with social values. Fully understanding this point will breaks, ease l been

P require that we reconsider the assumptions of "value-neutral science." In the

word

has modern, Cartesian-Newtonian period, and especially in the positivist era of ed.

hs, science since 1900, description and evaluation have been regarded as separable

insert steps in the process of understanding and acting in nature. It has been thought

ally that natural systems and their products can first be described and that line lengt evaluations can then be applied to these "objective" descriptions as a separable original work e h

t step in the process of judgment and choice of actions. What we know now is that our choice of descriptive concepts shapes our perceptions (Kuhn, 1962; he original;

ion of Quine, 1960). Even more important, conceptual and theoretical choices are t at o colored by our values because we choose our theories in the process of ue t r have been accident accomplishing conscious or unconscious goals through action. y t a The recognition that some of our concepts embody both factual and represent m are

l evaluative content is really only a special case of a much more general a phenomenon— description and prescription are so entwined in our use of errors language that it is often impossible to separate them in ordinary discourse

age breaks (Nelson, 1995; Williams, 1985). This interpenetration of values and facts in P is new digit

h ordinary discourse can be cited as one of the reasons scientific disciplines create pographic y iles. T t

more precise vocabularies; but, however useful an introduced special f e ile: ng i f vocabulary, such formalistic languages cannot ultimately achieve pure t F

D description and at the same time be rich enough to guide P peset and som is y h t

ined, a bout A ret original t

ion. om

r behavior, as Nelson argues. Every choice of a vocabulary to describe nature ibut f r t cannot requires an exclusion of other facets of reality. Every choice to measure features r at not

o x or y involves a choice not to measure some other features, w and z. Languages f are in this sense more like spotlights than floodlights (Norton, 1991). They

however, highlight certain aspects of our experience and push other aspects into the version ng,

t unmeasured shadows. Thus, while measurements of aspects of nature might be paper book, at ive carried out with precision and "objectivity," the choice to measure one aspect at rm o and ignore others nevertheless reflects an implicit or explicit evaluation of the riginal horit ic f

o comparative importance of the aspects. e h In this sense, the emergence of an ecological approach to environmental t he aut t

om management embodies a shift in language and hence a resolution to pay r as ing-specif t attention to different aspects of nature as we examine management options. ion ed f Because nature is irreducibly complex and there exist countless correct peset y descriptions of nature, we focus on only a few of these as helpful in deciding publicat

her t how to live. These choices to focus on a particular dynamic to measure involve, iles creat is h

t however subtly, value judgments, which are embodied in our decisions L f

M of

and ot regarding what variables to monitor. Let us begin our exploration of values X implicit in scalar decisions with a well-known example—attempts to protect the om yles, r f Chesapeake Bay—that will illustrate how social values and physical scale st version interact in the formulation and response to an environmental problem. In the print posed

e 1960s, a number of observers declared that unhealthy changes were taking place h heading in Chesapeake Bay. Early alarms were expressed in many different recom

use t vocabularies. One state legislator, for example, decried the fact that he could no longer see his toes when standing in waist-deep water (Horton, 1987). These breaks, ease l been

P varied expressions of concern did not yet amount to a well-formulated

word

has environmental problem because the problems of bay water quality had not yet ed.

hs, been characterized and modeled with sufficient precision to allow a description

insert and evaluation of changing trends. In the wake of a major U.S. Environmental

ally Protection Agency study (1983), public and scientific opinion united behind a line lengt "model" of the problem of bay water quality as affected by nutrient loading original work e h

t from stationary and nonpoint sources. In the course of focusing on the processes affecting bay water quality, an important scalar, boundary issue was also he original;

ion of resolved: management attention moved from the bay stem and tributaries to the t at o widespread lands that form the watershed. The formulation of the "problem" ue t r have been accident with the Chesapeake involved important choices about what processes were y t a crucial for defending social values, as well as scientific attempts to measure and represent m are

l monitor those important processes. a While this example represents a complex process of problem articulation errors in simplified form, it illustrates how a society, by focusing on certain trends as

age breaks environmental problems, implicitly builds important value judgments into its P is new digit

h choice of scales. The complex process of formulating environmental problems pographic y iles. T t

f is diagrammed in Figure 1. The triangle must embody both evaluative and e ile: ng i f empirical inputs. The horizontal bar represents the point at which a full-blown t F

D environmental problem can be addressed. P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t FIGURE 1 The environmental policy process. Environmental problems are not

he original; clearly formulated when they first emerge in public discourse. Determination ion of t at o of the proper scale at which a problem should be ''modeled'' requires an interactive, public process in which public values guide scientific development ue t r have been accident y t of models. Once the problem is precisely defined and models developed, the a represent m

are process of experimentation with solutions can begin. Source: Reproduced from

a Norton and Ulanowicz (1992) by permission of Amnbio. errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Consider another, even more schematic, "environmental problem"— ibut f r t cannot Garrett Hardin's tragedy of the commons (1968). Hardin's parable, while r at not

o introduced as applicable to human reproductive decisions and human f population, is remarkable in its broad applicability to virtually every

however, environmental problem. Hardin's parable achieves such generality because version ng,

t environmental quality is so often a public good that must be achieved in spite of paper book, at ive individual interest, rather than because of it. No matter how large a finite at rm o commons, the unfettered exercise of individual, self-oriented values will lead riginal horit ic f

o eventually to its destruction; as the "herd" is expanded by individual choice, the e h individual-scale decisions will add up to a total effect too great for the carrying t he aut t capacity of the commons. Individuals, motivated by short-term profits, will not om r as ing-specif t adequately consider the longer-term consequences of their actions, because ion ed f these are delayed and diffused throughout the community—they exist on peset y another scale in time and space. Unless individual action is limited by mutually publicat

her t agreed-upon constraint, the public interest will be destroyed by individual iles creat is h

t choices. Hardin's scenario is our scenario, because we are at that point in L f

M of

and ot history at which human population and industrial growth are approaching or X surpassing the carrying capacities of many systems. In this unprecedented om yles, r f situation, even the functioning of ecosystems essential to regional economies st version and communities become public goods. They represent resources that cannot be print posed

e owned—they are available to everyone if they are available to anyone—and h heading they can be destroyed by aggregate action in which each individual actor seeks recom

use t his or her self-interest exclusively. Hardin's parable, by modeling environmental problems as community-scale problems resulting from individually motivated breaks, ease l been decisions, therefore illustrates in general terms how environmental problems are P

word

has most basically problems of scale. ed. hs,

insert HOLLING'S WORLD ally

line lengt Recent groundbreaking work by Holling has hypothesized, and provided original work e h

t significant empirical evidence, that the dynamics of natural systems "are controlled and organized by a small set of key plant, animal, and abiotic he original;

ion of processes." He further argues that "the geometry of landscapes and ecosystems t at o is organized into a small number of quanta with distinct architectural attributes," ue t r have been accident attributes that are especially relevant from a human perspective (Holling, 1992, y t a p. 449; also see Allen and Starr, 1982; Norton and Ulanowicz, 1992; O'Neill et represent m are

l al., 1986). a Holling's work supports, both theoretically and empirically, a broadly errors hierarchical approach to understanding physical and ecological processes,

age breaks suggesting that the human tendency to understand complex systems P is new digit

h hierarchically (noted by Allen and Hoekstra, 1992; Allen and Starr, 1982) is not pographic y iles. T t

f adventitious. It is a structural aspect of natural systems as they are experienced e ile: ng i f by human observers. Indeed, Holling's evidence suggests that all mammals of t F

D roughly human body size must perceive the world as organized according to P peset and som is similar scalar properties. Holling concludes that "The landscape is structured y h t

hierarchically by a small ined, a bout A ret original t

ion. om

r number of structuring processes into a small number of levels, each ibut f r t cannot characterized by a distinct scale of 'architectural' texture and of temporal speed r at not

o of variables" (Holling, 1992, p. 484). This hypothesis, if verified by further f research, may have important consequences for the way we think about

however, environmental values as well. Holling's model suggests (a) that environmental version ng,

t values are shaped, perhaps even genetically, within an architecturally structured paper book, at ive natural world; (b) that human valuation may therefore exhibit scientifically at rm o describable scalar characteristics; and (c) that an examination of scalar aspects riginal horit ic f

o of environmental valuation may illuminate the perplexing problems of e h intertemporal evaluation. t he aut t

om Further, these theoretical ideas can be developed into a general approach to r as ing-specif t managing ecological systems as developed in Holling's contribution to this ion ed f volume. Holling argues that, since systems exhibiting these characteristics can peset y function in more than one equilibrium, and since changes in these structural publicat

her t features can occur abruptly, switching systems into alternative equilibria, it will iles creat is h

t be necessary to modify traditional engineering approaches to stability. As a L f

M of

and ot system is controlled (to maximize production of a particular species, for X example) it becomes more brittle, setting it up for pathologies and "flips" into a om yles, r f new steady state. He concludes that in the face of such flips and pathologies, st version near-equilibrium behavior and control (engineering resilience) seems irrelevant print posed

e and the prescriptive goal shifts from questions of maximizing constancy of h heading yield to one of designing interrelations between people and resources that are recom

use t sustainable in the face of surprises and the unexpected. On this view, management attention "shifts to determining the constructive role of instability breaks, ease l been

P in maintaining diversity and persistence and to designs of management that

word

has maintain ecosystem function in the face of unexpected disturbances" (in this ed.

hs, volume, p. 38). This general approach is sometimes referred to as ''adaptive

insert management" (Holling, 1978; Lee, 1993; Walters, 1986). Holling's ideas, and

ally those of others who are exploring similar approaches, may usher in a new era in line lengt thinking about environmental management, an era that is more concerned with original work e h

t processes, functions, and thresholds, and less concerned with system behavior near equilibrium. he original;

ion of And yet (as I think Holling realizes), there is a confounding paradox at the t at o heart of this new and promising approach to management. Where do human ue t r have been accident values and choices fit into this complex system of analysis? Can humans, by y t a managing their own behaviors, shaping them consciously in response to represent m are

l ecological information, "choose" to forbear from certain actions to protect a processes crucial to ecological structure and function. Since most applications errors of hierarchical organizational structures emphasize that control and constraints

age breaks flow down spatiotemporal systems, with the larger and slower-changing P is new digit

h processes constraining the behavior of individuals at lower levels, hierarchical pographic y iles. T t

reasoning is therefore best suited to treat human choices as effects of natural f e ile: ng i f changes. And yet humans are today, without question, important, even t F

D dominant, actors in every "natural" hierarchy. Looked at in this way, it is often P peset and som

is the accumulation of many individual human choices (based in human "values") y h t

that drives changes in ecosystem states. ined, a bout A ret original t

ion. om

r It is possible to characterize this dual nature of human activity—as free ibut f r t cannot choices of individuals on one level and as reaction to constraints imposed from r at not

o the above level—in terms of hierarchical organization (Koestler, 1967; Simon, f 1969).

however, Hierarchy theory embodies two formative assumptions. First, it is version ng,

t perspectival; every measuring or modeling effort takes place from some paper book, at ive specified viewpoint, and a scale must be specified from that viewpoint. Second, at rm o as noted above, hierarchy theory correlates spatial and temporal scale, positing riginal horit ic f

o that smaller subsystems change more rapidly than do the larger systems in e h which they are embedded. Hierarchy in ecology also assumes that the dynamics t he aut t of nature are sufficiently distinct that different levels can be described in om r as ing-specif t relatively discrete terms. Hierarchy theory therefore provides a useful ion ed f formalization of spatiotemporal relationships in complex systems such as peset y natural and managed systems. Humans act freely on the scale of individual publicat

her t choice; and yet these choices are constrained by environmental conditions iles creat is h

t imposed from above. Freedom occurs within constraints imposed by ecological L f

M of

and ot and physical systems that change more slowly. Free action is also, of course, X constrained by political and culturally based rules. om yles, r f What is unusual about my approach is the use of hierarchical thinking to st version inform an explicitly value-laden search for models that will help us to print posed

e understand and manage natural systems to support important social values. This h heading search requires a normative science, and I think conservation biology and recom

use t restoration ecology should be understood within an activist, normative context. The search is for models of natural and physical systems that illuminate the breaks, ease l been

P interactions of human choices and policies with larger features of a landscape.

word

has And, to the extent these models can reflect human values in the structural ed.

hs, hierarchies they posit, they are intended as "prescriptively" adequate as well as

insert descriptive and informational.

ally Taking perspective seriously may require that, from a management line lengt perspective, the hierarchy will be constructed from many local perspectives. original work e h

t Hannon (1994) has therefore proposed that we understand human values as "discounted" across space as well as time; this concept may make it possible to he original;

ion of measure more precisely the relationship of location and intensity of valuation, t at o encouraging a more empirical study of the spatial scale on which social values ue t r have been accident are experienced and articulated. In this context, Hannon's result suggests that y t a environmental values will be highly place-relative and that the perspective and represent m are

l valuations of one community may differ significantly from values as expressed a in another community. errors If Holling and Hannon are correct, humans have evolved special

age breaks sensitivities to patterns perceived in nature. Holling's version sees the P is new digit

h individual, human perspective as organized on three environmental scales. For pographic y iles. T t

f an organism of human size and longevity, the microscale (centimeters to tens of e ile: ng i f meters in space and days to years) is dominated mainly by processes that t F

D determine vegetative structure and by immediate structures (including artificial P peset and som

is ones) that shape individual behavior. At the macroscale (from hundreds to y h t

thousands of kilometers and centuries to millennia), the system is structured by ined,

a slow geomorphological bout A ret original t

ion. om

r processes that define the basic edifice and topographic structure. Processes on ibut f r t cannot this level are normally so slow that they can be considered constants from the r at not

o perspective of human choices. The middle, or mesoscale (tens of meters to f hundreds of kilometers and years to decades), is dominated by natural processes

however, such as outbreaks of fire and plant disease and by human decisions and policies version ng,

t such as grazing and forestry. The mesoscale is therefore of crucial importance paper book, at ive to human habitation; but it is also this scale that exhibits the crucial at rm o discontinuities identified by Holling as changes in ecosystem organization. riginal horit ic f

o Clearly, human choices now shape the environment in countless ways; one e h of the consequences of Holling's argument is that it emphasizes not just the t he aut t

om constraints that work their way down natural hierarchies—the limits on r as ing-specif t searching procedures available to specimens of an animal species of a given ion ed f body size, for example—but also on the impacts that work their way up the peset y hierarchy, such as the cumulative effects of many clear-cuts by many agents on publicat

her t crucial variables such as regional hydrology. Humans, who make conscious iles creat is h

t choices and who are armed with technology and stored fossil energy, can L f

M of

and ot disrupt processes and rapidly introduce discontinuities into the crucial X mesoscale systems. The question is whether human societies will be able to om yles, r f adapt and thrive when the ecological context in which they have evolved st version changes ever more rapidly. Technological optimists accept the disturbance- print posed

e response cycle as inevitable, seeking to ameliorate unexpected negative h heading outcomes of accelerating environmental change through investment. But recom

use t Holling's conclusions seem to imply that ecological systems can be "swamped" by human impacts on productive cycles that will gradually become more brittle breaks, ease l been

P and collapse; his view is therefore more supportive of technological pessimism

word

has than optimism (Holling, 1994). ed.

hs, Be that as it may, the point here is that our perception of scale represents a

insert curious mix of imposed, "objective" structure on the one hand and of "human"

ally construction on the other. Hierarchy theory provides a powerful tool for line lengt characterizing natural systems as architecturally structured, nested dynamics original work e h

t that fall into discrete portions of temporal and spatial possibilities. This aspect provides structure both to physical space as studied by scientists and to space as he original;

ion of it is experienced by conscious human actors. But this "objective" treatment of t at o space and time is only one side of the story. It is also true that humans have, ue t r have been accident within this fixed structure, consciously developed, formulated, and pursued y t a values—embodied in actions and goals—that create a mental or represent m are

l phenomenological representation of physical structures in their experience. I a now turn to a brief discussion of the other side of the story. errors

age breaks

P ARE HUMAN VALUES SCALED? is new digit h pographic y iles. T t

f In this section, I explore the possibility that human values are "scaled" in e ile: ng i f the sense that different human values have distinctive "natural habitats" in t F

D somewhat different contexts and scales. A scalar theory of human valuation has P peset and som is as its goal y h t

ined, a bout A ret original t

ion. om

r the illumination of choices that are made in different time contexts. If we can ibut f r t cannot make sense of shifting temporal contexts in decision making, we may be on the r at not

o way toward a rational means of setting priorities by deciding which human f values are appropriately emphasized in different temporal situations. It will be

however, useful to introduce this idea by contrasting scaled values with the nonscalar version ng,

t values that form the basic building blocks of the value theory of mainstream paper book, at ive economics. There is an interesting sense in which the welfare values of at rm o mainstream economists are nonscalar—all values that will be experienced in the riginal horit ic f

o future are expressed in a present-preference system of value (Norton, 1994). e h The process of discounting costs and benefits across time, in essence, reduces t he aut t all future values to present equivalents. The protection of values that will be om r as ing-specif t experienced in the future is expressed as the willingness of present consumers ion ed f to forgo consumption today to improve the welfare of future generations. The peset y methodological advantages of this reduction are unquestionable—comparing publicat

her t present values is all we can do if we must make a decision in the present. iles creat is h

t Discounting also provides a general explanation of the widespread human L f

M of

and ot behavior of favoring present consumption over future consumption and delay of X unpleasant consequences. om yles, r f But a case can be made that, while values can only affect present decisions st version if they are experienced in the present, some values are experienced print posed

e multigenerationally in the present. These values express themselves in h heading evaluations of characteristics that emerge across multiple generations in a recom

use t culture. Different human values come to the forefront as the context of decision making shifts. Consider, for example, a country that solemnly undertakes a breaks, ease l been

P constitutional convention (Page, 1977; Toman, 1994). In the ideal situation,

word

has delegates to a constitutional convention are able to step outside daily cares of ed.

hs, the present and consider the consequences of various activities and policies on

insert their social and civil life over longer periods of time, over multiple generations.

ally If the constitutional convention is successful, it is because the delegates have line lengt adopted a more timeless perspective. The point of the example is that we do, original work e h

t quite naturally, shift time scales and emphasize shifting motives as we consider different questions in different contexts. Neither the present-value model of the he original;

ion of economist nor the timeless deliberations of constitutional delegates is t at o appropriate in every situation. As our motives shift, we vary the scale of our ue t r have been accident decision making. y t a Thinking about sustainability may be more like thinking about constitutions represent m are

l —multigenerationally—than it is like thinking about immediate consumer a choices in free markets. Preliminary evidence suggests that individuals, in errors considering large-scale decisions affecting the landscape, tend to react as

age breaks "citizens" rather than as "consumers" (Common et al., 1993; Sagoff, 1988). P is new digit

h Varying the temporal scale, or horizon, of a decision shifts the focus of pographic y iles. T t

f discussion, emphasizing some values and focusing on different dynamics; e ile: ng i f different information becomes relevant in this shift. If environmental problems t F

D are problems of scale, it seems reasonable to expect that there is a subtle P peset and som

is interplay between human values and the temporal and spatial horizons we y h t

construct to bound our experienced ined, a bout A ret original t

ion. om

r space. If environmental problems are problems of scale, it makes sense to think ibut f r t cannot explicitly about how we construct mental models of the space in which we r at not

o value nature. f In this spirit, I emphasize the horizon of concern expressed in

however, environmental problems as setting a rough context for understanding and version ng,

t interpreting data in the search for a more harmonious relationship with paper book, at ive ecological and physical systems. Horizons of concern are temporal scaling at rm o devices. Our operating assumption here is that, if Holling is correct, we should riginal horit ic f

o be able to construct an objective model of crucial ecological processes as e h viewed from the perspective of an animal of human lifespan and body size. t he aut t Could we (a) define a set of dynamic, physical models that describe nature from om r as ing-specif t a human perspective and then (b) choose that subset of possible spaces that ion ed f reflect human values. This process of analysis, if successful, might result in an peset y "association" of important social values with particular temporal horizons, and publicat

her t in turn an association of temporal horizons with physical dynamics of a iles creat is h

t particular scale. For example, Norton and Ulanowicz (1992) have shown, using L f

M of

and ot a hierarchical analysis, that the protection of biodiversity is best modeled and X pursued at the landscape ecosystem level. This follows from the temporal om yles, r f horizon of the goal of biodiversity protection—to protect biological resources st version for many human generations into the future. print posed

e But we have now deserted traditional "pure" and "value-free" science; we h heading have recognized that the choice of boundaries for our physical models can recom

use t express values and concerns that are shaped by our value-laden experience of space. The goal of this examination is to think more explicitly about this breaks, ease l been

P interaction between values and modeling and the ways in which our

word

has representations of natural processes and environmental problems embody ed.

hs, spatial aspects of an action-oriented model for articulating environmental policy

insert problems (a process that is represented abstractly in Figure 1).

ally Since it is a goal of model building in environmental management that the line lengt models inform environmental decision making to improve communication original work e h

t between scientists and the public, we conclude that any model for this purpose must be fairly simple in structure. It must, that is, be a simple enough he original;

ion of representation of multiscaled natural processes to serve as an aid in public t at o discussion of the goals of a forest management plan or a plan for ecological ue t r have been accident restoration of a river system. Our prescriptive, multiscalar models must provide y t a a publicly useful vocabulary for discussing environmental goals. We can in this represent m are

l way shape our models of management by associating them with the temporal a and spatial scales of the natural dynamics that generate the values guiding our errors choice of goals. In this sense we are searching for a spatiotemporally organized,

age breaks and ecologically informed, phenomenology of the space in which individuals P is new digit

h formulate and pursue personal and environmental values. pographic y iles. T t

f To initiate discussion, I suggest three basic scales, each of which e ile: ng i f corresponds to a temporally distinct policy horizon: (1) locally developed t F

D values that express the preferences of individuals, given the established limits P peset and som is and rules— y h t

ined, a bout A ret original t

ion. om

r physical laws, governmental laws, and market conditions, for example—within ibut f r t cannot which individual transactions take place; (2) a longer and larger community- r at not

o oriented scale on which we hope to protect and contribute to our community, f which might be taken to include the entire ecological community; and (3) a

however, global scale with essentially indefinite time scales on which humans express a version ng,

t hope that their own species, even beyond current cultures, will survive and paper book, at ive thrive. Table 1 exhibits these scales and shows how they correlate with different at rm o dynamics in the social and physical world. riginal horit ic f

o On the first scale, which unfolds in the relatively short and local space in e h which individuals make economic choices, the economics of costs and benefits, t he aut t

om if supplemented with a sense of individual justice and equity, can provide a r as ing-specif t useful model. The middle scale, in which we feel concern for our cultural ion ed f connection to the past and the future, is especially important for two reasons. peset y Viewed socially, this mesoscale, multigenerational level is the one on which we

publicat 2

her t protect, develop, and nurture our sense of who we are as a culture. It is on this iles creat is h

t level that a society decides what kind of a society it will be. These decisions are L f

M of

and ot expressed in art, in religion and spirituality, and in governing political X institutions such as a constitution. It is on this scale that concern emerges om yles, r f regarding a culture's interaction with the ecological communities that form its st version context. The second scale is doubly important because it corresponds roughly to print posed

e the ecological time scale on which multiple generations of human individuals, h heading organized into communities, must relate to populations of other species that recom

use t share our habitat. It also corresponds to the mesoscale of ecological organization emphasized by Holling. It is this scale that is crucial in breaks, ease l been

P understanding interactions between humans and nature on landscape scales.

word

has The point of this paper has been to suggest that, in addition to single-scale ed.

hs, valuation systems such as the one offered by economists, there exists an

insert alternative, scale-sensitive framework in which to evaluate human actions that

ally reshape the landscape. That approach attempts to associate a triscalar line lengt conception of human valuation with Holling's triscalar landscape, suggesting original work e h

t that we can sort

TABLE 1 Correlation of Human Concerns and Natural System Dynamics at he original; ion of

t Different Temporal Scales at o Temporal Horizon of Human Time Scales Temporal Dynamics in ue t r have been accident Concern Nature y t a Individual and economic 0-5 years Human economies represent m are

l concerns a Community, intergenerational Up to 200 years Ecological dynamics; errors bequests interaction of species in communities

age breaks Species survival and our genetic Indefinite time Global physical systems P is new digit

h successors pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r environmental problems and decisions according to the temporal and spatial ibut f r t cannot scale of the impacts of those decisions. Since the system is pluralistic and the r at not

o spatial levels are governed by relatively discrete dynamics, the features of the f mesoscale landscape that are important to humans on intergenerational scales

however, may depend on protecting processes at different scales. The injunction not to version ng,

t change natural processes irreversibly into new equilibria that are unproductive, paper book, at ive or otherwise undesirable from a human perspective, represents a commitment to at rm o conceive management ecologically. riginal horit ic f

o Modern ecological knowledge forces us to conclude that we must act as e h members of natural communities as well as the human social community; it t he aut t

om follows also that we must pay attention to the context in which our values are r as ing-specif t formulated and acted on. That context is best understood as the interaction ion ed f between a culture and its habitat that is described in the natural history of a peset y place. That natural history must reach back into time and project itself publicat

her t creatively into the future. Good management requires, in the immortal words of iles creat is h

t Leopold, learning to "think like a mountain," on the scale of time, that is, in L f

M of

and ot which wolves, deer, and hunters interact as populations on a mountainside X (Leopold, 1949; Norton, 1991). Thinking intergenerationally apparently om yles, r f requires that we pay special attention to the mesoscale of the landscape, the st version scale at which human populations interact as parts of ecological communities. print posed e h heading A METAMODEL FOR DECISION MAKING IN A recom use t DISCONTINUOUS AND UNCERTAIN WORLD breaks, ease l been

P In this paper more questions have been raised than answered. I hope only

word

has that they are fruitful questions and that answers may begin to point toward a ed.

hs, more systematic, scientific, and value-sensitive approach to the difficult

insert problems of scale and human valuation. This last section offers a practical

ally proposal in the form of a series of devices—I call them risk decision squares— line lengt which purport to represent in a general and abstract way the decision space original work e h

t encountered by decision makers in the uncertain and discontinuously changing physical space that humans necessarily encounter when they contemplate, and he original;

ion of alter, their multiscalar environment. t at o If I cut one tree and plant another in its place, have I changed the natural ue t r have been accident world in a way that might be held blameworthy by some member of a future y t a generation? In most cases of cutting and replacing one tree, I think I have not represent m are

l harmed the future—at least not in any morally significant way. At least two a features of this simple scenario suggest the cutting of the tree is an errors intertemporally blameless act. First, I have taken immediate steps to replace the

age breaks tree, thereby initiating restoration and ensuring, insofar as I could, that my P is new digit

h damage would be reversed in the course of nature's time. Second, the pographic y iles. T t

f description of my act was to cut a single tree, which apparently limits the scale e ile: ng i f of my destruction to a single, specifiable locale. t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading FIGURE 2 Risk decision square: neutral version. Source: Norton (1995a). recom use t breaks,

ease Let us build on these two ideas that the moral gravity of an action affecting l been P the environment is determined by the irreversibility of its effects and by the word has ed. spatial scale of those effects. We can do so by introducing a decision space hs, defined by two continua, each of which ranks possible outcomes of a policy or insert action—one ranks the impacts according to how long natural processes will ally

line lengt require to "heal" negative alterations to the environment, and the other ranks the original work

e spatial scale of the impact. These two scales are combined in Figure 2. h t

Decisions with quickly reversible impacts and decisions affecting small scales probably do not raise questions of intergenerational moral importance. They fall he original; ion of t

at in the northeast, the southeast, or the southwest quadrants of our decision space; o they can be decided on normal, individualistic criteria of economic efficiency, ue t r have been accident y t balanced, we hope, by considerations of interpersonal equity. Ecological a represent m

are economists and environmental managers should, according to this analysis,

l a categorize environmental problems according to the irreversibility and scale of errors the risks involved as a first step in any problem analysis, because this categorization determines the horizon of concern involved in the decision. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Note that the first continuum calibrates the temporal scale of our actions— ibut f r t cannot the temporal horizon of possible impacts of an action helps us to define the r at not

o outer limits of our responsibility. The second continuum locates decisions f according to the potential spatial scope of their effects. This ensures that we

however, distinguish between the act of cutting down and replacing one tree and a case in version ng,

t which cutting and replanting that tree is one incident in an ongoing process that paper book, at ive will result in the clear-cutting of a whole watershed. In this latter case, we must at rm o consider the scale of the act not as that of cutting a single tree, but as part of a riginal horit ic f

o larger-scaled action—clear-cutting a whole watershed—which is sure to affect e h an entire ecosystem. t he aut t

om We can dramatize the difference between the decision model of r as ing-specif t economists and that of Holling and the ecologists by comparing Figures 3 and ion ed f 4. Because they measure all values as present values, economists treat every peset y possible loss as potentially compensable, which is justified if every resource has

publicat 3

her t a suitable substitute. The decision space of economists is therefore confined to iles creat is h

t the dimension-less present, resulting in an economists' version of the decision L f

M of

and ot space. Exploiting hierarchy theory's organizing assumption—that large spatial X scale of a system is om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks FIGURE 3 Risk decision square: economists' version. Source: Norton (1995a). P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading

recom FIGURE 4 Risk decision square: ecologists' version. Source: Norton (1995a). use t breaks, ease l been correlated with relatively slower rates of change—we can superimpose a P hierarchical model on the decision space landscape, allowing us to locate risks word has ed.

hs, on an ecologically defined decision space. One way to take scale seriously in environmental problems is to employ models such as this to identify risk insert decisions according to their ecological and social significance. These are both ally

line lengt most difficult tasks. original work

e I believe Holling's models take us a long way toward identifying h t ecologically significant processes to monitor and protect when he introduces the idea of ''keystone processes," which he defines as processes that structure the he original; ion of t at o landscape at different scales (Holling, 1992, p. 478; also see Harwell et al., 1994). And he describes the crucial variables in the decision of what to protect, ue t r have been accident y t

a and how: "The question for issues of human transformation from the scale of represent m are

fields to the planet, therefore, is how much change does it take to release l a disturbances whose intensity and extent are so great that the renewal capital is errors destroyed or regeneration of the existing plant species is prevented" (Holling, 1992, p. 482). This poses the question of ecological significance in a way that age breaks P

is new digit allows us to specify in general h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r terms what we mean by ''ecologically sustainable activities." The difficult ibut f r t cannot questions remaining on the ecological side are therefore to verify and refine r at not

o Holling's results and to begin to specify the limits of risk to ecological f communities consistent with a sustainable use of ecological resources for

however, specific systems, because Holling's result implies that limits will be different in version ng,

t every locale. paper book, at ive But despite offering progress in defining ecologically significant change, at rm o Holling's model is not designed to address the other crucial variable in decisions riginal horit ic f

o regarding what natural processes to protect—the role of human values in the e h transformation of evolving landscapes. Besides determining whether an action t he aut t

om is "ecologically significant" in Holling's sense, we must also make judgments r as ing-specif t regarding which near-equilibrium states are desirable, which may require ion ed f balancing advantages and disadvantages of various policy proposals across peset y multiple scales. I have suggested that humans may experience their world on publicat

her t roughly three scales: the individual, short-term scale; the intergenerational, iles creat is h

t community scale; and a global scale. It is useful to understand environmental L f

M of

and ot management as occurring within such a three-tiered phenomenological space. I X have also suggested that distinct and irreducible human values are supported on om yles, r f different levels of the hierarchical system. It may be possible to conceptualize st version environmental decision making within such a phenomenological space and also print posed

e to improve on our mental representations—make them more sound, ecologically h heading —by superimposing Holling's "natural" hierarchy on the hierarchy of human recom

use t values. This description of the new focus of ecologically informed management points toward a new research program—determining which social values are breaks, ease l been associated with particular ecological dynamics. The triscalar system of human P

word

has value may prove useful in organizing this research program. ed.

hs, This pluralistic value analysis of course implies that there will sometimes

insert be conflicts among values that are experienced on different levels (as well as

ally conflicts, such as value conflicts among human individuals, which take place on line lengt one level); for example, our first choice as an economic policy, as measured by original work e h

t its expected impact on social welfare in the short-term, may cause rapid alteration of a key ecosystem process, threatening longer-term well-being on a he original;

ion of larger and longer scale. The proposed policy has negative impacts on ecological t at o structure, posing an apparent conflict. But the scalar analysis, while it cannot ue t r have been accident resolve all these conflicts, does offer a constructive means to address them. y t a There will be a class of policies that will improve individual welfare by represent m are

l improving economic efficiency, another class of policies that will improve the a functioning of ecological communities, and another that will have no impact on errors the stable, geomorphological features of the landscape that, in normal times,

age breaks provide the stable background for economic, cultural, and genetic evolution and P is new digit

h adaptation. pographic y iles. T t

f A wise policy can be described as one that has positive impacts on some e ile: ng i f levels and negative impacts on none of the levels, a criterion I call the Scalar t F

D Pareto Optimality criterion (Norton, 1995b). The Pareto Optimality criterion, P peset and som is when applied by economists to individual participants in an economic choice, y h t

ined, a bout A ret original t

ion. om

r insists that an action is good if it helps some individuals and harms nobody. But ibut f r t cannot applying this policy criterion results in no action if any individual is harmed by r at not

o a proposed policy. Because there are in fact few, if any, policies that harm f nobody, the Pareto Optimality criterion, applied at the individual level, has

however, therefore been honored not in practice but only in principle, because it would version ng,

t result in policy gridlock. By abstracting from individuals—treating the paper book, at ive individuals on level one as "representative" individuals and resolving their at rm o disagreements according to traditional ethical concepts—and by applying the riginal horit ic f

o Pareto Optimality criterion in a scalar fashion, it is possible to define a good e h environmental policy as one that has a positive impact on socially desired t he aut t variables at some levels of the spatiotemporal hierarchy, and negative impacts om r as ing-specif t on none of those socially desirable variables. This formulation of the decision ion ed f criterion is equivalent, I believe, to the outcome that would occur if peset y "representative" individuals of each community applied, from their own local publicat

her t perspective, the three-tiered decision space outlined in the ecologists' version of iles creat is h

t the risk decision space. Risk decision squares therefore provide a methodology L f

M of

and ot for relating impacts of human choices on the landscape to dynamics that are X associated with important social values. om yles, r f st version NOTES print posed e h heading 1. See Karr (in this volume) and Costanza et al. (1992) for further discussion of these concepts. recom

use t 2. John Rawls (1971) and others (Norton, 1989, 1991; Page, 1977) have explored the idea that

breaks, this intergenerational aspect of decision making can be simulated by imagining rational ease l been

P individuals who design fair rules to govern resource depletion from behind a "veil of ignorance"

word regarding which generations they will inhabit. has ed.

hs, 3. See Norton and Toman (1995) for a discussion of the importance of views on substitutability of resources in determining policy concerns. insert ally line lengt

original work REFERENCES e h t

Allen, T. F. H., and T. W. Hoekstra. 1992. Toward a Unified Ecology. New York: Columbia University Press.

he original; Allen, T. F. H., and T. B. Starr. 1982. Hierarchy: Perspectives for Ecological Complexity. Chicago, ion of t at o Ill.: University of Chicago Press. Common, M. S., R. K. Blarney, and B. G. Norton. 1993. Sustainability and environmental ue t r have been accident valuation. Environmental Values 2:299-334. y t a Costanza, R., B. Norton, and B. Haskell, eds. 1992. Ecosystem Health: New Goals for represent m are

Environmental Management. Washington, D.C.: Island Press. l

a Hannon, B. 1994. Sense of place: Geographic discounting by people, animals and plants. Ecological

errors Economics 10:157-174. Hardin, G. 1968. The tragedy of the commons. Science 162(December 13):1243-1248. Hatwell, M., J. Gentile, B. Norton, and W. Cooper. 1994. Ecological Significance. EPA/630/R-94/ age breaks 009. Issue paper prepared for the Risk Assessment Forum, U.S. Environmental Protection P is new digit

h Agency, Washington, D.C. pographic y iles. T t

Holling, C. S., ed. 1978. Adaptive Environmental Assessment and Management. London: John f e

ile: Wiley. ng i f t

F Holling, C. S. 1992. Cross-scale morphology, geometry, and dynamics of ecosystems. Ecological

D Monographs 62(4):447-502. P peset and som is y h t

ined, a bout A ret original t

ion.

om Holling, C.S. 1994. An ecologist's view of the Malthusian conflict. In K. Lindahl-Kiessling and H. r ibut f r Landberg, eds. Population, Economic Development, and the Environment. New York: t cannot Oxford University Press. r at not

o Horton, T. 1987. Bay County. Baltimore, Md.: Johns Hopkins University Press. f Koestler, A. 1967. The Ghost in the Machine. New York: Macmillan. Kuhn, T. 1962. The Structure of Scientific Revolutions. Chicago, Ill.: University of Chicago Press. however, Lee, K.N. 1993. Compass and Gyroscope: Integrating Science and Politics for the Environment. version ng,

t Covelo, Calif.: Island Press. paper book, at ive Leopold, A. 1949. A Sand County Almanac and Sketches Here and There. London: Oxford at rm University Press. o

riginal Levin, S.A. 1992. The problem of pattern and scale in ecology. Ecology 73(6):1943-1967. horit ic f

o Nelson, J. L. 1995. Health and disease as "thick" concepts in ecosystemic contexts. Environmental e

h Values: t he aut t

Norton, B.G. 1989. Intergenerational equity and environmental decisions: A model using Rawls' om r

as veil of ignorance. Ecological Economics 1(2): 137-159. ing-specif t Norton, B. G 1991. Toward Unity Among Environmentalists. New York: Oxford University Press. ion ed f Norton, B.O. 1994. Economists' preferences and the preferences of economists. Environmental peset

y Values 3:311-322. Norton, B.G. 1995a. Evaluating ecosystem states: Two competing paradigms. Ecological publicat

her t Economics 14:113-117. iles creat is

h Norton, B.G. 1995b. Reduction or integration: Two approaches to environmental values. In t L f Environmental Pragmatism, A. Light and E. Katz, eds. London: Routledge & Kegan Paul. M of

and ot

X Norton, B. G., and M. A. Toman. 1995. Sustainability: Ecological and Economic Perspectives. Background paper for Colloquium on Sustainability, organized by Environmental Law om yles, r f Institute, Washington, D.C., January 10, 1995. st version Norton, B., and R. E. Ulanowicz. 1992. Scale and biodiversity policy: A hierarchical approach. Ambio 21(3)(June):244-249. print posed

e O'Neill, R. V, D. L. DeAngelis, LB. Waide, and T. F. H. Allen. 1986. A Hierarchical Concept of h

heading Ecosystems. Princeton, N.J.: Princeton University Press.

recom Page, T. 1977. Conservation and Economic Efficiency. Baltimore, Md.: Johns Hopkins University

use t for Resources for the Future.

breaks, Prigogene, I., and I. Stengers. 1984. Order Out of Chaos: Man's New Dialogue with Nature. ease l been Toronto, Ontario: Bantam Books. P Quine, W.V.O. 1960. Word and Object. Cambridge, Mass.: MIT University Press. word has ed. Rawls, J. 1971. A Theory of Justice. Cambridge, Mass.: Harvard University Press. hs, Sagoff, M. 1988. The Economy of the Earth: Philosophy, Law and the Environment. Cambridge,

insert England: Cambridge University Press. Seamon, D., and R. Mugerauer. 1989. Dwelling, Place, & Environment: Towards a Phenomenology ally of Person & World. New York: Columbia University Press. line lengt

original work Simon, H. A. 1969. The Sciences of the Artificial. Cambridge, Mass.: The MIT Press. e

h Toman, M.A. 1994. Economics and 'Sustainability': Balancing Tradeoffs and Imperatives. Land t Economics 70(4) (November):399-413. Tuan, Y.F. 1971. Man and Nature. Commission on College Geography, Association of American he original;

ion of Geographers. t at o Tuan, Y.F. 1977. Space and Place: The Perspective of Experience. Minneapolis, Minn.: University of Minnesota Press. ue t r have been accident y

t U.S. Environmental Protection Agency. 1983. Chesapeake Bay: A Profile of Environmental a Change. Washington, D.C.: U.S. Environmental Protection Agency. represent m are

l Walters, C. 1986. Adaptive Management of Renewable Resources. New York: Macmillan. a Williams, B. 1985. Ethics and the Limits of Philosophy. Cambridge, Mass.: Harvard University errors

Press. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html A PERSPECTIVE ON THE RELATIONSHIP BETWEEN ENGINEERING AND ECOLOGY 65 e h t be

ion. om r ibut f r t cannot r at not A Perspective on the Relationship Between o f Engineering and Ecology however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Robert Herman t he aut t

om r as ing-specif t NEW AWARENESS ion ed f peset

y As the twenty-first century approaches, humanity finds itself at the dawn

publicat of new awareness. Throughout recent human history technological development her t iles creat is

h has largely focused on solutions to specific problems with important outcomes t L f

M of affecting human existence, such as the freedom to live, develop ideas, and move

and ot X about freely in relative comfort, provided that, in principle, others are not om yles, r

f injured. It is mainly from the perspective of the individual that the world has st version almost reached the twenty-first century. This point of view is no longer thought

print to be valid by many people, and environmental justice now appears to require posed e h

heading the consideration of collective effects—that is, the concept of the "commons."

recom Unfortunately, this concept is mainly human centered and often does not take use t into account the well-being of other living creatures. breaks, ease l been It is generally recognized that the quality of the environment must be P maintained so that living creatures can survive, that is, extract oxygen and water word has ed.

hs, and give off waste products. Our living conditions are intended to give us warmth, comfort, and safety and serve as a place for physical and spiritual insert nourishment, while at the same time their creation influences the collective ally

line lengt environment, causing such problems as air pollution, solid-waste accumulation, original work

e and the greenhouse effect. The subtle and insidious nature of the impacts h t resulting from greenhouse gas buildup makes a truly equitable societal response very difficult. This is especially so when we recall that the contribution of he original; ion of t at o human effluents in many instances is a small part of the natural balance.

ue t Unfortunately, however, we humans are not yet in a position to understand all r have been accident y t

a the intricacies of the biogeochemical balances that exist within the world's represent m are

ecosystems and the influence l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r that small perturbations may have, such as an annual El Niño whose effects ibut f r t cannot persist for 10 years. r at not o f PRINCIPLES FOR ENGINEERING WITHIN ECOLOGICAL however,

version CONSTRAINTS ng,

i t paper book, at ive New applications of technology and engineering must come to terms with at rm o the social and ethical values of the society in which they are to be made. riginal horit ic f

o Engineering must be applied in such a way that innovations make proper e h contributions to the greater community at large. The development of sound t he aut t

om engineering practices can help conserve and restore the environment through a r as ing-specif t proper balance between engineering principles and environmental ion ed f considerations. Principal among these considerations must be a strengthening of peset y engineering accounting to include properly the value and costs to the affected publicat

her t ecosystems. Over and above that, societies must avoid becoming iles creat is h

t technologically overcommitted. It is preferable if engineering know-how is L f

M of

and ot applied sparingly, with the goal of simplifying tasks and enhancing the quality X of life. Engineers should not be encouraged to pursue the application of om yles, r f complicated and ingenious devices for unimportant functions. The appropriate st version criterion for the ethical application of engineering within ecological constraints print posed

e is conservatism, while operating within the natural system rather than infringing h heading on it or overcoming it, having a sense of the whole of the environment, and recom

use t abstracting no more than a particular function warrants. Systems should be developed to be as flexible and forgiving as possible to avoid drastic and breaks, ease l been

P irreversible consequences when something goes wrong. This is counter to the

word

has traditional Baconian view, often held even now in some segments of our ed.

hs, society, that nature should be conquered.

insert An ecological approach to engineering must take into account that nature

ally responds systematically, continuously, and cumulatively. In support of these line lengt concepts, ecologists should make available to the engineering community as original work e h

t much knowledge as possible on the ecosystems that could be affected, their vulnerabilities, and the specific technical reasons for caution. Perhaps the he original;

ion of ecological community should develop a new applied subject area in which t at o consideration is given to engineering applications of a specific type and the ue t r have been accident resultant stresses, costs, and effects on related ecosystems are evaluated, using y t a various generic cases. It is beyond the capability or intent of the average represent m are

l engineer to become both a creative technologist and an ecologist. a As alluded to earlier, when engineering applications are planned, care errors should be taken to consider the social and ecological costs. Today much

age breaks depreciation of environmental capital is going unrecorded. For example, P is new digit

h Passent (1994) states that between 1970 and 1989 Costa Rica's forest, soils, and pographic y iles. T t

f fisheries depreciated by more than U.S. $4 billion. He goes on to say many e ile: ng i f authors believe that resource depletion would be obvious if ecological t F

D accounting were included within the national income accounting framework. P peset and som is Such depreciation takes an y h t

ined, a bout A ret original t

ion. om

r enormous toll on a country's capacity to generate future income. In fact, in a ibut f r t cannot developing country a lower per capita income involving sound, ecologically r at not

o focused business may actually produce a higher standard of living for its f people. The United Nations Development Program has devised the Human

however, Development Index, which ranks countries on the basis of a combination of version ng,

t adjusted per capita gross national product, longevity, and educational paper book, at ive attainment. From this is derived an average deprivation index. It is interesting at rm o that according to this index the United States ranks sixth worldwide, after riginal horit ic f

o Japan: Canada, Norway, Switzerland, and Sweden. With regard to the e h depreciation of environmental capital, engineers must also be aware of any t he aut t remote effects of their works. om r as ing-specif t In the development of complex systems, careful consideration should be ion ed f given to what should be automated and what should not. Many times in an peset y automated system (e.g., telephone marketing) the function is performed badly publicat

her t and conceals the essence of the situation. Automation commonly treats iles creat is h t

L f everything in an inanimate way. Incommensurable factors, individual

M of

and ot differences, local context, and the weighting of evidence are often overlooked X though embedded in these factors may be the essence of what is important. om yles, r f With automation the process may be subtly transformed; the process may run st version smoothly, it may be productive, but it may also be out of line with the nature of print posed

e things and the essential problems. Such a situation can lead to artificial or h heading unnatural boundary conditions with regard to interactions with other systems. recom

use t On the other hand it is ethically proper that engineering be applied in a timely manner to ensure survival by diminishing human disease, drudgery, and breaks, ease l been

P the threat of starvation; but in so doing the application of engineering concepts

word

has takes on an ethical component as well, to ensure that new approaches improve ed.

hs, the quality of human life. In the developing world, technological applications

insert should seek to employ native labor and local resources as much as possible,

ally should serve to maintain the natural environment as well as traditional customs, line lengt and should focus on teachable know-how. This may not be an easy assignment original work e h

t and will require an application of social knowledge beyond what is commonly taught or expected of the engineer today. Perhaps a new discipline of social he original;

ion of engineering should be considered in which the mix of the two topics would take t at o on a more integrated structure. ue t r have been accident These considerations suggest some key research goals and policy objectives. y t a • The "built environment" should have long-term integrity that can enhance represent m are

a the quality of life while taking into account the interactions among the errors

various elements, namely, energy, transportation, communication (or information), public health and safety (e.g., water and waste), industry,

age breaks construction, the environment, and others. The idealist's future goals for P is new digit h

pographic infrastructure development must consider such features as quality, y iles. T t

e flexibility, adaptability, reliability, cost-effectiveness, and, perhaps most ile: ng i f t important, crisis management, especially for the complex city. F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r • We need to develop and understand "industrial metabolism" to make ibut f r t cannot industrial processes more efficient through the proper use of by-products r at not

o and wastes generated during technological processes. In this context we f need to aim to lessen environmental impacts through flexible management

however, practices that involve innovative reuse, remanufacturing, and recycling of version ng,

t "wastes" (Ayres, 1989; Frosch, 1993). paper book, at ive • Future engineering policy should focus on environmentally friendly design. at rm o It is at the design stage that strategies can be developed to address riginal horit ic f

o environmental issues, since it is during design that consideration can be e h given to the types of resources and manufacturing processes to be t he aut t

om employed, which in the final analysis determine the detailed character of r as ing-specif t the by-products and the waste stream. Such considerations may often lead ion ed f to the added benefits of improved efficiency and quality, reduced costs, and peset y increased industrial competitiveness (U.S. Congress, Office of Technology publicat

her t Assessment, 1992). Proper cost accounting of industrial processes and their iles creat is h

t ecological impacts will assist industry to justify environmentally sound L f

M of

and ot business practices. X • There should be an aggressive public education effort to explain the om yles, r f scientific basis for concerns regarding air pollution, stratospheric ozone st version depletion, global warming, and pollution of the oceans, land, and print posed

e groundwater, especially as these matters relate to choices in human behavior. h heading • We need better understanding of the effects of government regulations and recom

use t public relations on the interaction of engineering with ecology, and better understanding of the impact of the media in generating and influencing the breaks, ease l been

P public mind-set, which is a significant determinant of public policy. A

word

has realistic approach must take into account the politicization of technical and ed.

hs, scientific problems as well as the reality that in our highly litigious culture,

insert constraints are considered to be anathema.

ally • Administrative structures should allow for processes to readjust de- line lengt centrally with a minimum of central intervention or control, except, of original work e h

t course, for cases of catastrophic breakdown. • Land planners need a clearinghouse of information on the ecology of an he original;

ion of area, continually updated. The same information should be available to the t at o public and should precede any environmental impact studies once land use ue t r have been accident decisions have been made. y t a • Detailed environmental hazard contingency plans should also be drawn up represent m are

l and made available to governmental authorities for all scales of impacts, a local, county, state, regional, and beyond. This would help to ward off errors improper responses to emergencies. It would also be especially important

age breaks as it relates to jurisdictional responsibilities in times of emergency, both P is new digit

h domestic and foreign. pographic y iles. T t

f e ile: ng i f t

F AN EXAMPLE: TRANSPORTATION SYSTEMS D P peset and som is The many-faceted nature of these various considerations may be y h t

demonstrated by considering a particular engineering-based aspect of modern ined,

a society, bout A ret original t

ion. om

r transportation systems. One of the principal greenhouse gases, carbon dioxide, ibut f r t cannot is released whenever fossil fuel is burned. In addition, gasoline internal r at not

o combustion engines release nitrous oxides, carbon monoxide, and volatile f organic compounds. These gases, in turn, lead to the production of smog and

however, tropospheric ozone, the latter also being an important greenhouse gas. Some version ng,

t vehicles also emit chlorofluorocarbons, which both act as a greenhouse gas and paper book, at ive catalyze the destruction of stratospheric ozone. Chlorofluorocarbons serve as at rm o the thermodynamic working fluid in all but the most modern vehicle air riginal horit ic f

o conditioners and are constituents of the foam cushioning used in car seats. They e h are also important as degreasing agents and fire extinguishing agents. While t he aut t these effluents can have an impact on human health and comfort, their effects om r as ing-specif t are not immediate nor are they restricted exclusively to the user. It is in the ion ed f context of their spatial effects as well as the long duration of their effects on the peset y commons that the release of chlorofluorocarbons to the atmosphere takes on publicat

her t great significance for the biosphere. iles creat is h t

L f As more and more people migrate to cities and life is developed in an

M of

and ot increasingly global economy, the design of transportation and communication X systems provides us with the greatest flexibility for the mitigation of global om yles, r f climate change. It is particularly important that these considerations be taken st version into account as the developing world begins to expand its use of fossil fuel and print posed

e advanced transportation systems. The future climate of the globe may be h heading strongly dependent on these technological decisions. It is with these ideas in recom

use t mind that a number of critical areas require intensive study and that various critical questions can be raised: breaks, ease l been P

• Should travel and transportation be priced to cover the costs of impacts on word has

ed. the environment? Should work trips be excluded? Should communication hs, that reduces travel be subsidized? insert • Should there be an excise tax on raw materials transported great distances,

ally since energy is required to transport them and ecological risks may be line lengt

original work enhanced during their transport? Should there also be a special e h t

environmental impact tax on items transported great distances when they could be produced closer to their destination? he original; ion of

t • Should the cost of a new car reflect the value of the useful materials at o abandoned in the old car that is being replaced? ue t r have been accident

y • Should individual and business taxes reflect the impact of transportation t a emissions on the global commons? represent m are

a • Should much greater effort be made to explore and exploit the possible errors

benefits of telecommunication? Since vehicular transportation requires massive investment in

age breaks infrastructure as well as provision for frequent refueling, there are other P is new digit h

pographic fundamental and ethical questions to be considered. y iles. T t

e • What means of transportation is fair and equitable in the context of the ile: ng i f t commons? F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r • What land development and transportation principles should be practiced to ibut f r t cannot ensure the most efficient infrastructure and to maintain the environmental r at not

o commons? f • What complementary role should communication play?

however, All of these types of questions must be considered in spite of our version ng,

i t

paper book, inadequate knowledge of the detailed character of urban traffic. In this context at ive at

rm there is a strong interaction possible between communication and transportation o

riginal —"telecommunication" as it is now called. Communication can sometimes horit ic f o

e replace travel, and communication may make travel more efficient and safe, for h t

he aut example, through the control of traffic in systems such as ITS (Intelligent t

r Transportation Systems, formerly IVHS, Intelligent Vehicle Highway Systems) as ing-specif t (Catling, 1993; ITS America, 1995; IVHS America, 1992; Whelan, 1995). On ion ed f

peset the other hand, it should be kept in mind that communication can also raise y travel demand with a resultant offsetting effect. publicat her t

iles creat We focus on transportation in an attempt to illuminate some of the general is h t L f points made earlier. In practice, all components of the civic infrastructure M of

and ot should be examined as a single system to understand the interactions between X

om the various elements of the system. The infrastructure is a reflection of our yles, r f st version human characteristics and, therefore, we need to understand the dynamic evolution of cities to move forward in an effective social and technological print posed e manner, one that is compatible with our human character. h heading recom use t COMPLEXITY breaks, ease l been P

The human enterprise is critically dependent on our understanding of, and word has

ed. ability to address and solve, highly complex problems. These are problems hs, whose description must be specified in terms of an intermediate number of insert variables, not just two or three variables which would generally be tractable, nor

ally an extremely large number such as can be handled by the methods of statistical line lengt

original work physics. Systems with an intermediate number of variables are least well e h t

understood. There is an urgency to learn how to handle such problems, since the future development of human society will be progressively more dependent on he original; ion of

t their solution. Perhaps with skill and application it will be possible to discover at o simplifications that result from collective effects, so that the number of ue t r have been accident

y pertinent independent variables can be reduced. t a One of the first systems with an intermediate number of variables to enjoy represent m are

a substantial progress is vehicular traffic (Herman, 1992; see also Johnson, 1993, errors

and Zuckermann, 1991). Even though traffic systems are complex, with individual actors independently operating independent machines, 75 percent of

age breaks the variance in the fuel consumed per unit distance for an automobile with a P is new digit h

pographic gasoline combustion engine in an urban street network can be explained by a y iles. T t

e single variable, average speed. In addition, it is also possible to describe the ile: ng i f t overall F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r traffic in an urban street network through a two-fluid model with only two ibut f r t cannot parameters. The main assumption in the model is simply that the average speed r at not

o of the moving traffic is proportional to the average fraction of the vehicles that f are moving (Herman, 1992; Herman and Prigogine, 1979). These are but two

however, examples of the great simplicity resulting in some cases where many variables version ng,

t in a complex problem are nonlinearly intertwined. In spite of the large number paper book, at ive of variables and effects, including stochastic effects and fluctuations, the net at rm o results can be formulated in an extremely simple, compact manner. On the other riginal horit ic f

o hand, there are situations in which a result is dependent on a large number of e h interacting variables, each of which is responsible for only a small percentage t he aut t of the total effect. Such is the case for the decline of the salmon population in om r as ing-specif t North America, for which fixing one of a relatively large number of pertinent ion ed f factors not only may not do any good but may actually cause harm, since one peset y does not fully understand the interrelationship among the variables (see Karr, in publicat

her t this volume). iles creat is h t

L f It is apparent that when we deal with such complex problems we do not

M of

and ot understand in advance all the consequences of our decisions. In this context we X refer to Edward Tenner, who recently wrote a very interesting article that om yles, r f addresses some of the above-mentioned difficulties when dealing with complex st version problems (Tenner, 1991). The article is entitled ''Revenge Theory or why new print posed

e highways develop gridlock, labor saving appliances create more housework, h heading simplified tax regulations are harder to follow, paperback books cost what recom

use t clothbound books used to, and why Murphy was an optimist." While it is not easy to classify all the types of outcomes that cause us difficulty, Tenner breaks, ease l been

P suggests the following set: repeating, recomplicating, recongesting,

word

has regenerating, and rearranging. We might suggest reconstituting as well. ed.

hs, With regard to repeating, we are all familiar with the fact that having a

insert time-saving device often induces us to use it more frequently and thus use more

ally time. Recomplicating is exemplified by a new device such as the push-button line lengt telephone, which makes some operations easier and is then overpowered by original work e h

t elaborate systems developed to take advantage of it. In recongesting, technological change opens new possibilities but concomitantly encourages new he original;

ion of demand that soon clogs the system again, as in the case of the automobile. t at o Regenerating appears after a problem seems to have been solved. This is ue t r have been accident apparent in connection with pest control, which may work for a while and then y t a revert to the original situation because the pesticide also kills the pest's natural represent m are

l predator or selects for pesticide-resistant pests. Tenner finally discusses a rearranging, which is the revenge effect that shifts a problem in space or time. errors Thus, air-conditioned subway cars may provide a cooler ride, but the stations

age breaks and tunnels become considerably warmer, which in turn can cause the air- P is new digit

h conditioning units in the train to break down. pographic y iles. T t

f With respect to reconstituting, we note that when a significant new element e ile: ng i f is introduced into a system, it can generate total change. If you add or subtract t F

D something, the overall system may be altered. Examples are the removal of some P peset and som is y h t

ined, a bout A ret original t

ion. om

r vital species from the environment or the introduction of a new technology ibut f r t cannot (Postman, 1993). It is possible to cite numerous other examples that involve r at not

o sociocultural as well as technological systems. While we cannot anticipate all f the effects that might arise from some new technology or methodology, we

however, certainly should give far more thought to some of the arcane possibilities. It is version ng,

t impossible to imagine that the first humans who could create and control fire paper book, at ive could have foreseen even a few of the simple, practical applications of the at rm o fireplace and the forge. They certainly had experienced the ravages of fire. riginal horit ic f

o However, in the not-distant past the scientists who developed the first nuclear e h pile clearly understood the potential of the nuclear bomb as a devastating t he aut t weapon of destruction. om r as ing-specif t ion ed f peset

y DISCUSSION publicat

her t Engineering, together with technology, is the day-to-day driving force that iles creat is h t

L f shapes our destiny (Russell, 1953). It creates the overall infrastructure and in

M of

and ot time evolves as the reflection of our detailed human character. In fact, as we X have said in the past, the infrastructure is us. It expresses the history of our lives om yles, r f and the technological and social evolution of humankind through its various st version societies. More pointedly it reminds us that we are what we were and will be print posed

e what we are. To quote more precisely, h heading

recom We should not allow the infrastructure to develop only on the basis of use t individual utility and short-term measures of cost and benefit, or narrowly breaks,

ease measurable attributes that are tractable with current analytic tools. We require l been P longer-range goals of a creative and inspirational kind that blend technological word has ed. and aesthetic considerations. The future of quality of life is to some hs, considerable degree in our hands when we debate decisions about

insert infrastructure. Are beautiful structures ever obsolete? (Herman and Ausubel,

ally 1988, p. 21) line lengt original work e

h It is clear that we must somehow generate a social imperative that will t provide inspirational leadership so that our society can strive to reach the

he original; highest quality of life with integrity and equality. In this regard it is important ion of t at o once and for all to turn to the question of how much it costs society as a whole

ue t that there exists a significant level of legal, moral, and ethical criminality over a r have been accident y t

a wide spectrum at all levels. We have been surprised to find that when this represent m are

l question is raised it appears to be essentially taboo in our culture. However, the a central issue of this volume, engineering within ecological constraints, cries out errors to have precisely such questions scrutinized. It implies that there are goals to be

age breaks set that will in fact improve the quality of life as we go forward with all of our P is new digit human enterprises. There is no question but that this focuses on deep h pographic y iles. T t philosophical issues. It is not our purpose here to delve into the details but

f e ile:

ng rather to raise the issue in the hope that our collective minds might set a course i f t F

D toward what can be done to develop better understanding and subsequently P

peset establish methodologies for improvement. We all know that the failure of a bolt and som is y h t costing a few cents,

ined, a bout A ret original t

ion. om

r whether the result of incompetence or criminality, can cause a disaster, and ibut f r t cannot when the failure is the result of criminality, we need to invent new descriptive r at not

o words since malicious and venal causes are very different from failure arising f from incompetence or random stochastic events.

however, To return to the subject of engineering within ecological constraints, we version ng,

t must remember the importance of science. Science is the wellspring that paper book, at ive provides the knowledge we require to realize our engineering and technological at rm o goals. This is not to say that new pathways have not arisen from applied riginal horit ic f

o research. It is fortunate that early humans were curious about the world around e h them and appreciated the profound value of the knowledge they had acquired. t he aut t Not only does science provide the basic knowledge to solve applied problems, it om r as ing-specif t also generates the philosophical outlook for further exploration and helps us ion ed f appreciate that there is new knowledge beyond the known boundaries. This new peset y knowledge most often comes as the serendipitous result of the curiosity of publicat

her t creative people who have the insight to ask unusual questions that they sense iles creat is h

t are meaningful to probe (Reines, 1993). L f

M of

and ot Engineering within ecological constraints may generate more fundamental X questions than answers. The present administration has set national priorities for om yles, r f scientific research to strengthen industry, protect the environment, improve the st version educational enterprise, create jobs, and the like. These, of course, are lofty goals print posed

e worthy of the attention and effort of our scientific and engineering community. h heading However, we believe the approach must be developed with extreme care to recom

use t maintain the freedom necessary for creativity to flourish, in both the fundamental and applied sciences, and to limit micromanagement of breaks, ease l been

P fundamental science that until now has flourished under a system of freedom to

word

has explore the ''endless frontier." The reason that micromanagement can be so ed.

hs, detrimental, certainly in the case of complex problems, was well expressed by

insert the American poet Brewster Ghiselin (1955) when discussing the creative

ally process: line lengt original work

e It is essential to remember that the creative end is never in full sight at the h t beginning and that it is brought wholly into view only when the process of creation is completed. It is not to be found by scrutiny of the conscious scene, he original;

ion of 1 t because it is never there. at o ue t r have been accident There are those who believe, for example with Starr (1993), that y t a represent m are

l Sustaining and improving the quality of life for a diverse global population a over the next 200 years will not be limited by the availability of resources, in errors spite of the likely massive increases in population and economic demands over this time span. The key resource that makes this possible is science and age breaks

P technology. The supply potentials for food, water, and energy appear adequate is new digit h

pographic even with today's menu of available technologies provided they are fully y iles. T t

e implemented and chosen to minimize environmental degradation. ile: ng i f t F

D Starr goes on to say that "neither science, nor technology, nor politics, nor P peset and som is y religion, nor any ideology is likely by itself to provide the best answers or h t

absolute ined, a bout A ret original t

ion. om

r criteria for governmental actions, either regionally or globally, that would be ibut f r t cannot adequate for two centuries." In contrast, we are well aware that various global r at not

o scenarios put forward by Forrester (1971) as well as by Meadows and others f (1992), have reached conclusions quite different from those of Starr with regard

however, to global well-being based on our present levels of science and technology. version ng,

t More recently, Pimentel and coauthors (1994) have claimed that to spread the paper book, at ive equivalent of Western World quality of life ubiquitously over the entire globe, at rm o the current word population would have to be reduced significantly. These riginal horit ic f

o authors ask, "Does human society want 10 to 15 billion humans living in e h poverty and malnourishment or 1 to 2 billion living with abundant resources t he aut t and a quality environment?" Answers to such profound questions, of course, om r as ing-specif t involve social, religious, political, and philosophical outlooks that probably will ion ed f never come to closure. peset y These differing results are some of many examples that could be cited publicat

her t when considering complex sociotechnical problems whose projections critically iles creat is h t

L f depend on the assumptions that are made and the character of the mathematical

M of

and ot model. It should come as no surprise that there is a difference of opinion among X competent and honest scientists regarding how to address complex problems. It om yles, r f is difficult to find the proper management and encouragement by governmental st version bodies to bring efficiency and understanding into such considerations. The print posed

e overall politicization and often unrealistic promises of our scientific and h heading technical enterprise cannot be of long-term benefit to any one. recom

use t How then can we approach the task of addressing the manner in which engineering should proceed within the sensible boundaries of ecology? A breaks, ease l been

P democracy will always have myriad discussions of any issue on technical,

word

has social, and political levels. This is especially true when decisions must be made ed.

hs, regarding the allocation of resources. However, science is the fountainhead of

insert new knowledge. If we must prove in advance that all of our inquiries will be

ally productive or even sensible, the greatest drying forces for science will be line lengt frustrated. So-called pure research is risky, rarely efficient. Yet it is the solution original work e h

t to individual fundamental problems that makes possible great advances in science and mathematics with consequent disciplinary and social value for the he original;

ion of future. t at o We are all very familiar with the intense scrutiny received by new ideas ue t r have been accident and results, especially if they are disjoint with respect to conventional wisdom y t a and especially so if the work is perceived to have importance. As a rule this is a represent m are

l healthy competitive process, although some of the resistance comes from the a conservative nature of the technical communities; and, of course, there is the errors not-invented-here syndrome.

age breaks An interesting example of the impact of governmental thinking on science P is new digit

h and technology is Thomas Jefferson's concern with social utility when the pographic y iles. T t

f United States was very young (Martin, 1952). In 1800 Jefferson organized a e ile: ng i f rank ordering of the utility of the sciences for Joseph Priestley. The list was t F

D headed by botany and chemistry, with natural philosophy, mathematics, and P peset and som is astronomy in y h t

ined, a bout A ret original t

ion. om

r the middle of the list, and the fine arts at the end. He had an especially high ibut f r t cannot regard for chemistry as one of the most useful sciences with great potential for r at not

o future discoveries, and he expressed the opinion that agriculture was the most f useful of the sciences for America. He qualified his recommendation for

however, geology because he felt its conclusions were uncertain and that it had no version ng,

t obvious utility, but he certainly showed a keen interest in mineral exploration. paper book, at ive However, regarding the branch of knowledge that deals with the formation and at rm o history of the earth, he wrote as follows: riginal horit ic f o e

h The dreams about the modes of creation, inquiries whether our globe has been t he aut t

formed by the agency of fire or water, how many millions of years it has cost om r as ing-specif Vulcan or Neptune to produce what the fiat of the Creator would effect by a t ion

ed f simple act of will, is too idle to be worth a single hour of any man's life. peset y Jefferson went so far as to remark that it made little difference whether the publicat her t earth is 600 or 6,000 years old. We mention these thoughts because in Jefferson iles creat is h t L f we have an example of a true Renaissance genius focusing on practical benefits M of

and ot for valid reasons but with a somewhat less than open mind regarding the value X of improbable fluctuations from which important knowledge does frequently om yles, r f st version arise. Perhaps we can be sympathetic to Jefferson's outlook since in those early days of our country there were not sufficient resources and time to indulge in print posed

e what might have appeared to be the luxury of theoretical speculation. We are h heading now living in a mature sociotechnical culture, and if we were to support only recom

use t those works which appeal because we see pragmatic results, we had better

breaks, beware. Nobody is sufficiently prescient to know where new important ease l been

P developments may lie, and we surely must shun an outlook that smothers

word has

ed. human receptivity to new thoughts and pathways. hs, All of us, especially those in positions of power and control over resources,

insert should take careful note of some of these ideas so beautifully and succinctly

ally expressed by Leonardo da Vinci in his notebooks: line lengt original work e

h Those who fall in love with practice without science are like a sailor who t enters a ship without a helm or a compass and does not know whither he is going .... Science is the captain, practice the soldiers .... All sciences are vain he original; ion of t at o and full of errors that have not been born by experience, mother of all certainty, and that are not tested by experience. ue t r have been accident y t a To return again to our central theme, we might propose that the title of the represent m are

a workshop on which this volume is based could just as well have been, errors

"Engineering Within Ecological and Scientific Constraints." Engineering, which is the day-to-day expression of human activity in advancing the overall

age breaks infrastructure, should proceed in such a way that at a minimum it is essentially P is new digit h

pographic compatible with the best scientific understanding of the time and, in addition, y iles. T t

e takes into account the existing social mores and philosophical and ethical ile: ng i f t outlook of the particular socioculture. It is difficult to ignore the educational F

D enterprise in such considerations. We desperately need new young people P peset and som is y properly trained across disciplines h t

ined, a bout A ret original t

ion. om

r to carry out engineering research within the constraints of ecology. Apart from ibut f r t cannot any specific training, it is imperative that our education system mainly r at not

o encourages students to focus on learning how to learn, learning how to use what f they know, to have a sense of the ethical dilemmas, to view information for

however, what it is, and to appreciate the meaning of understanding and knowledge. Our version ng,

t education system is flawed in that it stresses information and prescriptive paper book, at ive learning, providing students with a "bag of tricks," the value of which decays at rm o rapidly. In our ever-advancing high-technology society, we will be faced with riginal horit ic f

o problems of ever-increasing complexity that will require lifelong development e h in order that we acquire the judgment necessary to make any substantial inroads t he aut t into problems of critical importance to society and the individual as well. om r as ing-specif t Our eternal struggle for new knowledge that on the one hand adds to the ion ed f inner core of our understanding and on the other has useful consequences for peset y humanity requires a great and constant effort as well as a high level of devotion. publicat

her t This is an extremely difficult task since as the ancient Greek philosopher iles creat is h t

L f Heraclitus said, "Nature seeks to hide." Science is not an isolated pursuit, it is

M of

and ot embedded in society and intertwined with all knowledge, especially X engineering, and all of human experience. Science as we know it, which has om yles, r f been the creative Aladdin's lamp for humanity, would not be possible if it were st version not for our deepest conviction both as individuals and as a society that the print posed

e pursuit of science is a great and uplifting endeavor, essential and relevant to h heading both our material and spiritual evolution. We believe that it is mainly through recom

use t science coupled with technology that we will eventually learn how to tackle the extremely complex problems that we have been discussing and whose solution breaks, ease l been

P is so vital for human progress.

word

has In conclusion we feel impelled to state that we are fully cognizant of the ed.

hs, importance of solving practical and timely problems that focus on our daily

insert well-being. Nobody would deny the significance of improving the quality of life

ally for all humans everywhere and at the same time living peacefully with one line lengt another and with nature. Moreover, we must face the Herculean task of original work e h

t conducting our local engineering enterprises in the face of an almost impossibly complex global problem and doing the best we know how at the time. However, he original;

ion of on the other hand, we must never forget that on the long time scale we must t at o continue our striving for the knowledge that comes from all the sciences and, ue t r have been accident when coupled with philosophical and ethical principles, is the key to our y t a continued evolution and freedom. How better to say this than to paraphrase represent m are

l Socrates, who more than two millennia ago said a errors We must rise above the Earth to the top of the atmosphere and beyond, for only then will we fully understand the world in which we live. age breaks P is new digit h pographic y iles. T t

f ACKNOWLEDGMENTS e ile: ng i f t

F I wish to express my deep appreciation to Dr. Ruth A. Reck and to Dr. D

P Shekhar Govind for many interesting and useful discussions that were significant peset and som is y h t

ined, a bout A ret original t

ion. om

r in the structuring of this essay. Thanks are also due Mr. Umer Yousafzai for his ibut f r t cannot assistance in the preparation of this manuscript. r at not o f NOTE however, version ng,

i t

paper book, 1. Another difficulty for the scientist or any creative artist has been most elegantly expressed by at ive at

rm Gertrude Stein (1969, p. 9) in her own inimitable manner: o riginal horit ic f

o One does not ever understand, before they are completely created, what is e h

t happening and one does not at all understand what one has done until the he aut t

om moment when it is all done. Picasso said once that he who created a thing is r as ing-specif t forced to make it ugly. In the effort to create the intensity and the struggle to ion ed f create this intensity, the result always produces a certain ugliness, those who peset

y follow can make of this thing a beautiful thing because they know what they

publicat are doing, the thing having already been invented, but the inventor because he her t iles creat is does not know what he is going to invent inevitably the thing he makes must h t L f have its ugliness. M of

and ot X om yles, r f REFERENCES st version Ayres, R. 1989. Industrial metabolism. Pp. 23-49 in Technology and Environment, J. H. Ausubel print posed

e and H. E. Sladovich, eds. Washington, D.C.: National Academy Press. h

heading Catling, I., ed. 1993. Advanced Technology for Road Transport: IVHS and ATT. Boston, Mass.:

recom Artech House.

use t Forrester, J. W. 1971. World Dynamics. Cambridge, Mass.: Wright-Allen Press.

breaks, Frosch, R. A. 1993. An approach to scenarios of the future industrial ecology. Paper presented at a ease l been Conference on Technological Trajectories and the Human Environment, The Rockefeller P University, New York, October 28-29, 1993. word has ed. Ghiselin, B. 1955. Introduction. P. 21 in The Creative Process: A Symposium, B. Ghiselin, ed. New hs, York: New American Library.

insert Herman, R. 1992. Technology, human interaction, and complexity: Reflections on vehicular traffic science. Operations Research 40(2):199-212. ally Herman, R., and J. H. Ausubel. 1988. Cities and infrastructure: Synthesis and perspectives. Pp. 1-21 line lengt

original work in Cities and Their Vital Systems: Infrastructure Past, Present, and Future. Washington, e

h D.C.: National Academy Press. t Herman, R., and I. Prigogine. 1979. A two-fluid approach to town traffic. Science 204:148-151. ITS America. 1995. National ITS Program Plan: Intelligent Transportation Systems, Volumes I he original;

ion of and II, G. W. Euler and H. D. Robertson, eds. Washington, D.C.: ITS America. t at o IVHS America. 1992. Strategic Plan for Intelligent Vehicle-Highway Systems in the United States. Johnson, E.W. 1993. Avoiding the Collision of Cities and Cars: Urban Transportation Policy for the ue t r have been accident y

t Twenty-First Century. Report on a study project sponsored by the American Academy of a Arts and Sciences in cooperation with the Aspen Institute. Chicago, Ill.: American represent m are

l Academy of Arts and Sciences. a Martin, E.T. 1952. Thomas Jefferson: Scientist. New York: Abelard-Schuman. errors

Meadows, D. H., D. L. Meadows, and J. Rander. 1992. Beyond the Limits: Confronting Global Collapse, Envisioning a Sustainable Future. Post Mills, Vt.: Chelsea Green Publishing

age breaks Company.

P Passent, D. 1994. Pricing the works of nature. World Paper, March, p. 11. is new digit h

pographic Pimentel, D., R. Harmon, M. Pacenza, J. Pecarsky, and M. Pimentel. 1994. Natural resources and an y iles. T t

f optimum human population. Population and Environment: A Journal of Interdisciplinary e ile:

ng Studies 15(5)(May):347-369. i f t

F Postman, N. 1993. Technopoly: The Surrender of Culture to Technology. New York: Random House. D P peset and som is y h t

ined, a bout A ret original t

ion.

om Reines, F. 1993. Who needs science? Technology Transfer Special Issue, Beam Line, Stanford r ibut f r Linear Accelerator Center, Spring:3-5. t cannot Russell, B. 1953. The Impact of Science on Society. New York: Simon and Schuster. r at not

o Starr, C. 1993. On sustainability and the human environment: The next 200 years. Paper presented f at a Conference on Technological Trajectories and the Human Environment, The Rockefeller University, New York, October 28-29, 1993. however, Stein, G. 1969. Picasso. Boston: Beacon Press. version ng,

t Tenner, E. 1991. Revenge Theory. Princeton Alumni Weekly, October 23. paper book, at ive U.S. Congress, Office of Technology Assessment. 1992. Green Products by Design: Choices for a at rm Cleaner Environment. Office of Technology Assessment, OTA-E-54, October. o

riginal Washington, D.C.: U.S. Government Printing Office. horit ic f

o Whelan, R. 1995. Smart Highways, Smart Cars. Boston, Mass.: Artech House. e

h Zuckermann, W. 1991. End of the Road: The World Car Crisis and How We Can Solve It. Post t he aut t

Mills, Vt.: Chelsea Green Publishing Company. om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html DESIGNING SUSTAINABLE ECOLOGICAL ECONOMIC SYSTEMS 79 e h t be

ion. om r ibut f r t cannot r at not Designing Sustainable Ecological o f Economic Systems however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Robert Costanza t he aut t

om r as ing-specif t DEFINING SUSTAINABILITY ion ed f peset

y There is a huge amount of discussion in the literature these days about how

publicat one "defines" sustainability, sustainable development, and related concepts (see her t iles creat is

h Costanza, 1991; Pezzey, 1989; World Commission on Environment and t L f

M of Development, 1987). Many argue that the concept is useless because it cannot

and ot X be "adequately defined." Most of this discussion is misdirected because it (1) om yles, r

f attempts to cast the problem as definitional, when in fact it is a problem of st version prediction, and (2) fails to take into account the many time and space scales

print over which the concept must apply. posed e h

heading Defining sustainability is actually quite easy: a sustainable system is one

recom that survives for some specified (non-infinite) time. The problem is that one use t knows one has a sustainable system only after the fact. Thus, what usually pass breaks, ease l been for definitions of sustainability are actually predictions of what set of conditions P will actually lead to a sustainable system. For example, keeping harvest rates word has ed.

hs, below rates of natural renewal should, one could argue, lead to a sustainable system for extracting natural resources—but that is a prediction, not a insert definition. We know if the system actually is sustainable only after we have had ally

line lengt the time to observe whether the prediction holds. Usually there is so much original work

e uncertainty in our ability to estimate natural rates of renewal and our ability to h t observe and regulate harvest rates that a simple prediction such as this is, as Ludwig et al. (1993) correctly observe, always highly suspect. he original; ion of t at o Likewise, sustainable economic development can only be observed after

ue t the fact. Most "definitions" of sustainable development, encompassing elements r have been accident y t

a of (1) a sustainable scale of the economy relative to its ecological life-support represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r system, (2) a fair distribution of resources and opportunities between present ibut f r t cannot and future generations, as well as between agents in the current generation, and r at not

o (3) an efficient allocation of resources that adequately accounts for natural f capital, are thus really predictors of sustainability and not really elements of a

however, definition. Like all predictions, they are uncertain and are subject to much version ng,

t discussion and disagreement. paper book, at ive The second problem is that when one says a system has achieved sustain- at rm o ability, one does not mean an infinite life span, but rather a life span consistent riginal horit ic f

o with its time and space scale. Figure 1 indicates this relationship by plotting a e h hypothetical curve of system life expectancy on the y axis as a function of time t he aut t

om and space on the x axis. We expect a cell in an organism to have a relatively r as ing-specif t short life span, the organism to have a longer life span, the species to have an ion ed f even longer life span, and the planet to have a longer life span. But no system peset y (even the universe itself in the extreme case) is expected to have an infinite life publicat

her t span. A sustainable system in this context is thus one that attains its full iles creat is h

t expected life span. L f

M of

and ot Individual humans are sustainable by this definition if they achieve their X normal life span. At the population level, average life expectancy is often used om yles, r f as an indicator of health and well-being of the population, but the population st version itself is expected to have a much longer life span than any individual and would print posed

e not be h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

FIGURE 1 Sustainability as scale (time and space) dependent concepts. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r considered to be sustainable if it were to crash prematurely, even if all the ibut f r t cannot individuals in the population were living out their full ''sustainable" life spans. r at not

o Since ecosystems experience succession as a result of changing climatic f conditions and internal developmental changes, they too have a limited (albeit

however, fairly long) life span. The key is differentiating between changes due to normal version ng,

t life span limits and changes that cut short the life span of the system. Things paper book, at ive that cut short the life span of humans are obviously contributors to poor health. at rm o Cancer, AIDS, and a host of other ailments do just this. Human-induced riginal horit ic f

o eutrophication in aquatic ecosystems causes a radical change in the nature of the e h system (ending the life span of the more oligotrophic system while beginning t he aut t the life span of a more eutrophic system). We would have to call this process om r as ing-specif t "unsustainable" using the above definitions since the life span of the first ion ed f system was cut "unnaturally" short. It may have gone eutrophic eventually, but peset y the anthropogenic stress caused this transition to occur "too soon.'' publicat

her t Sustainability is thus most accurately viewed as a long-term goal over iles creat is h t

L f which there is broad and growing consensus. Establishment of this goal is

M of

and ot fundamentally a social decision about the desirability of a survivable ecological X and economic system. Defining sustainability as a goal is relatively om yles, r f straightforward— we want the system to last as long as possible (remembering st version that it is necessary to specify the time and space scale for the system in order to print posed

e interpret "as long as possible"). The real problems are not so much defining the h heading goal as they are predicting what policies will lead to its achievement. Here there recom

use t is ample room for, and need of, vigorous discussion, debate, analysis, and modeling to determine which policies have the best chance of achieving the goal. breaks, ease l been P

word has ed. ECOSYSTEMS AS SUSTAINABLE, NONPOLLUTING hs, PRODUCERS insert

ally Ecological systems play a fundamental role in supporting life on Earth at line lengt all hierarchical scales. They form the life-support system without which original work e h

t economic activity would not be possible. They are essential in global material cycles, such as the carbon and water cycles. They provide raw materials, food, he original;

ion of water, recreation opportunities, and microclimate control for the entire human t at o population. In the long run a healthy economy can exist in symbiosis only with ue t r have been accident a healthy ecology. The two are so interdependent that isolating them for y t a academic purposes has led to distortions and poor management. represent m are

l Ecological systems are also our best current models of sustainable systems. a Better understanding of ecological systems and how they function and maintain errors themselves can yield insights into designing and managing sustainable

age breaks economic systems. For example, there is no "pollution" in mature ecosystems— P is new digit

h all waste and by-products are either recycled and used somewhere in the system pographic y iles. T t

f or they are fully dissipated. "Pollution" is defined as material or energy that is a e ile: ng i f by-product of the activity of one part of the system that has an unintentional t F

D disruptive effect on another part of the system. Some activities such as P peset and som is predation or the scent of a y h t

ined, a bout A ret original t

ion. om

r skunk intended to drive away predators are intentionally disruptive, so these are ibut f r t cannot not pollution by the above definition. In general the lower the entropy of the r at not

o pollution (the higher its organization), the more potentially disruptive it can be. f On the other hand, some forms of pollution (i.e., anthropogenic CO2 emissions)

however, are fairly high in entropy per unit emitted, but the sheer volume can be enough version ng,

t to cause major problems. The disruptive potential of a given pollutant can be paper book, at ive thought of as the product of the quantity of production and its organization at rm o (negative entropy) per unit. riginal horit ic f

o This implies that a characteristic of sustainable economic systems should e h be a similar "closing the cycle" by finding productive uses and recycling t he aut t

om currently discarded "pollution," rather than simply storing it, diluting it, or r as ing-specif t changing its state and allowing it to disrupt other existing ecosystems and ion ed f economic systems that cannot effectively use it. Those things that have no peset y possible productive uses should not be produced at all. publicat

her t Ecosystems have had countless eons of trial and error to evolve these iles creat is h t

L f closed, nonpolluting loops. Early in the earth's history there was certainly

M of

and ot pollution in natural systems, and even today, early successional ecosystems X have pollution under our definition. A general characteristic of closing the loops om yles, r f and building organized nonpolluting natural systems is that the process can take st version a significant amount of time. The connections in the system must evolve, and print posed

e there are characteristics of systems that enhance and retard evolutionary h heading change. Humans have the special ability to perceive this process and potentially recom

use t to enhance and accelerate it. The first pollutant was probably oxygen, an unintentional by-product of breaks, ease l been

P photosynthesis that was very disruptive to anaerobic respiration. There was so

word

has much of this "pollution" that the earth's atmosphere eventually became saturated ed.

hs, with it and new species evolved that could use this former pollution as a

insert productive input in aerobic respiration. The current biosphere represents a

ally balance between these processes—a balance that has evolved over millions of line lengt years to ensure that the formerly unintentional by-product is now an absolutely original work e h

t integral component of the system. Eutrophication and toxic stress are two current forms of pollution that can he original;

ion of be seen as resulting from the inability of the affected systems to evolve fast t at o enough to convert the "pollution" into useful products and processes. ue t r have been accident Eutrophication is the introduction of high levels of nutrients into formerly y t a lower nutrient systems. The species of primary producers (and the assemblages represent m are

l of animals that depend on them) that were adapted to the lower nutrient a conditions are outcompeted by faster-growing species adapted to the higher errors nutrient conditions. But the shift in nutrient regime is so sudden that only the

age breaks primary producers are changed and the result is a disorganized collection of P is new digit

h species with much internal disruption (i.e., plankton blooms, fish kills) that can pographic y iles. T t

f rightly be called pollution. The introduction of high levels of nutrients into a e ile: ng i f system not adapted to them causes pollution (called eutrophication in this case), t F

D whereas the P peset and som is y h t

ined, a bout A ret original t

ion. om

r introduction of the same nutrients into a system that is adapted to them (i.e., ibut f r t cannot marshes and swamps) would be a positive input. We can minimize pollution by r at not

o finding the places in the system where it represents a positive input and placing f it there.

however, Toxic chemicals represent a form of pollution because there are no version ng,

t existing natural systems that have ever experienced them, so there are no paper book, at ive existing systems to which they represent a positive input. The places where at rm o toxic chemicals can most readily find a productive use are probably in other riginal horit ic f

o industrial processes, not in natural ecosystems. The solution in this case is to e h encourage the evolution of industrial processes that can use toxic wastes as t he aut t productive inputs, or, if these cannot be found, to eliminate their production and om r as ing-specif t replace them with alternatives that do have positive uses. ion ed f peset y The Role of Diversity and Organization publicat her t iles creat is h t

L f One strategy that natural systems have evolved to cope with pollution is

M of

and ot diversity. The most disruptive pollutants are relatively low entropy. Low- X entropy matter and energy also represent a potential resource. Given enough om yles, r f time, a species will evolve to take advantage of this potential. Thus, diversity st version may be linked to efficiency at the system level. A higher diversity system print posed

e wastes fewer potentially productive resources by taking advantage of all the h heading "pollution." Early successional systems with low diversity are wasteful of recom

use t resources in the name of rapid growth and colonization. Later successional systems recycle more, close more of the loops, and require higher diversity to breaks, ease l been

P do this. A possible analogy in economic systems is competitive markets. To be

word

has "competitive" and efficient, markets must have a large and diverse set of ed.

hs, participants. Monopolies can get the big jobs done,. but without diversity the

insert system does not satisfy all the smaller product niches and is less efficient at

ally producing what it does produce. line lengt But it is not simply the diversity of species that is important to minimizing original work e h

t pollution, it is how that diversity is organized into a coherent whole system. The degree of organization of a system is contained in the network of interactions he original;

ion of between the component parts (Ulanowicz, 1980, 1986). This means that t at o diversity is a necessary component for minimizing pollution, but it is not ue t r have been accident sufficient. The parts must also be organized so that the waste products from one y t a process are productive inputs to other processes (Allenby and Richards, 1994). represent m are

l a errors Energy, Entropy, Organization, and Embodied Energy

age breaks Economists often think of energy as a commodity (i.e., oil, gas, coal) rather P is new digit

h than as a property (the ability to do work), which is a characteristic of all pographic y iles. T t

f commodities. Discussing the substitutability of energy for other factors of e ile: ng i f production makes sense if energy is a commodity, but not if it is a property of t F

D all commodities. P peset and som is y h t

ined, a bout A ret original t

ion. om

r The first law of thermodynamics tells us that energy and matter are ibut f r t cannot conserved. But this refers to heat energy and mechanical work (call it raw r at not

o energy or the bomb calorimeter energy), not to the useful part of the energy. f The ability to do work is in general related to the degree of organization or

however, order of a thing, the amount of information stored in it, not its raw energy version ng,

t content. Heat must be organized as a temperature gradient between a high- paper book, at ive temperature source and a low-temperature sink before useful work is possible. at rm o Likewise, complex organized structures like cars or books have an ability to do riginal horit ic f

o work that is not related to their raw energy content, but is related to their degree e h of organization. Pollution, too, has an ability to do work (albeit unwanted, t he aut t destructive work) that is proportional to its degree of organization. om r as ing-specif t The second law of thermodynamics tells us that useful energy ion ed f (organization) always dissipates (entropy or disorder always increases) in an peset y isolated system, and to maintain organized structures (like trees, cars, books, publicat

her t and, in general, natural and man-made capital), one must constantly add energy iles creat is h t

L f from outside the system.

M of

and ot But how does one measure the degree of organization of complex X structures? Information theory holds some promise in this regard, but it has yet om yles, r f to live up to its potential. One way to approximate the degree of organization of st version complex structures is to calculate the amount of raw energy it takes, directly print posed

e and indirectly, to build and maintain them. To do this, one must look at the h heading complex web of interconnected production processes that are ecological and recom

use t economic systems. Ecology is often defined as the study of the relationships between breaks, ease l been

P organisms and their environment. The quantitative analysis of interconnections

word

has between species and their abiotic environment has therefore been a central ed.

hs, issue. The mathematical analysis of interconnections is also important in several

insert other fields. Practical quantitative analysis of interconnections in complex

ally systems began with the economist Wassily Leontief (1941) using what has line lengt come to be called input-output (I-O) analysis. More recently, these concepts, original work e h

t sometimes called the materials balance approach, or flow analysis, have been applied to the study of interconnections in ecosystems (Costanza and Neill, he original;

ion of 1984; Finn, 1976; Hannon, 1973, 1976, 1979; Harmon et al., 1991). Related t at o ideas were developed from a different perspective in ecology, under the heading ue t r have been accident of compartmental analysis (Barber et al, 1979; Funderlic and Heath, 1971). y t a Isard (1972) was the first to attempt combined ecological economic system represent m are

l analysis using input-output methods. We refer to the total of all variations of the a analysis of ecological or economic networks as network analysis. errors Network analysis holds the promise of allowing an integrated quantitative

age breaks treatment of combined ecological economic systems. One promising route is the P is new digit

h use of "ascendancy" (Ulanowicz, 1980, 1986) and related indices (Wulff et al., pographic y iles. T t

f 1989) to measure the degree of organization in ecological, economic, or any e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r other networks. Measures like ascendancy go several steps beyond the ibut f r t cannot traditional diversity indices used in ecology. They estimate not only how many r at not

o different species there are in a system but, more important, how those species f are organized. This kind of measure may provide the basis for a quantitative and

however, general index of system organization applicable to both ecological and version ng,

t economic systems. paper book, at ive Another promising avenue of research in network analysis has to do with at rm o its use for "pricing" commodities (both productive commodities and pollution) riginal horit ic f

o in ecological or economic systems. The "mixed units" problem arises in any e h field that tries to analyze interdependence in complex systems that have many t he aut t

om different types and qualities of interacting commodities. Ecology and r as ing-specif t economics are two such fields. Network analysis in ecology has avoided this ion ed f problem in the past by arbitrarily choosing one commodity flowing through the peset y system as an index of interdependence (i.e., carbon, enthalpy, nitrogen, etc.). publicat

her t This ignores the inter-dependencies between commodities and assumes that the iles creat is h

t chosen commodity is a valid "tracer" for relative value or importance in the L f

M of

and ot system. This assumption is unrealistic and severely limits the X comprehensiveness of an analysis whose major objective is to deal om yles, r f comprehensively with whole systems. st version There are evolving methods for dealing with the mixed units problem print posed

e based on analogies to the calculation of prices in economic input-output models. h heading Starting with a more realistic commodity by process description of ecosystem recom

use t networks, which allows for joint products, one can calculate ecological interdependence factors (EIFs) to convert the multiple commodity description breaks, ease l been

P ultimately into a pair of matrices that can serve as the input for standard (single-

word

has commodity) network analysis. The new single-commodity description ed.

hs, incorporates commodity and process interdependencies in a manner analogous

insert to the way economic value incorporates production interdependencies in

ally economic systems (Costanza and Hannon, 1989). This analysis allows the line lengt degree of organization of commodities in the system to be approximated as their original work e h

t direct and indirect energy cost, or embodied energy. To the extent that "organization" so defined is correlated with economic value,1 this approach may he original;

ion of allow valuation of components of combined ecological and economic systems t at o without resorting to subjective evaluations, which are inherently limited when ue t r have been accident applied to ecological commodities. y t a Ecological networks evolve to use the low-entropy, high-embodied-energy represent m are

l by-products of processes in positive, productive ways. Economic systems may a also evolve in this general direction, but we may wish to accelerate the errors evolutionary process to minimize the costs and disruptions inherent in trial and

age breaks error. In addition, some of the possible "trials" could lead to destruction of our P is new digit

h species, and we would not want to risk that. There are several problems and pographic y iles. T t

constraints that limit this accelerated but informed economic evolution. To f e ile: ng i f develop sustainable, nonpolluting ecological economic systems, we need to t F

D understand and remove these constraints. P peset and som is y h t

ined, a bout A ret original t

ion. om

r PROBLEMS AND CONSTRAINTS OF ECONOMIC ibut f r t cannot EVOLUTION r at not o

f Human beings, like all other animals, make decisions based on responses to local, immediate reinforcements. They follow their noses, with some however,

version mediation by genetic (and in the case of humans and some other species ng,

i t paper book, at ive cultural) programming. To understand the human population problem, one at rm needs to understand how this complex of local reinforcements and programmed o riginal horit

ic f responses interacts over several different time scales with the ecosystem within o

e which humans are embedded. h t he aut

t Biological evolution has a built-in bias toward the long run. Changing the

om r as ing-specif genetic structure of a species requires that characteristics (phenotypes) be t ion

ed f selected and accumulated by differential reproductive success. Characteristics peset

y learned or acquired during the lifetime of an individual cannot be passed on genetically. Biological evolution is therefore an inherently slow process publicat her t iles creat is requiring many generations to significantly alter a species' physical h t L f characteristics or behavior. Of course if the species goes through many M of

and ot

X generations rapidly (like bacteria or fruit flies), then the real time required for om yles,

r evolution can be much shorter than for slow-breeding species. Larger, slow- f st version growing species inherently take more time to evolve genetically than small, fast- growing ones. print posed e

h Cultural evolution is much faster than genetic evolution for large, slow- heading growing species like humans, and in recent years it has accelerated to recom use t hyperspeed. Learned behaviors that are successful can be almost immediately breaks,

ease spread to other members of the culture and passed on in the oral, written, or l been P video record. The increased speed of adaptation that this process allows has word has ed. been largely responsible for Homo sapiens' amazing success at controlling the hs, resources of the planet. For example, Vitousek and coauthors (1986) estimate insert that humans now directly control 25 to 40 percent of the planer's primary ally

line lengt production. But there is a significant downside. Like a car that has picked up original work

e speed, we are in much more danger of running off the road or over a cliff. h t

Human activity is beginning to have an effect on global climate and the planet's protective ozone shield. We have lost the built-in, long-run bias of biological he original; ion of t

at evolution and are susceptible to being led by our hyperefficient short-run o adaptability over a cliff into the abyss. ue t r have been accident y t a represent m are

l Social Traps a errors This process of short-run incentives becoming out of sync with long-term goals has been well studied in the last decade under several rubrics (Axelrod, age breaks

P 1984; Hardin, 1968), but the one I like best is John Platt's notion of "social is new digit h pographic

y traps" (Brockner and Rubin, 1985; Costanza, 1987; Cross and Guyer, 1980; iles. T t

f e

ile: Platt, 1973; Teger, 1980). In all such cases the decision maker may be said to be ng i f t

F trapped by the local conditions into making what turns out to be a bad decision D viewed from a longer or wider perspective. We go through life making P peset and som is y

h decisions about which path to take based largely on "road signs," the short-run, t

ined, local reinforcements that a bout A ret original t

ion. om

r we perceive most directly. These short-run reinforcements can include ibut f r t cannot monetary incentives, social acceptance or admonishment, and physical pleasure r at not

o or pain. In general, this strategy of following the road signs is effective, unless f the road signs are inaccurate or misleading. In these cases we can be trapped

however, into following a path that is ultimately detrimental because of our reliance on version ng,

t the road signs. For example, cigarette smoking has been a social trap because paper book, at ive by following the short-run road signs of the pleasure and social status associated at rm o with smoking, we embark on the road to an increased risk of earlier death from riginal horit ic f

o smoking-induced cancer. This particular positive reinforcement has in the last e h few years begun to turn into a negative one. As smoking becomes less socially t he aut t acceptable, we should expect the number of new smokers to fall and many old om r as ing-specif t smokers to escape the trap. But the process of escape is much more difficult ion ed f than the process of avoidance, Once this road has been taken, it is difficult to peset y change to another (as most people who have tried to quit smoking can attest). publicat

her t Pollution is a social trap because the long-term and distributed costs of iles creat is h t

L f pollution (and benefits of not polluting) are not incumbent on the economic

M of

and ot actors in the short run. The speed of cultural evolution has adversely affected X our ability to adequately incorporate the long run. om yles, r f st version The Importance of Uncertainty and How to Deal with It print posed e h heading One key element that has limited our perception of the long run and recom

use t frustrated environmental policy is the enormous degree of uncertainty about long-run human impacts on the biosphere. Ignorance about the consequences is breaks, ease l been

P a particularly effective cause of social traps (Cross and Guyer, 1980).

word

has As regards resources, the environment, and technology, the argument can ed.

hs, be summarized as differing opinions about the degree to which technological

insert progress can eliminate resource constraints and solve pollution problems.

ally Current economic world views (capitalist, socialist, and the various mixtures) line lengt are all based on the underlying assumption of continuing and unlimited original work e h

t economic growth. This assumption allows a whole host of very sticky problems, including population growth, equity, and sustainability to be ignored he original;

ion of (or at least postponed), since they are seen to be most easily solved by t at o additional economic growth. Indeed, most conventional economists define ue t r have been accident "health" in an economy as a constant and high rate of growth. Energy and y t a resource limits to growth, according to these world views, will be eliminated as represent m are

l they arise by clever development and deployment of new technology. This line a of thinking is often called technological optimism. errors An opposing line of thought (often called technological pessimism)

age breaks assumes that technology will not be able to circumvent fundamental energy and P is new digit

h resource constraints and that eventually economic growth will stop. It has pographic y iles. T t

f usually been ecologists or other life scientists who take this point of view e ile: ng i f largely because they study natural systems that invariably do stop growing t F

D when they reach fundamental P peset and som is y h t

ined, a bout A ret original t

ion. om

r resource constraints. A healthy ecosystem is one that maintains a stable ibut f r t cannot condition. Unlimited growth is cancerous, not healthy, under this view. r at not

o The technological optimists argue that human systems are fundamentally f different from other natural systems because of human intelligence. History has

however, shown that resource constraints can be circumvented by new ideas. version ng,

t Technological optimists claim that Malthus's dire predictions about population paper book, at ive pressures have not come to pass and that the "energy crisis" of the late 1970s is at rm o behind us. riginal horit ic f

o The technological pessimists argue that many natural systems also have e h "intelligence" in that they can evolve new behaviors and organisms (including t he aut t

om humans themselves). Humans are therefore a part of nature, not apart from it. r as ing-specif t Just because we have circumvented local and artificial resource constraints in ion ed f the past does not mean we can circumvent the fundamental ones that we will peset y eventually face. Malthus's predictions have not come to pass yet for the entire publicat

her t world, the pessimists would argue, but many parts of the world are in a iles creat is h

t Malthusian trap now, and other parts may well fall into it. L f

M of

and ot This debate has gone on for several decades now. It began with Barnett X and Morse's (1963) Scarcity and Growth and really went into high gear with the om yles, r f publication of The Limits to Growth by Meadows et al. (1972) and the Arab oil st version embargo in 1973. There have been thousands of studies over the last 15 years print posed

e on various aspects of our energy and resource future and different points of h heading view have waxed and waned. But the bottom line is that there is still an recom

use t enormous amount of uncertainty about the impacts of energy and resource constraints, and I doubt that the argument will ever be decided on scientific breaks, ease l been

P grounds.

word

has In the next 20-30 years we may begin to hit real fossil fuel supply limits as ed.

hs, well as constraints on production due to global warming. Will fusion energy or

insert solar energy or conservation or some as yet unthought of energy source step in

ally to save the day and keep economies growing? The technological optimists say line lengt yes and the technological pessimists say no. Ultimately, no one knows. Both original work e h

t sides argue as if they were certain, but the worst form of ignorance is misplaced certainty. he original;

ion of The optimists argue that unless we believe that the optimistic future is t at o possible and behave accordingly it will never come to pass. The pessimists ue t r have been accident argue that the optimists will bring on the inevitable leveling and decline sooner y t a by consuming resources faster and that to sustain our system we should begin to represent m are

l conserve resources immediately. How do we proceed in the face of this a overwhelming uncertainty? errors We can cast this optimist/pessimist choice in a classic (and admittedly

age breaks oversimplified) game theoretic format using the payoff matrix shown in P is new digit

h Figure 2. Here the alternative policies that we can pursue today (technologically pographic y iles. T t

f optimistic or pessimistic) are listed on the left and the real states of the world e ile: ng i f are listed on the top. The intersections are labeled with the results of the t F

D combinations of policies and states of the world. For example, if we pursue the P peset and som is optimistic policy and the world really does turn out to conform to the optimistic y h t

assumptions, then ined, a bout A ret original t

ion. om r ibut f r t cannot Real state of the world r at not o

f Optimists right Pessimists right

however, Current policy Technological optimist policy High Disaster version ng,

i t paper book, at ive Technological pessimist at

rm Moderate Tolerable

o policy riginal horit ic f o

e FIGURE 2 Payoff matrix for technological optimism vs. pessimism. h t he aut t

om r as ing-specif

t the payoffs would be high. This high potential payoff is very tempting and ion ed f this strategy has paid off in the past. It is not surprising that so many would like peset

y to believe that the world conforms to the optimists' assumptions. If, however, we pursue the optimistic policy and the world turns out to conform more closely publicat her t iles creat is to the pessimistic technological assumptions, then the result would be h t L f

of "Disaster." The disaster would come because irreversible damage to ecosystems

and ot

X would have occurred and technological fixes would no longer be possible. om yles, r If we pursue the pessimistic policy and the optimists are right, then the f st version results are only "Moderate." But if the pessimists are right and we have pursued

print the pessimistic policy, then the results are "Tolerable." posed e

h Within the framework of game theory, this simplified game has a fairly heading

recom simple "optimal" strategy. If we really do not know the state of the world and if use t the game is only played once (which is the case at the global level), then we breaks, ease l

been should choose the policy that offers the maximum of the minimum outcomes P (i.e., the MaxiMin strategy in game theory jargon). In other words, we analyze word has ed.

hs, each policy in turn, look for the worst thing (minimum) that could happen if we pursue that policy, and pick the policy with the best worst case. In the case insert stated above, we should pursue the pessimist policy because the worst possible ally

line lengt result under that policy ("Tolerable") is preferable to the worst outcome under original work

e the optimist policy ("Disaster"). h t Given this analysis, what can one recommend for pollution policy? Because of the large uncertainty about the long-term impacts on ecological he original; ion of t at o sustainability, we should at least provisionally assume the worst. We must assume that the dire predictions are correct and plan accordingly. If they are ue t r have been accident y t

a right we will still survive. If they are wrong we will be pleasantly surprised. represent m are This is a much different scenario than the consequences of provisionally

l a assuming the best about the impacts. If we assume the optimists are right and errors they are not, we will have irreversibly degraded the planet's capacity to support life. We cannot rationally take that risk. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r TOWARD A SUSTAINABLE, NONPOLLUTING ibut f r t cannot ECOLOGICAL ECONOMIC SYSTEM r at not o

f How then do we communicate these conclusions to the people who make the decisions--the economic actors--and escape the pollution trap? The however,

version elimination of social traps requires intervention--the modification of the ng,

i t paper book, at ive reinforcement system. Indeed, it can be argued that the proper role of a at rm democratic government is to eliminate social traps (no more and no less) while o riginal horit

ic f maintaining as much individual freedom as possible (Costanza, 1987). Cross o

e and Guyer (1980) list four broad methods by which traps can be avoided or h t he aut

t escaped. These are education (about the long-term, distributed impacts);

om r as ing-specif insurance; superordinate authority (i.e., legal systems, government, religion); t ion

ed f and converting the trap to a trade-off by correcting the road signs. peset

y Education can be used to warn people of long-term impacts that cannot be seen from the road. Examples are the warning labels now required on cigarette publicat her t iles creat is packages and the warnings of environmentalists about future hazardous waste h t L f problems. People can ignore warnings, however, particularly if the path seems M of

and ot

X otherwise enticing. For example, warning labels on cigarette packages have had om yles,

r little effect on the number of smokers. f st version The main problem with education as a general method of avoiding and escaping from traps is that it requires a significant time commitment on the part print posed e

h of individuals to learn the details of each situation. Our current society is so heading large and complex that we cannot expect even professionals, much less the recom use t general public, to know the details of all the extant traps. In addition, for breaks,

ease education to be effective in avoiding traps involving many individuals, all the l been P participants must be educated. word has ed. Governments can, of course, forbid or regulate certain actions that have hs, been deemed socially inappropriate. The problem with this approach is that it insert must be rigidly monitored and enforced, and the strong short-term incentive for ally

line lengt individuals to try to ignore or avoid the regulations remains. A police force and original work

e legal system are very expensive to maintain, and increasing their chances of h t catching violators increases theft costs exponentially (both the costs of maintaining a larger, better-equipped force and the cost of the loss of individual he original; ion of t

at privacy and freedom). o Religion and social customs can be seen as much less expensive ways to ue t r have been accident y t avoid certain social traps. If a moral code of action and belief in an ultimate a represent m

are payment for transgressions can be deeply instilled in a person, the probability of

l a that person's falling into the "sins" (traps) covered by the code will be greatly errors reduced, and with very little enforcement cost. On the other hand, the problems with religion and social customs as means to avoid social traps are that the age breaks

P moral code must be relatively static to allow beliefs learned early in life to is new digit h pographic remain in force later, and it requires a relatively homogeneous community of y iles. T t

f e

ile: like-minded individuals to be truly effective. This system works well in ng i f t

F culturally homogeneous D P peset and som is y h t

ined, a bout A ret original t

ion. om

r societies that are changing slowly. In modem, heterogeneous, rapidly changing ibut f r t cannot societies, religion and social customs cannot handle all the newly evolving r at not

o situations or the conflict between radically different cultures and belief systems. f Many trap theorists believe that the most effective method for avoiding

however, and escaping from social traps is to turn the trap into a trade-off. This method version ng,

t does not run counter to our normal tendency to follow the road signs; it merely paper book, at ive corrects the signs' inaccuracies by adding compensatory positive or negative at rm o reinforcements. A simple example illustrates how effective this method can be. riginal horit ic f

o Playing slot machines is a social trap because the long-term costs and benefits e h to the player are inconsistent with the short-term costs and benefits to the t he aut t player. People play the machines because they expect a large short-term om r as ing-specif t jackpot, while the machines are in fact programmed to pay off, say, $0.80 on ion ed f the dollar in the long-term.2 People may ''win'' hundreds of dollars playing the peset y slots (in the short ran), but if they play long enough they will certainly lose publicat

her t $0.20 for every dollar played. To change this trap to a trade-off, one could iles creat is h

t simply reprogram the machines so that every time a dollar was put in $0.80 L f

M of

and ot would come out. This way the short-term reinforcements ($0.80 on the dollar) X are made consistent with the long-term reinforcements ($0.80 on the dollar), om yles, r f and only the dedicated aficionados of spinning wheels with fruit painted on st version them would continue to play. print posed e h heading INNOVATIVE INSTRUMENTS FOR ENVIRONMENTAL recom use t MANAGEMENT breaks, ease l been

P Current command-and-control systems of environmental regulation are not

word

has very efficient at managing environmental resources for sustainability, ed.

hs, particularly in the face of uncertainty about long-term values and impacts. They

insert are inherently reactive rather than proactive. They induce legal confrontation,

ally obfuscation, and government intrusion into business. Rather than encouraging line lengt long-range technical and social innovation, they tend to suppress it. They do not original work e h

t mesh well with the market signals that firms and individuals use to make decisions and do not effectively translate long-term global goals into short-term he original;

ion of local incentives. They do not effectively turn environmental traps into trade-offs. t at o We need to explore promising alternatives to our current command-and- ue t r have been accident control environmental management systems, and to modify existing y t a government agencies and other institutions accordingly. The enormous represent m are

l uncertainty about local and transnational environmental impacts needs to be a incorporated into decision making. We also need to understand better the errors sociological, cultural, and political criteria for acceptance or rejection of policy

age breaks instruments. P is new digit

h One example of an innovative policy instrument currently being studied is pographic y iles. T t

f a flexible environmental assurance bonding system designed to incorporate e ile: ng i f environmental criteria and uncertainty into the market system and to induce t F

D positive environmental technological innovation (Costanza and Perrings, 1990; P peset and som is Perrings, 1989, 1991). y h t

ined, a bout A ret original t

ion. om

r In addition to direct charges for known environmental damages, a ibut f r t cannot company would be required to post an assurance bond equal to the current best r at not

o estimate of the largest potential future environmental damages due to its f activities; the money would be kept in interest-bearing escrow accounts. The

however, bond (plus a portion of the interest) would be returned if the firm could show version ng,

t that the suspected damages had not occurred or would not occur. If they did, the paper book, at ive bond could be used to rehabilitate or repair the environment or to compensate at rm o injured parties. Thus, the burden of proof would be shifted from the public to riginal horit ic f

o the resource-user, and a strong economic incentive would be provided to e h research the true costs of environmentally damaging activities and to develop t he aut t technologies that cause little pollution and provide innovative and cost-effective om r as ing-specif t pollution control. This is an extension of the "polluter pays" principle to "the ion ed f polluter pays for uncertainty as well." peset y In addition, we need to develop innovative instruments to handle publicat

her t transnational pollution problems and the costs of natural resource depletion. iles creat is h t

L f Two suggestions for handling these problems are the system of ecological

M of

and ot tariffs and the natural capital depletion tax mentioned briefly below. X om yles, r f st version CONCLUSIONS print posed

e Balancing the human species in the ecosystem and developing sustainable, h heading nonpolluting ecological economic systems is, in principle, a simple problem. recom

use t Simply make the long-run, distributed, whole-system costs and benefits of human activities, including uncertainty, incumbent on all individuals in the breaks, ease l been

P short run and locally, at least provisionally until the uncertainty can be lowered.

word

has This will greatly accelerate the natural evolutionary processes and force a ed.

hs, "closing of the loops" to happen more quickly. If this whole-system cost

insert accounting (including uncertainty) is in place, we can expect individual

ally decisions about pollution control and resource consumption to help move the line lengt system toward a sustainable and nonpolluting condition. original work e h

t Of course, in principle is very far from in practice in this particular case. The problems of devising cultural mechanisms to effectively communicate he original;

ion of ecological costs to individual actors are daunting. The next stage of our cultural t at o evolution must be the development of just this capacity to put back in the long- ue t r have been accident run constraints that the initial phase of cultural evolution appeared to release us y t a from. We need to develop and use cultural "road maps" and "scouts" to counter represent m are

l our dependence on "road signs'' in the tricky terrain where we now find a ourselves. I offer the following summary suggestions toward the goal of errors developing sustainable, nonpolluting, ecological economic systems.

age breaks 1. Establish a hierarchy of goals for national and global ecological economic P is new digit h

pographic planning and management. Sustainability should be the primary long-term y iles. T t

e goal, replacing the current GNP growth mania. Issues of justice, equity, ile: ng i f t and population are ultimately tied in with sustainability as preconditions. F

D Only sustainable levels of human activity are desirable. Economic growth P peset and som is y in this hierarchy h t

ined, a bout A ret original t

ion. om

r is a valid goal only when it is consistent with sustainability. The goals can ibut f r t cannot be put into operation by having them accepted as part of the political r at not

o debate and implemented in the decision making structure of institutions f that affect the global economy and ecology (for example, the World Bank).

however, 2. Develop better global ecological economic modeling capabilities to allow version ng,

t us to see the range of possible outcomes of our current activities, paper book, at ive especially the interrelated impacts of population, pollution, per capita at rm o resource use, and wealth distribution. riginal horit ic f

o 3. Adjust current incentives to reflect both short- and long-run, local and e h global ecological costs, including uncertainty. To paraphrase the popular t he aut t

om slogan, we should model globally and adjust local incentives accordingly. r as ing-specif t Below I list three broad, mutually reinforcing policy instruments that have ion ed f a high likelihood of ensuring that economic development (as distinct from peset y economic growth) is ecologically sustainable (Costanza, 1994). They use publicat

her t market incentives to produce the desired results (sustainable scale, fair iles creat is h

t distribution, and efficient allocation). These incentives are as follows: L f

M of

and ot a. Ecological tax reform. A natural capital depletion tax aimed at reducing X

om or eliminating the destruction of natural capital would assume more of the yles, r f st version tax burden instead of taxes on labor and income. Use of nonrenewable natural capital would have to be balanced by investment in renewable print posed e natural capital to avoid the tax. The tax would be passed on to consumers h heading in the price of products and would send the proper signals about the recom

use t relative sustainability cost of each product, moving consumption toward a

breaks, more sustainable product mix. This policy will encourage the ease l been P

technological innovation that optimists are counting on while conserving word has

ed. resources in case the optimists are wrong. hs, b. The precautionary polluter pays principle (4P) would be applied to insert potentially damaging products to incorporate the cost of the uncertainty

ally about ecological damages as well as the costs of known damages line lengt

original work (Costanza and Cornwell, 1992; Costanza and Perrings, 1990). This would e h t

give producers a strong and immediate incentive to improve their environmental performance to reduce the size of the environmental bond he original; ion of

t and tax they would have to pay. The 4P approach can allow long-term at o worst-case ecological costs to be made apparent to individual actors in an ue t r have been accident

y efficient and culturally acceptable way. t a c. A system of ecological tariffs aimed at allowing individual countries or represent m are

a trading blocks to apply incentives a and b above without forcing errors

producers to move overseas to remain competitive. Countervailing duties would be assessed to impose fairly the ecological costs associated with

age breaks production on both internally produced and imported products. Revenues P is new digit h

pographic from the tariffs would be reinvested in the global environment, rather than y iles. T t

e added to general revenues of the host country. The ecological tariffs ile: ng i f t should be proportional to the environmental damages that occur anywhere F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r in the world as a by-product of the product's production. They can be ibut f r t cannot unilaterally applied by any country without damaging that country's trade r at not

o balance or economic performance. Countries that do not implement f systems to ensure ecologically benign production would be at a

however, competitive disadvantage since their products will be harder to sell abroad version ng,

t in countries that have ecological tariffs. In other words, the ecological paper book, at ive tariff system would protect local producers of ecologically benign at rm o products as well as discouraging ecologically destructive production riginal horit ic f

o abroad. Once a few large countries implemented the system, the rest of e h the world would be forced to follow suit. t he aut t

om The ecological tariffs, in conjunction with the 4P system and the natural r as ing-specif t capital depletion tax, would provide the appropriate incentives to turn many ion ed f of our current ecological traps into trade-offs and provide the appropriate peset y constraints to lead to a sustainable ecological economic system. publicat her t iles creat is h t L f NOTES M of

and ot X om yles,

r 1. Recent studies (Cleveland et al., 1984; Costanza, 1980; Costanza and Herendeen, 1984; f st version Gever et al., 1986; Hall et al., 1986) indicate that in fact this correlation is surprisingly strong. 2. Slot machines are obviously not a trap for the owners of the machines. print posed e h heading

recom REFERENCES use t Allenby, B. R., and D. J. Richards, eds. 1994. The Greening of Industrial Ecosystems. Washington, breaks, ease l been D.C.: National Academy Press. P Axelrod, R. 1984. The Evolution of Cooperation. New York: Basic Books. word has

ed. Barber, M., B. Patten, and J. Finn. 1979. Review and evaluation of I-O flow analysis for ecological hs, applications. In Compartmental Analysis of Ecosystem Models. Vol. 10 of Statistical Ecology, J. Matis, B. Patten, and G. White, eds. Burtonsville, Md.: International insert Cooperative Publishing House.

ally Barnett, H. J., and C. Morse. 1963. Scarcity and Growth: The Economics of Natural Resource line lengt Availability. Baltimore, Md.: Johns Hopkins. original work

e Brockner, J., and J. Z. Rubin. 1985. Entrapment in Escalating Conflicts: A Social Psychological h t

Analysis. New York: Springer-Verlag. Cleveland, C. J., R. Costanza, C. A. S. Hall, and R. Kaufmann. 1984. Energy and the United States he original;

ion of economy: A biophysical perspective. Science 225:890-897. t at o Costanza, R. 1980. Embodied energy and economic valuation. Science 210:1219-1224. Costanza, R. 1987. Social traps and environmental policy. BioScience 37:407-412. ue t r have been accident

y Costanza, R., ed. 1991. Ecological Economics: The Science and Management of Sustainability. t a New York: Columbia University Press. represent m are

Costanza, R. 1994. Three general policies to achieve sustainability. Pp. 392-407 in Investing in l a Natural Capital: The Ecological Economics Approach to Sustainability, A. M. Jansson, M.

errors Hammer, C. Folke, and R. Costanza, eds. Washington, D.C.: Island Press.

Costanza, R., and L. Cornwell. 1992. The 4P approach to dealing with scientific uncertainty. Environment 34:12-20, 42. age breaks

P Costanza, R., and B. M. Hannon. 1989. Dealing with the "mixed units" problem in ecosystem is new digit h

pographic network analysis. Pp. 90-115 in Network Analysis of Marine Ecosystems: Methods and y iles. T t

Applications. Coastal and Estuarine Studies Series, F. Wulff, J. G. Field, and K. H. Mann, f e ile: eds. Heidleberg: Springer-Verlag. ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Costanza, R., and R. A. Herendeen. 1984. Embodied energy and economic value in the United r ibut f r States economy: 1963, 1967, and 1972. Resources and Energy 6:129-163. t cannot Costanza, R., and C. Neill. 1984. Energy intensities, interdependence, and value in ecological r at not

o systems: A linear programming approach. Journal of Theoretical Biology 106:41-57. f Costanza, R., and C. H. Perrings. 1990. A flexible assurance bonding system for improved environmental management. Ecological Economics 2:57-76. however, Cross, J. G., and M. J. Guyer. 1980. Social Traps. Ann Arbor: University of Michigan Press. version ng,

t Finn, J. 1976. The cycling index. Journal of Theoretical Biology 56:363-373. paper book, at ive Funderlic, R., and M. Heath. 1971. Linear Compartmental Analysis of Ecosystems. ORNL- at rm IBP-71-4. Oak Ridge, Tenn.: Oak Ridge National Laboratory. o

riginal Gever, J., R. Kaufmann, D. Skole, and C. Vörösmarty. 1986. Beyond Oil: The Threat to Food and horit ic f

o Fuel in the Coming Decades. Cambridge, Mass.: Ballinger. e

h Hall, C. A. S., C. J. Cleveland, and R. Kaufmann. 1986. Energy and Resource Quality: The Ecology t he aut t

of the Economic Process. New York: Wiley. om r

as Harmon, B. 1973. The structure of ecosystems. Journal of Theoretical Biology 41:535-546. ing-specif t Hannon, B. 1976. Marginal product pricing in the ecosystem. Journal of Theoretical Biology ion ed f 56:256-267. peset

y Harmon, B. 1979. Total energy costs in ecosystems. Journal of Theoretical Biology 80:271-293. Hannon, B., R. Costanza, and R. Ulanowicz. 1991. A general accounting framework for ecological publicat

her t systems: A functional taxonomy for connectivist ecology. Theoretical Population Biology iles creat is

h 40:78-104. t L f Hardin, G. 1968. The tragedy of the commons. Science 162:1243-1248. M of

and ot

X Isard, W. 1972. Ecologic-Economic Analysis for Regional Development. New York: The Free Press. Leontief, W. 1941. The Structure of American Economy, 1919-1939. New York: Oxford University om yles, r f Press. st version Ludwig, D., R. Hilborn, and C. Walters. 1993. Uncertainty, resource exploitation, and conservation: Lessons from history. Science 260:17, 36. print posed

e Meadows, D. H., D. L. Meadows, J. Randers, and W. W. Behrens. 1972. The Limits to Growth. h

heading New York: Universe.

recom Perrings, C. 1989. Environmental bonds and the incentive to research in activities involving

use t uncertain future effects. Ecological Economics 1:95-110.

breaks, Perrings, C. A. 1991. Reserved rationality and the precautionary principle: Technological change, ease l been time and uncertainty in environmental decision making. Pp. 153-167 in Ecological P Economics: The Science and Management of Sustainability, R. Costanza, ed. New York: word has ed. Columbia University Press. hs, Pezzey, J. 1989. Economic Analysis of Sustainable Growth and Sustainable Development.

insert Environment Department Working Paper No. 15. Washington, D.C.: The World Bank. Platt, J. 1973. Social traps. American Psychologist 28:642-651. ally Teger, A. I. 1980. Too Much Invested to Quit. New York: Pergamon. line lengt

original work Ulanowicz, R. E. 1980. An hypothesis on the development of natural communities. Journal of e

h Theoretical Biology 85:223-245. t Ulanowicz, R. E. 1986. Growth and Development: Ecosystems Phenomenology. New York: Springer-Verlag. he original;

ion of Vitousek, P., P. R. Ehrlich, A. H. Ehrlich, and P. A. Matson. 1986. Human appropriation of the t at o products of photosynthesis. BioScience 36:368-373. World Commission on Environment and Development. 1987. Our Common Future. Oxford: Oxford ue t r have been accident y

t University Press. a Wulff, F., J. G. Field, and K. H. Mann. 1989. Network Analysis of Marine Ecosystems: Methods represent m are

l and Applications. Coastal and Estuarine Studies Series. Heidleberg: Springer-Verlag. a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ECOLOGICAL INTEGRITY AND ECOLOGICAL HEALTH ARE NOT THE SAME 97 e h t be

ion. om r ibut f r t cannot r at not Ecological Integrity and Ecological Health o f Are Not the Same however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h James R. Karr t he aut t

om r as ing-specif t THE FOLLY OF THE STATUS QUO ion ed f peset

y Environmental issues are not merely a concern of extremists; healthy

publicat biological systems are critical to the success, perhaps even survival, of the her t iles creat is

h human species. Although notable progress has been made in a few areas of t L f

M of environmental protection (e.g., agreement to limit CFC releases), current

and ot X planning programs and legislative initiatives are not adequate to protect natural om yles, r

f or human environments. st version The complex reasons for failure center on the hubris of a society that

print behaves as if it could repeal the laws of nature, Plans generated by economists, posed e h

heading technologists, engineers, and ecologists have too often assumed that lost or

recom damaged components of ecological systems are unimportant or can be repaired use t or replaced. We see the consequences of this attitude everywhere. In the Pacific breaks, ease l been Northwest, for example, hatcheries are built to sustain salmonid stocks while P minimal effort is made to restore degraded habitat, reduce excessive harvests, or word has ed.

hs, protect seasonal river flow. Throughout the world, expensive fertilizers are added to replace nutrients in depleted soils. Groundwater is depleted to supply insert unsustainable amounts of water. These and other examples demonstrate the ally

line lengt folly of maintaining the status quo. original work

e Interdisciplinary initiatives seeking to improve environmental policy are h t cropping up in many contexts. These initiatives are driven by goals such as environmental justice (Bullard, 1994), protection of biodiversity (Wilson, he original; ion of t at o 1992), and pollution control (Colborn and Clement, 1992); they are grounded in

ue t concepts such as ecological economics (Costanza, 1991; Jansson et al., 1994), r have been accident y t

a conservation biology (Meffe and Carroll, 1994), and industrial ecology represent m are

(Allenby and l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Richards, 1994; Richards and Fullerton, 1994). A core societal vision should be ibut f r t cannot integrating all these initiatives to protect ecological integrity (Karr, 1993; r at not

o Westra, 1994) and ecological health (Costanza et al., 1992; Rapport et al., f 1994). Ecologists and engineers alike must become more aware of the need to

however, protect biological systems as integral components of human welfare; ecologists version ng,

t as well as engineers must better understand and respond to societal needs. paper book, at ive Failure to do so holds ominous consequences. at rm o riginal horit ic f o

e GROWING ENVIRONMENTAL CONCERNS h t he aut t

om For most of the twentieth century, the most visible demonstration of public r as ing-specif t concern for the environment was the conservation movement in the developed ion ed f world. But voices now coming from all corners of society draw attention to the peset y severity of present ecological crises. A Health of the Planet Survey by the publicat

her t Gallup Organization (Dunlap et al., 1993) asked more than 28,000 individuals iles creat is h

t in 24 countries (including industrialized and developing nations) about their L f

M of

and ot environmental attitudes. The results show "strong public concern for X environmental protection throughout the world, including regions where it was om yles, r f assumed to be absent." st version Scholars too are calling for shifts in human behavior. A worldwide print posed

e collection of 1,575 scientists, including 99 Nobel Prize winners, noted that h heading "human beings and the natural world are on a collision course.... A great change recom

use t in our stewardship of the earth, and life on it, is required if vast human misery is to be avoided and our global home on this planet is not to be irretrievably breaks, ease l been

P mutilated" (Union of Concerned Scientists, 1992). In the same year, the

word

has National Academy of Sciences and the Royal Society of London (1992) issued ed.

hs, a joint statement recognizing the need for industrial countries to modify their

insert behavior radically to avoid irreversible damage to the earth's capacity to sustain

ally life. A 1993 Population Summit held in New Delhi explored issues of line lengt population growth, resource consumption, socioeconomic development, and original work e h

t environmental protection; 58 of the world's national academies of sciences (Science Summit, 1993) called for action to turn 1994 into "the year when the he original;

ion of people of the world decided to act together for the benefit of future t at o generations." The Ecological Society of America (Lubchenco et al., 1991) and ue t r have been accident the International Association of Ecology (Huntley et al., 1991) called for y t a research initiatives to move society toward sustainable use of ecological represent m are

l resources; so have Sigma Xi (1992) and the Carnegie Commission (1992a,b,c; a 1993). errors Universities and governments have also joined the chorus. In the 1990

age breaks Talloires Declaration (Cortese, 1993), the leaders of hundreds of universities P is new digit

h from throughout the world expressed their deep concern "about the pographic y iles. T t

f unprecedented scale and speed of environmental pollution and degradation, and e ile: ng i f the depletion of natural resources." The 1992 Earth Summit in Rio de Janeiro t F

D was an unprecedented gathering of representatives from 170 nations (the largest P peset and som

is meeting ever y h t

ined, a bout A ret original t

ion. om

r of world leaders) and grassroots organizations to explore international ibut f r t cannot dimensions of environmental issues and define steps necessary to run our r at not

o economies and secure our future (Center for Our Common Future, 1993). f Business and labor also recognize the need for change. Forty-eight

however, international industrialists and business leaders from more than 25 countries version ng,

t recently called for renewed efforts by business and government to make paper book, at ive ecological imperatives part of the market forces governing production, at rm o investment, and trade (Schmidheiny and Timberlake, 1992). In 1990 the Sunday riginal horit ic f

o Times of London reported (Fallon, 1990): "Sir James Goldsmith--corporate e h predator extraordinary, scourge of board rooms, one of the most feared men on t he aut t Wall Street--[is] retiring from business. From now on, he said, he would devote om r as ing-specif t his energies and much of his fortune of more than $1 billion to ecological and ion ed f environmental causes." Great wealth, the 57-year-old billionaire argued, was of peset y no value in a crumbling world. publicat

her t The United Steelworkers of America (1990) overwhelmingly endorsed a iles creat is h t

L f report that says, "We cannot protect steelworker jobs by ignoring environmental

M of

and ot problems." Further, the "greatest threat to our children's future may lie in the X destruction of their environment," and "the environment outside the workplace om yles, r f is only an extension Of the environment inside." At the August 1993 Parliament st version of World's Religions (Briggs, 1993), the leaders of Christianity, Buddhism, print posed

e Islam, Judaism, Hinduism, and other faiths developed a ''global ethic." Among h heading other things, that ethic condemns environmental abuses. In an age of recom

use t unparalleled technological progress, poverty, hunger, the death of children, ''and the destruction of nature have not diminished but rather have increased." breaks, ease l been

P A recent report by the Commission on Life Sciences of the National

word

has Research Council (1993) concludes that science and engineering provide many ed.

hs, "tools to address environmental problems of enormous consequence to our

insert social and economic well-being. But we are not using those tools most

ally effectively." line lengt original work e h t THE PROBLEM OF BIOTIC IMPOVERISHMENT he original;

ion of These organizations and the constituencies they represent recognize that all t at o is not well on planet Earth; planetary life-support systems critical to human ue t r have been accident society are threatened. The threat is loss of biological integrity, or biotic y t a impoverishment--the systematic reduction in the earth's ability to support living represent m are

l systems. Important aspects of biotic impoverishment include the following a (Karr, 1995a): errors

• Soil depletion, decertification, and salinization

age breaks • Depletion of renewable natural resources (e.g., forests and fisheries) P is new digit h

pographic • Depletion and contamination of water supplies y iles. T t

e • Extinction of species ile: ng i f t • Habitat destruction and fragmentation F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r • Alteration of global biogeochemical cycles ibut f r t cannot • Epidemics and pest outbreaks r at not

o • Introduction of exotic species f • Chemical contamination

however, • Global climate change; ozone depletion version ng,

t • Reduction in human cultural diversity paper book, at ive • Reduced quality of human life and economic deprivation at rm o • Environmental injustice and racism riginal horit ic f o

e Collectively, this broad sweep of issues illustrates the magnitude of the h t

he aut environmental challenge facing all members of the human community. It also t

r reminds us of the close association and common underpinning of environmental as ing-specif t and social concerns. The loss of species, the destruction of agricultural lands, ion ed f

peset and the differential exposure of economically disadvantaged people to y environmental hazards degrade the quality of human life. As human influence publicat her t

iles creat expands, the limits of technology, especially unintended consequences of is h t L f technology, become more obvious. Depletion of water supplies cannot be M of

and ot "fixed" by science's making water to refill aquifers. Citizens and political X

om leaders, engineers and ecologists must work together to develop creative yles, r f st version solutions; failure to do that will relegate the world to continued biotic impoverishment and threaten the sustainability of human society. print posed e h heading

recom ECOLOGICAL INTEGRITY AND ECOLOGICAL HEALTH use t

breaks, If biotic impoverishment is the problem, then protecting the integrity of ease l been P

biological systems must be the goal. But how do we define biological integrity word has

ed. in a world that is increasingly altered by the actions of humans? How do we hs, reconcile the inevitable changes required to accommodate a growing human insert population and the proliferation of modern technology while guarding the

ally planet from irrevocable biotic impoverishment? Answering these questions in line lengt

original work clear and explicit terms is especially important as we seek to bring scholars e h t

from diverse disciplines together to focus on common problems. What do health and integrity mean? What kind of health or integrity do we he original; ion of

t seek? Are we seeking "environmental health," or is that phrase too narrowly at o associated with human health? As a societal goal, biological integrity suggests a ue t r have been accident

y meaning beyond human health. The sum of physical, chemical, and biological t a integrity is ecological integrity (Karr and Dudley, 1981). Restoring and represent m are

a maintaining the "physical, chemical, and biological integrity of the nation's errors

waters" has been a goal of the Clean Water Act in the United States since 1972 and of the International Joint Commission (U.S. and Canada) on the Great

age breaks Lakes. "Maintenance of ecological integrity" is the first priority of the P is new digit h

pographic amendment to Canada's National Park Act passed by Parliament in 1988. y iles. T t

e Integrity implies an unimpaired condition or the quality or state of being ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r complete or undivided; it implies correspondence with some original condition. ibut f r t cannot Biological integrity (Angermeier and Karr, 1994; Frey, 1975; Karr and Dudley, r at not

o 1981; Karr et al., 1986) refers to the capacity to support and maintain a f balanced, integrated, adaptive biological system having the full range of

however, elements (genes, species, assemblages) and processes (mutation, demography, version ng,

t biotic interactions, nutrient and energy dynamics, and metapopulation paper book, at ive processes) expected in the natural habitat of a region. Although somewhat long- at rm o winded, this definition carries the message that (1) biology acts over a variety of riginal horit ic f

o scales from individuals to landscapes, (2) biology includes items one can count e h (the elements of biodiversity) plus the processes that generate and maintain t he aut t them, and (3) biology is embedded in dynamic evolutionary and biogeographic om r as ing-specif t contexts. ion ed f An evolutionary foundation ties the concept of integrity to a benchmark peset y against which society can evaluate sites altered by human actions. The complex publicat

her t biological systems that evolved at a site have already demonstrated their ability iles creat is h t

L f to persist in, even modify, the region's physical and chemical environment.

M of

and ot Their very presence means that they are resilient to the normal variation in that X environment. Species abundance, for example, changes as a function of changes om yles, r f in the physical environment and in interactions among species in a local st version assemblage. But the bounds over which systems change as a result of most print posed

e natural events are limited when compared with the changes imposed by human h heading activities such as row-crop agriculture, urbanization, or dam construction. recom

use t Human society sets aside extensive areas as parks and reserves to protect their natural state or integrity. Those areas deserve protection because of the breaks, ease l been

P diverse values they provide to society. Water bodies, including both surface and

word

has groundwaters, deserve special protection as well, because they provide water to ed.

hs, society and support recreational and other values. Further, they are the lifelines

insert of a continent, reflecting the condition of surrounding landscapes, linking

ally landscapes across great distances. line lengt Few places maintain a biota with evolutionary and biogeographic integrity original work e h

t because of the demands of feeding, clothing, and housing more than 5.7 billion people. The growth of human populations in the last few centuries has made the he original;

ion of human species the principal driver of change on Earth. Humans appropriate the t at o equivalent of 40 percent of Earth's annual terrestrial production (Vitousek et al., ue t r have been accident 1986). Providing for that human population requires massive alteration of the y t a planet in ways that preclude a return to the pristine environments of the pre- represent m are

l industrial era. Thus, biological integrity is lost on a large share of the planet and a is unlikely to be regained. Yet loss of ecological integrity for all lands and errors waters in all regions of the world is unacceptable on scientific, economic,

age breaks aesthetic, and ethical grounds. P is new digit

h Health, on the other hand, implies a flourishing condition, well-being, pographic y iles. T t

f vitality, or prosperity. An organism is healthy when it performs all its vital e ile: ng i f functions normally and properly; a healthy organism is resilient, able to recover t F

D from many stresses; a healthy organism requires minimal outside care. The P peset and som is concept of health y h t

ined, a bout A ret original t

ion. om

r applies to individual organisms as well as to national or regional economies, ibut f r t cannot industries, and natural resources such as fisheries. r at not

o Ecological health describes the goal for the condition at a site that is f cultivated for crops, managed for tree harvest, stocked for fish, urbanized, or

however, otherwise intensively used. At these sites, integrity in an evolutionary sense version ng,

t cannot be the goal. Healthy land use, with or without active management, paper book, at ive should not degrade the site for future use or degrade areas beyond the site. at rm o Soils, for example, should not be eroded or otherwise transformed to reduce riginal horit ic f

o future productivity (see Pimentel, 1993). Groundwater should not be depleted. e h Land use should not have deleterious effects beyond a site; atmospheric t he aut t

om contamination should not result in downwind effects, such as increased r as ing-specif t greenhouse gases or ozone depletion. Healthy sites should not release ion ed f contaminants or eroded soils that degrade sites elsewhere. Using these two peset y criteria--no degradation of the site for future use and no degradation of areas publicat

her t beyond the site--most modem agricultural and urban land use, for example, is iles creat is h

t not sustainable. Recognition of that reality is the foundation for recent L f

M of

and ot initiatives for sustainable communities and sustainable agriculture. X Failure to protect the ecological health of intensively used lands is also om yles, r f unacceptable on scientific, economic, aesthetic, and ethical grounds. We have st version no choice but to develop a conceptual framework to define acceptable and print posed

e sustainable uses. h heading These concepts are easily applied to small parcels of land. Scaling up to recom

use t large landscapes presents a serious challenge. What proportion of a landscape should be protected under a biological integrity goal? The World Commission breaks, ease l been

P on Environment and Development (1987) recommended 12 percent, but that

word

has seems inadequate. Does that proportion vary among regional ecosystem types ed.

hs, (e.g., desert, forest, or grassland)? Do water bodies, fragile sites, or sites with

insert the highest biodiversity deserve the highest priority for protection? ally line lengt original work

e MEASURING HEALTH AND INTEGRITY h t Neither ecologists nor engineers have been especially adept at defining or he original;

ion of measuring either ecological health or ecological integrity. The track record of t at o freshwater management provides an instructive example. Human society ue t r have been accident depends on freshwater as well as the resources associated with freshwater and y t a marine systems. Yet 55 countries now have populations that equal or exceed the represent m are

l ability of their national territory to provide an adequate supply of freshwater a (Ozturk, 1995). Improved water conservation, treatment and recycling programs errors can delay the crisis, but growing human populations will keep society on a

age breaks treadmill trying to keep up with expanding demand. Even where the supply of P is new digit

h water remains adequate, resource degradation continues because society pographic y iles. T t

chronically undervalues the products and services provided by aquatic f e ile: ng i f ecosystems. t F

D Although rivers are in many ways the lifeblood of society, prevalent P peset and som is attitudes y h t

ined, a bout A ret original t

ion. om

r toward rivers reflect disdain for their value and arrogance about our ability to ibut f r t cannot replace or repair them. Despite the mandate in the Clean Water Act for r at not

o protecting the integrity of the nation's waters, for example, it took nearly two f decades to begin to incorporate that concept into water resource protection,

however, largely because appropriate benchmarks were not defined for evaluating success version ng,

t in attaining those goals. That failure leads to six "realities" about the condition paper book, at ive of water resources (Karr, 1995b). at rm o

riginal 1. Water resources, especially their biological components, are in steep horit ic f o

e decline. The proportion of aquatic organisms at risk of extinction is h t

he aut considerably higher than that of terrestrial organisms (Angermeier and t

r Karr, 1994; Masters, 1990). The spread of exotics and the decline of as ing-specif t native species are common to waters throughout the United States. Fish ion ed f

peset consumption advisories are issued each year in more than 40 states, and y riparian corridors along U.S. streams have been destroyed in most areas. publicat her t

iles creat Despite strong mandates and massive expenditures to protect "the is h t L f physical, chemical, and biological integrity" of the nation's waters, signs M of

and ot of continuing degradation are pervasive within individual rivers, the X

om continent, and the globe. yles, r f st version 2. Degradation stems from more than chemical contamination, the primary focus of conventional water-quality programs. The print posed e assumption that monitoring for chemical contaminants ensures chemical, h heading physical, and biological integrity is flawed. Society wastes money and recom

use t degrades resources because decisions based on chemical criteria do not

breaks, adequately protect water quality. Priority lists of chemicals do not ease l been P

accurately reflect ecological risks; point-source approaches do not word has

ed. effectively control the influence of nonpoint sources or the cumulative hs, effects of numerous contaminants; and the chemical-contaminant insert approach fails to diagnose and correct water resource problems caused by

ally other human influences, such as degradation of physical habitat or line lengt

original work alteration in flow (Karr, 1991). e h t

3. Long-term success in protecting water resources requires careful thought about goals, or benchmarks, Including development and uses he original; ion of

t of criteria for protecting ecological Integrity. Water resources are not at o simply water; their quality and value to society depend on more than ue t r have been accident

y water quality and quantity alone. We must begin to track the condition of t a our waters as we track the status of local and national economies. represent m are

a Biological monitoring and biological criteria provide the most robust errors

approach. Waterways that cannot support healthy biological communities are unlikely to support human society for long.

age breaks 4. The legal and regulatory framework in place today does not respond P is new digit h

pographic soon enough to continued degradation. Government agencies have been y iles. T t

e weak, inappropriately focused, and therefore largely ineffective at ile: ng i f t reversing resource declines, especially those not associated with point F

D sources of chemical contamination. This observation is Consistent with P peset and som is y the observation that major environmental legislation derives from the h t effectiveness of grassroots organizations, not ined, a bout A ret original t

ion. om

r from the leadership of government agencies. The effectiveness of that ibut f r t cannot legislation is diminished because regulations to enforce it often r at not

o compromise legislative goals (Greider, 1992; Karr, 1990). f Underfunding--the chronic complaint from all bureaucracies and

however, scientists--is not, however, the most important problem. Failure to set a version ng,

t clear societal goal and develop a comprehensive assessment and planning paper book, at ive effort to accomplish that goal is unacceptable. Too often, as in the at rm o implementation of the Clean Water Act, a least-cost option to reduce water riginal horit ic f

o discharge is selected on the basis of available technology, a political need e h for equity, and narrow medium-specific goals. Environmental protection t he aut t should emphasize the need to minimize insults to the total environment-- om r as ing-specif t land, water, and atmosphere. We can no longer afford to implement the ion ed f Clean Water Act as if crystal-clear, distilled water running down concrete peset y conduits were the objective. publicat

her t 5. The quantitative expectations that constitute biological integrity vary iles creat is h t

L f geographically. Criteria developed for chemical contaminants have been

M of

and ot applied uniformly for diverse water bodies. But the idea that the same X chemical criteria should apply to all waters is ludicrous, for the om yles, r f underlying physical and chemical properties of streams vary regionally. st version Evolutionary and biogeographic variation are key components of print posed

e biological integrity. h heading 6. Because biological systems are complex, multiple components of recom

use t biology should be protected. Measurement of all components is logistically impossible. Thus, we must define a reasonable set of breaks, ease l been

P biological attributes that reliably track biological condition. Extensive

word

has experience in aquatic and terrestrial systems suggests that four key ed.

hs, biological features should be tracked: species richness, species

insert composition, individual health, and trophic (food web) structure.

ally Collectively, these attributes detect (1) changes in species, including the line lengt identity and number of species present in the regional biota (elements); original work e h

t (2) ecological processes such as nutrient dynamics and energy flow through food webs; and (3) health of individuals, which is likely to he original;

ion of influence demographic processes. t at o Several approaches have been developed in the past decade to integrate ue t r have been accident

y complex biological data. The development of a multimetric approach (multiple t a biological attributes are evaluated to assess resource condition) for use in represent m are

a freshwater streams in the United States (Fausch et al., 1984; Karr, 1981, 1991; errors

Karr et al., 1986) stimulated researchers and agency staff to adopt a similar method in water resource evaluations over a wider geographic area (Crumby et

age breaks al., 1990; Deegan et al., 1993; Fausch and Schrader, 1987; Hughes and P is new digit h

pographic Gammon, 1987; Leonard and Orth, 1986; Lyons, 1992; Oberdorff and Hughes, y iles. T t

e 1992; Steedman, 1988) and with a variety of taxa (Kerans and Karr, 1994; Ohio ile: ng i f t EPA, 1988; Plafkin et al., 1989). F

D The multimetric approach works because it recognizes biology as P peset and som is y fundamentally important, selects only biologically meaningful and reliable h t measures, and is easy to communicate to policymakers and citizens. The ined, a

bout multimetric approach A ret original t

ion. om

r provides a structure for knowledge that uses the common sense of biologists ibut f r t cannot familiar with a regional biota, much as economic indices use common sense r at not

o about economic conditions (e.g., Dow-Jones Average, Index of Leading f Economic Indicators). Properly conceived and used, multimetric approaches

however, based in sound biology are statistically rigorous (Fore et al., 1994). They version ng,

t provide a way to summarize complex information in a single quantitative paper book, at ive expression while preserving information about each biological attribute. at rm o Properly selected measures of biological integrity can be used to determine riginal horit ic f

o whether life-support systems are degraded and identify the factors responsible e h for degradation. They may even be used to track the success of restoration t he aut t programs. om r as ing-specif t ion ed f peset

y DEVELOPING INTEGRATED SOLUTIONS publicat

her t If we are to stem biotic impoverishment and reverse environmental iles creat is h t

L f degradation, we must

M of

and ot • Set societal goals based on broad concepts of ecological integrity and X

om ecological health. yles, r f st version • Forge partnerships among scientists, engineers, policymakers, resource managers, and citizens to develop approaches for attaining those goals. print posed e • Revise the legal framework guiding environmental policy to ensure that h heading both ecological risks and threats to human health are minimized. recom

use t • Protect existing resources.

breaks, • Restore resources that are degraded. ease l been P

word has ed.

hs, BRINGING ENGINEERS AND ECOLOGISTS TOGETHER

insert Two disciplines of fundamental importance to human society, engineering

ally and ecology, have expanded at unprecedented rates during the twentieth line lengt

original work century. Most practitioners of one of these disciplines have only limited e h t

knowledge about the other, and fundamental conceptual differences have limited their interaction. Engineering developed to improve the lot of humans; he original; ion of

t most engineering incorporates only the chemical and physical dimensions of the at o natural world. The failure of engineering to recognize the importance of ue t r have been accident

y biological limits and connectivity within biological systems is matched by the t a failure of ecology to contribute to the resolution of important societal problems. represent m are

a Engineers and ecologists fail to address the right problem at the right time. errors

Engineers are accustomed to others defining problems for them to solve, or they propose inappropriate solutions to perceived problems. Ecologists spend too

age breaks much time trying to understand problems before they take action. They may be P is new digit h

pographic incapable of contributing useful solutions because they get lost in the details of y iles. T t

e natural environmental variation. ile: ng i f t Today societal realities compel both disciplines to improve their craft by F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r expanding their interactions in the service of society. Those interactions must be ibut f r t cannot based on mutual respect and understanding and on actions to avert the r at not

o consequences of continued biotic impoverishment. f Traditionally, human actions have not been evaluated so that their

however, influence on ecological health or integrity was identified. When human version ng,

t populations were small, resources were abundant, technological skills were less paper book, at ive advanced, and environmental degradation was less extreme. As a result, society at rm o did not notice or understand ecological integrity or health because degradation riginal horit ic f

o was local and usually transitory. An undeveloped frontier was always available. e h But the frontier is gone; supplies of many renewable resources have been t he aut t depleted; chemical pollution is pervasive; and the global atmosphere is om r as ing-specif t changing under the onslaught of human actions. ion ed f We cannot avoid the use of technology, but we can no longer adopt peset y technology without careful evaluation of its ecological effects. Most technology publicat

her t has been directed toward important, but narrow and typically short-term goals, iles creat is h t

L f such as protecting human health, achieving economic "efficiency," or replacing

M of

and ot lost natural resources. Rarely have careful evaluations of the long-term X consequences of a technology been completed before the technology was om yles, r f adopted. We must change our approach. We must ensure that protection of st version ecological health and integrity plays a central role in decisions about consumer print posed

e goods and development of technologies, including when, where, and how to h heading apply technology. Failure to protect ecological integrity and ecological health recom

use t across all landscapes is probably the most serious threat to the security of individuals, nations, and global human society. breaks, ease l been P

word has ed. ACKNOWLEDGMENTS hs,

insert Thanks to Ellen W. Chu, Leska Fore, Brian Mar, and Gene Welch for

ally commenting on earlier drafts of this manuscript. line lengt original work e h t REFERENCES

he original; Allenby, B. R., and D. J. Richards, eds. 1994. The Greening of Industrial Ecosystems. Washington, ion of t at o D.C.: National Academy Press. Angermeier, P. L., and J. R. Karr. 1994. Biological integrity versus biological diversity as policy ue t r have been accident directives: Protecting biotic resources. BioScience 44:690-697. y t

a Briggs, D. 1993. World's clerics draft global ethic: Violence, sexism, environmental abuse are all represent m

are targeted. The Seattle Times, Seattle, Wash. September 1, 1993.

a Bullard, R. D., ed. 1994. Unequal Protection: Environmental Justice and Communities of Color. San Francisco, Calif.: Sierra Club Books. errors Carnegie Commission. 1992a. Environmental Research and Development: Strengthening the Fed- era Infrastructure. New York: Carnegie Commission on Science, Technology, and age breaks Government. P is new digit

h Carnegie Commission. 1992b. International Environmental Research and Assessment: Proposals for pographic y iles. T t Better Organization and Decision Making. New York: Carnegie Commission on Science,

f e

ile: Technology, and Government. ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Carnegie Commission. 1992c. Partnerships for Global Development: Clearing the Horizon. New r ibut f r York: Carnegie Commission on Science, Technology, and Government. t cannot Carnegie Commission. 1993. Science, Technology, and Government for a Changing World. New r at not

o York: Carnegie Commission on Science, Technology, and Government. f Center for Our Common Future. 1993. The Earth Summit's Agenda for Change: A Plain Language Version of Agenda 21 and the Other Rio Agreements. Geneva, Switzerland: Center for however, Our Common Future. version ng,

t Colborn, T., and C. Clement, eds. 1992. Chemically-induced alterations in sexual and functional paper book, at ive development: The wildlife/human connection. Advances in Modern Environmental at rm Toxicology 21:1-403. o

riginal Cortese, A. D. 1993. Building the intellectual capacity for a sustainable future: Talloires and horit ic f

o beyond. Pp. 1-9 in Environmental Literacy and Beyond, B. Wallace, J. Cairns, Jr., and P. e

h A. Distler, eds. Presidents Symposium Vol. V. Blacksburg, Va.: Virginia Polytechnic t he aut t

Institute and State University. om r

as Costanza, R., ed. 1991. Ecological Economics: The Science and Management of Sustainability. ing-specif t New York: Columbia University Press. ion ed f Costanza, R., B. G. Norton, and B. D. Haskell, eds. 1992. Ecosystem Health: New Goals for peset

y Environmental Management. Washington, D.C.: Island Press. Crumby, W. D., M. A. Webb, and F. J. Bulow. 1990. Changes in biotic integrity of a modified river publicat

her t in north central Tennessee . Transactions of the American Fisheries Society 119:885-893. iles creat is

h Deegan, L. A., J. T. Finn, S. G. Ayvazian, and C. Ryder. 1993. Feasibility and application of the t L f index of biotic integrity to Massachusetts estuaries (EBI). Final Project Report. Woods M of

and ot

X Hole, Mass.: Ecosystems Center, Marine Biological Laboratory. Dunlap, R. E., G. H. Gallup, Jr., and A. M. Gallup. 1993. Of global concern: Results of the Health om yles, r f of the Planet Survey. Environment 35(9):7-15, 33-39. st version Fallon, I. 1990. The jolly green giant. The Sunday Times (London). October 21, 1990, p. 15. Fausch, K. D., and L. H. Schrader. 1987. Use of the index of biotic integrity to evaluate the effects print posed

e of habitat, flow, and water quality on fish communities in three Colorado Front Range h

heading streams. Final Report. Fort Collins, Colo.: Department of Fishery and Wildlife Biology,

recom Colorado State University.

use t Fausch, K. D., J. R. Karr, and P. R. Yant. 1984. Regional application of an index of biotic integrity

breaks, based on stream fish communities. Transactions of the American Fisheries Society ease l been 113:39-55. P Fore, L. S., J. R. Karr, and L. L. Conquest. 1994. Statistical properties of an index of biological word has ed. integrity used to evaluate water resources. Canadian Journal of Fisheries and Aquatic hs, Science 51:1077-1087.

insert Frey, D. 1975. Biological integrity of water: An historical perspective. Pp. 127-139 in The Integrity of Water, R. K. Ballentine and L. J. Guarraia, eds. Washington, D.C.: Environmental ally Protection Agency. line lengt

original work Greider, W. 1992. Who Will Tell the People? The Breakdown of American Democracy. New York: e

h Simon and Schuster. t Hughes, R. M., and J. R. Gammon. 1987. Longitudinal changes in fish assemblages and water quality in the Willamette River, Oregon. Transactions of the American Fisheries Society he original;

ion of 116:196-209. t at o Huntley, B. J., and 18 other authors. 1991. A sustainable biosphere: The global imperative. Ecology International 1991:20. ue t r have been accident y

t Jansson, A., M. Hammer, C. Folke, and R. Costanza, eds. 1994. Investing in Natural Capital: The a Ecological Economics Approach to Sustainability. Washington, D.C.: Island Press. represent m are

l Karr, J. R. 1981. Assessment of biotic integrity using fish communities. Fisheries 6(6):21-27. a Karr, J. R. 1990. Biological integrity and the goal of environmental legislation: Lessons for errors

conservation biology. Conservation Biology 4:244-250. Karr, J. R. 1991. Biological integrity: A long neglected aspect of water resource management.

age breaks Ecological Applications 1:66-84. P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Karr, J. R. 1993. Protecting ecological integrity: An urgent societal goal. Yale Journal of r ibut f r International Law 18:297-306. t cannot Karr, J. R. 1995a. Using biological criteria to protect ecological health. Chapter 8 in Evaluating and r at not

o Monitoring Health of Large-scale Ecosystems, D. J. Rapport, C. Gaudet, and P. Calow, f eds. New York: Springer-Verlag. Karr, J. R. 1995b. Protecting the integrity of aquatic ecosystems: Clean water is not enough. In however, Biological Assessment and Criteria: Tools for Water Resource Planning and Decision version ng,

t Making, W. S. Davis and T. P. Simon, eds. Boca Raton, Fla.: Lewis Publishers. paper book, at ive Karr, J. R., and D. R. Dudley. 1981. Ecological perspective on water quality goals. Environmental at rm Management 5:55-68. o

riginal Karr, J. R., K. D. Fausch, P. L. Angermeier, P. R. Yant, and I. J. Schlosser. 1986. Assessing horit ic f

o Biological Integrity in Running Waters: A Method and its Rationale. Special Publication e

h No. 5. Champaign, Ill.: Natural History Survey. t he aut t

Kerans, B. L., and J. R. Karr. 1994. A benthic index of biotic integrity (B-IBI) for rivers of the om r

as Tennessee Valley. Ecological Applications 3:768-785. ing-specif t Leonard, P. M., and D. J. Orth. 1986. Application and testing of an index of biotic integrity in small, ion ed f coolwater streams. Transactions of the American Fisheries Society 115:401-414. peset

y Lubchenco, J., and 15 coauthors. 1991. The sustainable biosphere initiative: An ecological research agenda. Ecology 72:371-412. publicat

her t Lyons, J. 1992. Using the Index of Biotic Integrity (IBI) to Measure Environmental Quality in iles creat is

h Warmwater Streams of Wisconsin. General Technical Report NC-149. St. Paul, Minn.: t L f Forest Service, U.S. Department of Agriculture. M of

and ot

X Masters, L. 1990. The imperiled status of North American aquatic animals. Biodiversity Network News (Nature Conservancy) 3(3):1-2, 7-8. om yles, r f Meffe, G. K., and C. R. Carroll. 1994. Principles of Conservation Biology. Sunderland, Mass.: st version Sinaeur Associates. National Academy of Sciences (U.S.), and Royal Society of London. 1992. Population Growth, print posed

e Resource Consumption, and a Sustainable World. Joint Statement by the Officers of the h

heading Royal Society of London and the U.S. National Academy of Sciences, Washington, D.C.

recom National Research Council. 1993. Research to Protect, Restore, and Manage the Environment.

use t Washington, D.C.: National Academy Press.

breaks, Oberdorff, T., and R. M. Hughes. 1992. Modification of an index of biotic integrity based on fish ease l been assemblages to characterize rivers of the Seine Basin, France. Hydrobiologia 228:117-130. P Ohio Environmental Protection Agency. 1988. Users Manual for Biological Field Assessment of word has ed. Ohio Surface Waters. 3 volumes. Columbus, Ohio: Surface Water Section, Division of hs, Water Quality Monitoring and Assessment, Ohio Environmental Protection Agency.

insert Ozturk, M. A. 1995. Recovery and rehabilitation of Mediterranean type ecosystem: A case study from Turkish Maquis. Chapter 17 in Evaluating and Monitoring the Health of Large-scale ally Ecosystems, D. J. Rapport, C. Gaudet, and P. Calow, eds. New York: Springer-Verlag. line lengt

original work Pimentel, D., ed. 1993. World Soil Erosion and Conservation. Cambridge Studies in Applied e

h Ecology and Resource Management. New York: Cambridge University Press. t Plafkin, J. L., M. T. Barbour, K. D. Porter, S. K. Gross, and R. M. Hughes. 1989. Rapid Bio- assessment Protocols for Use in Streams and Rivers: Benthic Macroinvertebrates and Fish. he original;

ion of EPA/440/4-89-001. Washington, D.C.: Environmental Protection Agency. t at o Rapport, D. J., C. Gaudet, and P. Calow, eds. 1994. Evaluating and Monitoring the Health of Large- scale Ecosystems. New York: Springer-Verlag. ue t r have been accident y

t Richards, D. J., and A. B. Fullerton, eds. 1994. Industrial Ecology: U.S.-Japan Perspectives. a Washington, D.C.: National Academy Press. represent m are

l Schmidheiny, S., and L. Timberlake. 1992. Changing Course: A Global Business Perspective on a Development and the Environment. Cambridge, Mass.: The MIT Press. errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Science Summit. 1993. Population Summit of the World's Scientific Academics. A Joint Statement r ibut f r by Fifty-eight of the World's Scientific Academies. Washington, D.C.: Office of t cannot International Affairs, National Research Council. r at not

o Sigma Xi. 1992. Global Change and the Human Prospect: Issues in Population, Science, f Technology and Equity. Forum Proceedings, November 16-18, 1991. Research Triangle Park, N.C.: Sigma Xi. however, Steedman, R. J. 1988. Modification and assessment of an index of biotic integrity to quantify stream version ng,

t quality in Southern Ontario. Canadian Journal of Fisheries and Aquatic Science 45:492-501. paper book, at ive Union of Concerned Scientists. 1992. World Scientists' Warning to Humanity. Cambridge, Mass.: at rm Union of Concerned Scientists. o

riginal United Steelworkers of America. 1990. Our Children's World: Steelworkers and the Environment. horit ic f

o Report of USWA Task Force on Environment. Washington, D.C.: United Steelworkers of e

h America. t he aut

t Vitousek, P. M., P. R. Ehrlich, A. H. Ehrlich, and P. Matson. 1986. Human appropriation of the

om r

as products of photosynthesis. BioScience 36:368-373. ing-specif t Westra, L. 1994. An Environmental Proposal for Ethics: The Principle of Integrity. Lanham, Md.: ion ed f Rowman and Littlefield Publishers. peset

y Wilson, E. O. 1992. The Diversity of Life. Cambridge, Mass.: Harvard University Press. World Commission on Environment and Development. 1987. Our Common Future. Oxford: Oxford publicat

her t University Press. iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ECOLOGICAL ENGINEERING: A NEW PARADIGM FOR ENGINEERS AND 111 ECOLOGISTS e h t be

ion. om r ibut f r t cannot r at not Ecological Engineering: A New Paradigm o f for Engineers and Ecologists however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h William J. Mitsch t he aut t

om r as ing-specif t A NEW COLLABORATION ion ed f peset

y The engineering profession is now in the position to make a substantial

publicat contribution to the ''greening'' of the planet through ideas such as ecological her t iles creat is

h engineering. In this retrospective period of human history, it is important to t L f

M of determine, without necessarily questioning all that has been built and

and ot X engineered to date, (1) whether to continue practices as usual (and whether we om yles, r

f can afford to do so), and (2) what new approaches are available to engineers for st version restoring the "bodily functions" of nature on which we depend. Many signs

print indicate that a shift is taking place both within and outside the engineering posed e h

heading profession to accommodate ecological approaches to what was formerly done

recom through rigid engineering and a general avoidance of any reliance on natural use t systems. For example, engineers, resource managers, and ecologists are breaks, ease l been rethinking whether to restore the upper Mississippi River levees to their state P before the 1993 floods or to take a more ecologically friendly approach. The word has ed.

hs, U.S. Army Corps of Engineers is now "greening" and some in that organization see themselves as the nation's ecological engineers. Agricultural engineers, insert known for the efficiency with which they drained the landscape, are retooling in ally

line lengt many locations to rebuild wetlands. The Kissimmee River in Florida is being original work

e "restored"--at enormous cost--to something resembling its former self before it h t was straightened 20 years ago. This paper presents the most recent definition of ecological engineering, he original; ion of t at o examines the new field in its historical context, contrasts it with other fields,

ue t presents a classification system for ecological engineering projects, and r have been accident y t

a summarizes recent events related to the development of the field. represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r DEVELOPMENT AND DEFINITION OF ECOLOGICAL ibut f r t cannot ENGINEERING r at not o f Ecological Engineering as an Extension of Ecology however, version ng,

t Ecological engineering is a new field with its roots in the science of paper book, at ive ecology. It can be viewed as designing or restoring ecosystems according to at rm o ecological principles learned over the past century (Figure 1). Ecology, as a riginal horit ic f

o field often designated as a discipline within the biological sciences, has had a e h strong history of development over the past century, dating back to the coining t he aut t

om of the term ecology by the German biologist Ernst Haeckel (1866). The r as ing-specif t principles of the field have been developed by scientists such as Cowles, ion ed f Shelford, Clements, Gleason, Lotka, Elton, Thienemann, Forel, Lindeman, peset y Likens, Hutchinson, the Odum brothers, and others. As with any science, much publicat

her t discussion centers on which theories are correct, particularly with ecological iles creat is h

t energetics and concepts such as succession, but a strong science has developed L f

M of

and ot at the population, community, and ecosystem levels. X Applied ecology, as an extension of these ecological theories, has become om yles, r f popular since the 1960s, particularly in light of public concern for st version environmental matters. But it has usually been limited to monitoring and print posed

e assessing environmental impacts or managing natural resources; that is, it has h heading principally remained descriptive. Good examples of recent applied fields in recom

use t ecology are ecotoxicology and landscape ecology, both of which are descriptive of humanity's effects on the environment. But description alone is not sufficient breaks, ease l been

P to deal with many of today's environmental issues. The solution to some of

word

has these seemingly unsolvable problems requires a prescriptive discipline (Odum, ed.

hs, 1989a), that is, one that depends on the environmental problems being defined

insert and then prescribes a solution to those problems. One recently proposed

ally prescriptive discipline is called ecological engineering (Mitsch and Jørgensen, line lengt 1989a; Mitsch, 1993). original work e h

t Both basic and applied ecology provide fundamental concepts to ecological engineering but do not define it completely. Ecological engineering he original;

ion of should have its roots in the science of ecology, just as chemical engineering is t at o close to chemistry and biochemical engineering is close to biochemistry. It ue t r have been accident logically should be considered a branch of ecology as well as a new field of y t a engineering. represent m are

l a errors Definition and Goals

age breaks At a May 1993 workshop on ecological engineering sponsored by the P is new digit

h National Research Council (see New Discipline, 1993), in a slight variation of pographic y iles. T t

f the definition given in the Mitsch and Jørgensen (1989b), ecological e ile: ng i f engineering was defined as t F D

P the design of sustainable ecosystems that integrate human society with its peset and som is y h

t natural environment for the benefit of both.

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version FIGURE 1 The relationships among ecology, applied ecology, and ecological print posed

e engineering. Ecological engineering depends on the theories developed by h heading traditional ecology (theoretical and applied), but knowledge gained from recom

use t successes and failures of ecological engineering systems will feed back to substantiate or refute many ecological theories (from Mitsch, 1993, copyright breaks, ease l been 1993 American Chemical Society, adapted with permission). P

word has ed.

hs, In short, it involves the building of ecosystems that have value to both

insert humans and nature. Ecological engineering combines basic and applied science for the restoration, design, and construction of aquatic and terrestrial ally

line lengt ecosystems. The goals of ecological engineering and ecotechnology are as original work e

h follows: t

1. The restoration of ecosystems that have been substantially disturbed by he original;

ion of human activities such as environmental pollution or land disturbance. t at o 2. The development of new sustainable ecosystems that have human and ue t r have been accident ecological value. y t a represent m are

l a History of Ecological Engineering errors

The term ecological engineering was coined by H. T. Odum in the 1960s

age breaks (Odum, 1962, 1971; Odum et al., 1963) and has since been used extensively in P is new digit

h North America, Europe, and especially China. Ecological engineering was first pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r defined in terms of energy flow as "those cases in which the energy supplied by ibut f r t cannot man is small relative to the natural sources, but sufficient to produce large r at not

o effects in the resulting patterns and processes" (Odum, 1962) and as f "environmental manipulation by man using small amounts of supplementary

however, energy to control systems in which the main energy drives are still coming from version ng,

t natural sources" (Odum et al., 1963). Odum (1971) elaborated on the breadth of paper book, at ive ecological engineering by stating that ''the management of nature is ecological at rm o engineering, an endeavor with singular aspects supplementary to those of riginal horit ic f

o traditional engineering." In his view, ''partnership with nature is a better term." e h Ecotechnology, which is sometimes used synonymously with ecological t he aut t engineering, has been described as "the use of technological means for om r as ing-specif t ecosystem management, based on deep ecological understanding, to minimize ion ed f the costs of measures and their harm to the environment" (Straskraba, 1993; peset y Straskraba and Gnauck, 1985). Combining ecosystem function with human publicat

her t needs is the emphasis of ecological engineering, defined by Mitsch and iles creat is h

t Jørgensen (1989b) as "the design of human society with its natural environment L f

M of

and ot for the benefit of both." That definition amplifies Odum's points by illustrating X that if society used the energy flows of nature as opposed to the fossil fuel- om yles, r f based energy of conventional technology, two issues could be addressed: (1) an st version environmental problem might be solved, and (2) precious nonrenewable print posed

e resources would not be expended in great amounts to accomplish this solution. h heading Ecological engineering provides approaches for conserving our natural recom

use t environment while at the same time adapting to and sometimes solving difficult environmental pollution problems. breaks, ease l been

P The term ecological engineering has been applied to the treatment of

word

has wastewater and septage in ecologically based "green machines," with indoor ed.

hs, greenhouse applications built both in Sweden and the United States in the late

insert 1980s (Guterstam and Todd, 1990; Teal and Peterson, 1991, 1993). Here the

ally applications are described as "environmentally responsible technology [which] line lengt would provide little or no sludge, generate useful by-products, use no hazardous original work e h

t chemicals in the process chain, and remove synthetic chemicals from the wastewater" (Guterstam and Todd, 1990). All applications within this subset of he original;

ion of ecological engineering use ecosystems for treatment of human wastes, with an t at o emphasis on truly solving problems with an ecological system rather than ue t r have been accident simply shifting the problem to another medium. y t a Concurrent with, but separate from, development of ecological engineering represent m are

l concepts in the West was the emergence of a similar development of the term a ecological engineering in China (see Mitsch et al., 1993a, for an entire issue of errors a journal dedicated to ecological engineering in China). Much of the approach

age breaks to environmental management in China has remained an art, but in the past P is new digit

h decade there has been explicit use of the term ecological engineering in China pographic y iles. T t

f to describe a formal "design with nature" philosophy of the late Professor Ma e ile: ng i f Shijun (Ma, 1985, 1988; Ma et al., 1988; Ma and Yan, 1989). Ma (1988) t F

D defined ecological engineering as "a specially designed system of production P peset and som

is processes y h t

ined, a bout A ret original t

ion. om

r in which the principles of the species symbiosis and the cycling and ibut f r t cannot regeneration of substances in an ecological system are applied while adopting r at not

o the systems engineering technology and introducing new technologies and f excellent traditional production measures to make a multi-step use of

however, substance." He suggested that ecological engineering was first proposed in version ng,

t China in 1978 and is now used throughout the country, with about 500 sites that paper book, at ive practice agro-ecological engineering, defined as an "application of ecological at rm o engineering in agriculture" (Ma, 1988). That number has since been updated to riginal horit ic f

o about 2,000 applications of ecological engineering in China (Yan and Zhang, e h 1992; Yan et al., 1993). At a Symposium on Agro-ecological Engineering in t he aut t Beijing (Ma et al., 1988), Qi and Tian (1988) suggested that "the objective of om r as ing-specif t ecological research [in China] is being transformed from systems analysis to ion ed f system design and construction," stating that ecology now has a great peset y knowledge base from observational and experimental ecology and is in the publicat

her t position to meet global environmental problems through ecosystem design, the iles creat is h

t main task of ecological engineering. Yan and Yao (1989) describe integrated L f

M of

and ot fish culture management as it is practiced in China as ecological engineering X because of its attention to waste recycling and use om yles, r f st version PRINCIPLES IN ECOLOGICAL ENGINEERING print posed e h heading A few basic concepts collectively distinguish ecological engineering from recom

use t more conventional engineering approaches to solving environmental problems:

breaks, 1. Application of self-design. ease l been P

2. Ecosystem building as the acid test of ecological theories. word has

ed. 3. Reliance on system approaches. hs, 4. Conservation of nonrenewable energy sources. insert 5. Conservation of nature. ally line lengt original work e

h Self-design t

Ecotechnology is dependent on the self-designing capability of ecosystems he original; ion of

t and nature. When changes occur, natural systems shift, species are substituted at o for each other, and food chains reorganize. As individual species sort, as some ue t r have been accident

y arc selected and others are not, a new system ultimately emerges that is well t a suited to the environment superimposed on it. Humans participate in self-design represent m are

a by providing choices of initial species, matching species with the environment. errors

Nature does the rest. For example, in designing a wetland, we may want to introduce dozens of different plants at different water depths because of our

age breaks inability to predict exactly where certain plants will survive and even if they P is new digit h

pographic will survive at all. Nature then takes over and chooses the plants that will thrive y iles. T t

e at certain water depths, soil conditions, and grazing pressures. Odum (1989a) ile: ng i f t refers F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r to this capability of self-design as self-organization, which "designs a mix of ibut f r t cannot man-made and ecological components [in a] pattern that maximizes r at not

o performance, because it reinforces the strongest of alternative pathways that are f provided by the variety of species and human initiatives." Multiple seeding of

however, species into ecologically engineered systems is one way to speed the selection version ng,

t process in this self-organization, or self-design (Odum, 1989b). As described by paper book, at ive Mitsch and Jørgensen (1989b): at rm o riginal horit ic f [Ecological engineering] is engineering in the sense that it involves the design o

e of this natural environment using quantitative approaches and basing our h t he aut

t approaches on basic science. It is technology with the primary tool being self-

om r as ing-specif designing ecosystems. The components are all of the biological species of the t

ion world. ed f peset y This focus on, and use of, biological species, communities, and ecosystems publicat her t with a reliance on self-design is one feature that distinguishes ecotechnology iles creat is h t L f from the traditional engineering technologies, which rely on devices and M of

and ot facilities to remove, transform, or contain pollutants, but which do not consider X direct manipulation of ecosystems. om yles, r f st version

print The Acid Test posed e h heading The ecological theories that have been put forward in scholarly ecological recom

use t publications over the past 100 years need to serve as the basis of the language

breaks, and the practice of ecological engineering. But just as there is the possibility of ease l been

P these theories providing the basis for engineering design of ecosystems, there is

word

has a high probability of advancing the understanding of ecological systems in ed. hs, ecological engineering because of the unique research approach that

insert reconstructing ecosystems provides to scientists. Bradshaw (1987) has

ally described the restoration of a disturbed ecosystem as the "acid test of our line lengt

original work understanding of that system." Restoration ecologists have made a clear e h

t connection between basic research and ecosystem restoration through the

analogy that the best way to understand a system, whether a car or a watch, is to he original;

ion of "attempt to reassemble it, to repair it, and to adjust it so that it works properly" t at o (Jordan et al., 1987). Thus, ecotechnology is really a technique for doing ue t r have been accident fundamental ecological research and applying it. y t a represent m are

l a A Synthesis, not Reductionism errors

Ecological engineering emphasizes, as does systems modeling for

age breaks ecologists, the need to consider the entire ecosystem, compartment by P is new digit

h compartment, but ultimately to make a whole. Odum (1989a) has stated that the pographic y iles. T t

f practice of ecological engineering cannot be supported completely by reductive, e ile: ng i f

t analytic, experimental testing and relating. Approaches such as modeling and F

D benefit-cost analysis are more important, as ecosystem design and prognosis P peset and som is y cannot be predicted h t

ined, a bout A ret original t

ion. om

r by summing parts to make a whole. We must learn to work with whole ibut f r t cannot ecosystems rather than one species at a time. We must be able to synthesize a r at not

o great number of disciplines to understand and deal with the design of f ecosystems. Restoration ecology, a subfield of ecological engineering, has been

however, described as a field in which the investigator is forced to study the entire system version ng,

t rather than components of the system in isolation from each other (Cairns, paper book, at ive 1988b). Cairns goes on to state that "One of the most compelling reasons for the at rm o failure of theoretical ecologists to spend more time on restoration ecology is the riginal horit ic f

o exposure of serious weaknesses in many of the widely accepted theories and e h concepts of ecology" (Cairns, 1988b). t he aut t

om r as ing-specif t ion

ed f Nonrenewable Resource Conservation peset y Because most ecosystems are primarily solar-based systems, they are self- publicat

her t sustaining. Once an ecosystem is constructed, it should be able to sustain itself iles creat is h t

L f indefinitely through self-design with only a modest amount of intervention.

M of

and ot This means that the ecosystem, running on solar energy or the products of solar X energy, should not need to depend on technological fossil energies as much as it om yles, r f would if a traditional technological solution to the same problem were st version implemented. If the system does not sustain itself, it does not mean that the print posed

e ecosystem has failed us (its behavior is ultimately predictable). It means that the h heading ecological engineering has not facilitated the proper interface between nature recom

use t and the environment. Modem environmental technology, for the most part, is based on an economy supported by nonrenewable (fossil fuel) energy; breaks, ease l been

P ecotechnology is based on the use of some nonrenewable energy at the start (the

word

has design and construction work by the ecological engineer) followed by ed.

hs, dependence on solar energy. insert ally

line lengt Ecosystem Conservation original work e h

t Ecological engineering involves identifying those biological systems that are most adaptable to human needs and those human needs that are most he original;

ion of adaptable to existing ecosystems. Ecological engineers have in their toolboxes t at o all of the ecosystems, communities, populations, and organisms that the world ue t r have been accident has to offer. Therefore, a direct consequence of ecological engineering is that it y t a would be counterproductive to eliminate or even disturb natural ecosystems represent m are

l unless absolutely necessary. This is analogous to the conservation ethic that is a shared by many farmers even though they may till the landscape. This suggests errors that the ecotechnology approach could lead to a greater environmental

age breaks conservation ethic than has been realized up to now. For example, when P is new digit

h wetlands were recognized for their ecosystem values of flood control and water pographic y iles. T t

quality enhancement, wetland protection efforts gained a much wider degree of f e ile: ng i f acceptance and even enthusiasm than they had before, despite their long- t F

D understood values as habitat for fish and wildlife (Mitsch and Gosselink, 1993). P peset and som

is In short, recognition of ecosystem y h t

ined, a bout A ret original t

ion. om

r values provides greater justification for the conservation of ecosystems. A ibut f r t cannot corollary of this observation is the point made by Aldo Leopold that the first r at not

o rule of a tinkerer is to not throw away any of the parts. The ecological engineer f is nature's tinkerer. however, version ng,

i t paper book, at ive COMPARISONS WITH EXISTING FIELDS at rm o riginal horit ic f

o Environmental Engineering e h t he aut

t Ecological engineering is not the same as environmental engineering, a

om r as ing-specif respected field that has been well established in universities and the workplace t ion

ed f since the early 1960s and was called sanitary engineering before that. peset

y Environmental engineers are certainly involved in the application of scientific principles to solve pollution problems, but the concepts usually involve energy publicat her t iles creat is and re-source-intensive operations such as settling tanks, scrubbers, filters, and h t L f chemical precipitators. Certainly, some techniques such as trickling falters M of

and ot

X could be considered ecological engineered approaches when they were om yles,

r conceived, but the field has gone far beyond designing ecosystems. It is f st version certainly possible that ecological engineering will develop in a partnership with environmental engineering, but the two fields remain distinct today. For print posed e

h interesting discussions of the differences and similarities between these two heading fields, see McCutcheon and Walski (1994), Mitsch (1994), and Odum (1994). recom use t breaks, ease l been

P Biotechnology

word has ed. Ecological engineering and its synonym "ecotechnology" should also not hs, be confused with biotechnology, which involves genetic manipulation to insert produce new strains and organisms to carry out specific functions. Some of the ally

line lengt differences between ecotechnology and biotechnology relate to their basic original work

e principles, control, design, and ultimate possible costs to society (see Mitsch h t

and Jørgensen, 1989b). Nevertheless, a comparison can be made between the development of ecotechnology and biotechnology. Ecotechnology is almost at he original; ion of t

at the stage where biotechnology was 20 years ago. Molecular biology was just o beginning then to establish the basic science and techniques for the yet unborn ue t r have been accident y t field of biotechnology. Today, ecology is recognized as a fundamental science a represent m

are and is now developing the ecosystem-level tools to develop the field of

l a ecotechnology. Despite the progress made in biotechnology (usually involving errors genetic manipulation of species), many researchers and environmental managers believe that it will not be a major factor in solving the world's age breaks

P environmental problems and that there may be some adverse environmental is new digit h pographic consequences from its development. Ecotechnology, which uses the existing y iles. T t

f e

ile: array of species, communities, and ecosystems of the earth, may receive more ng i f t

F attention as limitations of biotechnology are experienced. D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Restoration Fields ibut f r t cannot Restoration ecology has been described as "the full or partial replacement r at not o

f of structural or functional characteristics that have been extinguished or diminished and the substitution of alternative qualities or characteristics than however,

version the ones originally present with the proviso that they have more social, ng,

i t paper book, at ive economic, or ecological value than existed in the disturbed or displaced state" at rm (Cairns, 1988b). Several restoration fields have developed somewhat o riginal horit

ic f independently, and all appear to have the design of ecosystems as their theme. o

e Although related to ecological engineering or even a part of it, several of these h t he aut

t approaches seem to lack one of the two major criteria of ecological engineering,

om r as ing-specif namely (1) recognizing the self-designing ability of ecosystems or (2) basing t ion

ed f the approaches on a theoretical base, not just empiricism. Early work in Europe peset

y was based on the concept of bioengineering, the use of plants as engineering materials (Schiechtl, 1980). More recently, much has been written on publicat her t iles creat is restoration ecology (Aber and Jordan, 1985; Buckley, 1989; Jordan et al., 1987) h t L f and ecosystem rehabilitation (Cairns, 1988a; Wali, 1992). This approach has M of

and ot

X also been applied to river and stream restoration (Gore, 1985) and to agriculture om yles,

r as agroecosystems (Lowrance et al., 1984). f st version print posed

e CLASSIFICATIONS OF ECOLOGICALITY ENGINEERED h heading SYSTEMS recom use t breaks,

ease Classification According to Function l been P

word

has Ecological engineering, or ecotechnology, involves several approaches or ed.

hs, applications to the design of landscapes (Table 1). These applications range

insert from constructing new ecosystems for solving environmental problems to

ally ecologically sound harvesting of existing ecosystems. line lengt original work e h t Classification According to Structure he original;

ion of Early development of ecological engineering in the West has stressed a t at o partnership with nature and has been investigated primarily in experimental ue t r have been accident ecosystems rather than in full-scale applications. Some of the more significant y t a experiments that have been conducted or are currently under way in ecological represent m are

l engineering relate to aquatic systems, particularly shallow ponds and wetlands. a Ecological engineering as practiced in China has been applied to a wide variety errors of natural resource and environmental problems, ranging from fisheries and

age breaks agriculture to wastewater control and coastline protection. The emphasis in the P is new digit

h Chinese systems has been on applications rather than experimentation and on pographic y iles. T t

the production of food and fiber more than environmental protection (Mitsch, f e ile: ng i f 1991; Mitsch et al., 1993b). To simplify the variety of approaches and systems t F

D used in ecological engineering, Mitsch (1993) divided ecological engineering P peset and som

is case studies into three categories: y h t

ined, a bout A ret original t

ion. om r

ibut TABLE 1 Classification and Examples of Ecological Engineering According to f r t cannot Types of Applications r at not o Application Examples f Ecosystems are used to reduce or solve Wastewater recycling in wetlands; sludge

however, a pollution problem that otherwise recycling version ng,

i would be harmful to other ecosystems. t paper book, at ive Ecosystems are imitated or copied to Reconstructed wetlands; integrated at rm reduce or solve a resource problem. fishponds o riginal

horit The recovery of an ecosystem is Surface coal mine restoration; lake and ic f

o supported after significant disturbance. river restoration; restoration of hazardous e h waste sites t he aut t Existing ecosystems are modified in an Biomanipulation of fish in reservoirs; om r as ing-specif

t ecologically sound way to solve an biological control of eutrophication ion

ed f environmental problem. symptoms

peset Ecosystems are used for the benefit of Sustainable agroecosystems; sound y humans without destroying the renewable resource harvesting publicat

her t ecological balance. iles creat is h t L f

M of

SOURCE: From Jørgensen and Mitsch (1989). and ot X om yles, r f 1. Mesocosms st version 2. Ecosystems print posed 3. Regional systems e h heading Examples of systems in each of these categories are given in Table 2. recom

use t Mesocosms are generally artificially enclosed systems (sometimes called closed

breaks, systems) but can range in size from laboratory bench-size systems to Biosphere ease l been

P 2 in Arizona. Much of our understanding of ecosystem behavior can come from

word

has the construction of scale-model ecosystems. Scale models of ecosystems ed. hs, (microcosms and mesocosms) have been built around the world (Beyers and

insert Odum, 1993), including scale models of both the Everglades and Chesapeake

ally Bay (Adey and Loveland, 1991) and experimental mesocosms to investigate the line lengt

original work role of hydroperiods (the fluctuation in water level over time) on nutrient and e h

t metal retention in marshes (Busnardo et al., 1992; Sinicrope et al., 1992).

Ecosystem applications have been dominated by wetlands and water pollution he original;

ion of control ecosystems; the ecosystem is probably the scale for which we have the t at o most examples of ecological engineering today. Regional systems involve the ue t r have been accident construction or restoration of a multiplicity of ecosystems that are all y t a interconnected in reinforcing patterns and pathways. Many examples of this represent m are

l type of system are found in China where human nutrition is tied into a a

errors functional ecosystem or set of ecosystems.

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. http://www.nap.edu/catalog/4919.html Engineering WithinEcologicalConstraints About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication as the authoritative version for attribution. ECOLOGISTS FOR ANEW ENGINEERING: ENGINEERS AND ECOLOGICAL PARADIGM TABLE 2 Classification and Examples of Ecological Engineering Case Studies at Mesocosm, Ecosystem, and Regional Scales Ecological Engineering Project Location Purpose References Mesocosm (Closed System) Treatment of septage wastes Harwich, Massachusetts Produce clean water (drinking water Teal and Peterson (1991, 1993)

Copyright © National Academy ofSciences. Allrights reserved. standards) from septage from an unlined landfill lagoon Biosphere 2 Oracle, Arizona Simulate planet earth and investigate Nelson et al. (1993) possible space habitation Ecosystem Experimental estuarine ponds Morehead City, North Carolina Investigate estuarine ponds receiving Odum (1989b) a mixture of wastewater and salt water Forested wetlands for recycling Gainesville, Florida Experimentally investigate forested Odum et al. (1977); Ewel and cypress domes for wastewater Odum (1984) recycling and conservation Root-zone wetlands for wastewater Throughout Europe Investigate use of root-zone wetlands Brix (1987); Gumbricht (1992) treatment to provide tertiary treatment of wastewater Renovation of coal mine drainage Coshocton County, Ohio Study iron retention from coal mine Fennessy and Mitsch (1989) drainage with Typha wetland River pollution control Suzhou, China Use water hyacinths (Eichhornia Ma and Yan (1989) crassipes) for water pollution control and production of fodder Heavy metal removal from soils Copenhagen, Denmark Use plants and EDTA to remove metals Jørgensen (1993) Forest reconstruction Throughout Japan Develop dense stands of woody Miyawaki and Galley (1993) vegetation to hide industrial complexes, control visual, noise, and chemical pollution, stabilize soil, and provide urban green space 121 http://www.nap.edu/catalog/4919.html Engineering WithinEcologicalConstraints About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication as the authoritative version for attribution. ECOLOGISTS FOR ANEW ENGINEERING: ENGINEERS AND ECOLOGICAL PARADIGM Ecological Engineering Project Location Purpose References Region Restoration of riparian landscape Lake County, Illinois Restore midwestern U.S. river Hey et al. (1989) floodplain and determine design

Copyright © National Academy ofSciences. Allrights reserved. procedures for restored wetlands Phosphate mine restoration Central Florida Reconstruct wetland/upland landscape Brown et al. (1992) at phosphate mine Agro-Ecological Engineering Several hundred sites in China Incorporate multiple-product farming Ma et al. (1988); Yan et al. (1993) with extensive recycling Fish production/wetland systems Yixing County, Jiangsu Province, Produce fisheries synchronized to Mitsch (1991) China Phragmites wetland production and harvesting Salt marsh restoration China's east coast, esp. Wenling, Develop Spartina marshes on former Chung (1993) Zhejiang Province barren coastline for shoreline protection and food and fuel production Integrated tree-livestock system Somalia Develop Acacia albida crop-livestock Unruh (1993) system 122 Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ECOLOGICAL ENGINEERING: A NEW PARADIGM FOR ENGINEERS AND 123 ECOLOGISTS e h t be

ion. om

r IMPORTANCE TO ECOLOGY AND ENVIRONMENTAL ibut f r t cannot MANAGEMENT r at not o

f The need for ecological engineering is evident in the following arguments:

however, 1. The state of the environment, combined with a dwindling of version ng,

i nonrenewable natural resources available to solve environmental t paper book, at ive problems, suggests that the time has come for a new paradigm in at rm

o engineering that deals with questions and solutions on the scale of riginal horit ic f ecosystems and landscapes. There are a great number of environmental o e

h and resource problems that need an ecosystem approach, not just a t he aut t standard technological solution. Ecotechnology will play a significant role om r as ing-specif t in a sustainable society. Since we cannot solve all of our environmental ion ed f problems with technological solutions alone and since our energy future is peset

y clouded, we need to investigate alternative means of cleaning the

publicat environment. her t iles creat is

h 2. Many current solutions to environmental problems are part of a "shell t L f

M of game." We control one kind of pollution, such as water pollution, to find

and ot X that we have another kind of problem, such as a waste disposal problem om yles, r

f on land. Little attention is paid to ecologically sound approaches that st version consider both direct and indirect effects. print

posed 3. Ecological engineering is currently being practiced by many professions e h

heading under a great variety of names, including ecotechnology, ecosystem

recom restoration, artificial ecology, biomanipulation, ecosystem rehabilitation, use t nature engineering (in Holland), and bioengineering (originated in breaks, ease l been Germany) but with little theory to back the practices. Engineers are P

word building wetlands, lakes, and rivers with little understanding of the has ed.

hs, biological integrity of these systems. Ecologists and landscape architects

insert now design ecosystems with homespun methodologies that must be relearned each time. Engineers who design ecosystems relearn the ally

line lengt approaches each time and do not generally publish their successes in the original work e open literature. The theory has not yet connected with the practice. h t 4. Engineering and ecology are ripe for integration into one field and should

he original; not remain separate approaches that are often adversarial. Ecology as a ion of t at o science is not routinely integrated into engineering curricula, even in

ue t environmental engineering programs. Engineers are missing the one r have been accident y t

a science that could help them the most in environmental matters. Likewise, represent m are

l environmental scientists and managers are missing the tremendously a effective engineering approach in their problem solving. The basic errors science of ecological engineering is ecology, a field that has now matured to the point that it needs to have a prescriptive—rather than just a age breaks P is new digit descriptive—aspect. h pographic y iles. T

t 5. Engineers now need, more than ever, a better understanding of ecological

f e ile:

ng concepts and limitations in their daily practice, particularly if they deal i f t F with natural systems. For example, an important aspect of ecological D P

peset engineering, the application of self-design (i.e., Mother Nature as the and som is y h t general contractor and chief engineer), is a decided departure from most

ined, traditional engineering. Engineering a bout A ret original t

ion. om

r to this point in history has been interested in designing totally predictable ibut f r t cannot systems with little left to chance or the vagaries of nature. r at not

o 6. The idea of nature conservation is so important that it needs to become a f goal of engineering, not just one of its possible outcomes. however, version ng,

i t paper book, at ive Short- and Long-Term Impact of Ecological Engineering at rm o In the short-term, ecotechnology could bring immediate attention to the riginal horit ic f

o importance of ''designing and building ecosystems'' as a logical extension of the e h field of ecology as it applies directly to solving environmental problems. In the t he aut t

om long-term, ecotechnology will provide the basic and applied scientific results r as ing-specif t needed by environmental regulators and managers to control some types of ion ed f pollution while reconstructing the landscape in an ecologically sound way. The peset y formalization of the idea that natural ecosystems have values for humans, other publicat

her t than directly commercial ones, is also a benefit of ecotechnology and will go a iles creat is h

t long way toward promoting an environmental conservation ethic and preserving L f

M of

and ot biodiversity. X Specifically, ecotechnology will contribute to an improved environment in om yles, r f the long-term in several ways: st version 1. In the future we will be faced with climate changes, disappearing print posed e wetlands, degraded forests, and polluted lakes and coastal waters. A h heading combination of adaptation and prevention may be the most appropriate recom

use t strategy. Ecotechnology will provide environmental managers with the

breaks, tools needed to facilitate adaptation of natural and human systems to these ease l been P

changes. word has

ed. 2. Major land use changes such as surface mining and the draining of hs, wetlands continue to alter the landscape. Wetland mitigation and surface insert mine reclamation are generally approached empirically, with little

ally bridging to the theory of ecosystem function. The emphasis on line lengt

original work fundamental work as a basis of ecological engineering will provide e h t

ecological theory to support and refine current empirical approaches. 3. Ecotechnology will be needed as environmental agencies begin to clean he original; ion of

t up the environment through conventional approaches. The restoration of at o dumps for solid and hazardous waste, the reintroduction of fish and other ue t r have been accident

y aquatic organisms in recently improved streams, rivers, lakes, and t a reservoirs, and the recovery of forests with the reduction in acid represent m are

a precipitation all require ecological engineers who know which species to errors

reintroduce. age breaks P is new digit Recent Developments h pographic y iles. T t

e There are some signs that ecotechnology will become prominent in ile: ng i f t research communities in the near future and may well serve as the newest F

D frontier of ecological science. Research support is generally increasing for P peset and som is y fields related to h t

ined, a bout A ret original t

ion. om

r ecological engineering, including ecosystem restoration and biomanipulation ibut f r t cannot (Department of Energy, Department of Defense, National Science Foundation), r at not

o wetland design and experimentation (Environmental Protection Agency [EPA], f U.S. Army Corps of Engineers, Department of Transportation), reservoir and

however, lake restoration (U.S. Fish and Wildlife Service, state agencies), nonpoint version ng,

t source water pollution control (EPA and Department of Agriculture [USDA]), paper book, at ive forest recovery (USDA Forest Service), and sustainable agroecosystems at rm o (USDA). riginal horit ic f

o The first known international ecological engineering conference, held in e h Trosa, Sweden (Etnier and Guterstam, 1991), highlighted many of the t he aut t

om applications of indoor and outdoor ecological engineering wastewater systems. r as ing-specif t This was followed by a workshop in May 1993 sponsored by the National ion ed f Research Council of the National Academy of Sciences in Washington, D.C. peset y Two new journals—Ecological Engineering and The Journal of Ecotechnology publicat

her t and Ecological Restoration—have been launched in the past three years. iles creat is h

t SCOPE (Scientific Committee on Problems of the Environment), with the L f

M of

and ot encouragement of the U.S. National Academy of Sciences, has approved a X multiyear, three-continent workshop project entitled Ecological Engineering om yles, r f and Ecosystem Restoration. A society for ecological engineers is beginning to st version form in Europe. The dialogue between environmental engineers and ecological print posed

e engineers has begun with joint editorials in 1994 in the Journal of h heading Environmental Engineering and Ecological Engineering (see McCutcheon and recom

use t Walski, 1994; Mitsch, 1994; Odum, 1994). Ecological engineering programs in academia are being discussed in a breaks, ease l been

P variety of departments and programs at the Ohio State University, University of

word

has Illinois, University of Maryland, and University of Florida. Students have read ed.

hs, the new literature on the field and are eager to find universities that have

insert integrated programs in this new field. Professional certification issues must be

ally addressed, but ecologists, noticing the professional stature of engineering, have line lengt developed at least one certification program for professional ecologists original work e h

t (Ecological Society of America Professional Certification) and at least two for wetland specialists (Society of Wetland Ecologists and U.S. Army Corps of he original;

ion of Engineers). t at o ue t r have been accident y t CONCLUSIONS a represent m are

l The integration of ecology into an application that some ecologists have a chosen to call ecological engineering, or ecotechnology, has not yet taken place errors to as great a degree as might be expected, given the great public concern for

age breaks major environmental problems. Compared with graduates in engineering, P is new digit

h graduates in ecology remain near the start of the learning curve when pographic y iles. T t

f confronted with real-life issues of wetland construction, river restoration, e ile: ng i f habitat reconstruction, or mine land rehabilitation. They often rise to the t F

D occasion quickly with homespun ecotechnology and novel approaches, but they P peset and som

is must continually relearn techniques that work. Engineers, on the other hand, y h t

know hydrology, physical sciences, and design principles, but are not well ined,

a versed in the ecology necessary bout A ret original t

ion. om

r to understand, predict, and build ecosystems. While ecological theory may be ibut f r t cannot mentioned, it has usually not been integrated into a framework that could be r at not

o provided by ecological engineering. Furthermore, ecotechnology is, by f definition, a combination of basic and applied research and requires

however, interdisciplinary teams for its proper application. The development of such a version ng,

t discipline will require cooperative efforts from many related fields, and the paper book, at ive fruitful integration of these efforts will need a new administrative structure in at rm o universities and research laboratories for this cross-fertilization of fields to riginal horit ic f

o prosper. The development of the field requires more discussion and e h interdisciplinary interaction among both engineers and ecologists. t he aut t

om r as ing-specif t ion

ed f REFERENCES peset

y Aber, J. D., and W. R. Jordan III. 1985. Restoration ecology: An environmental middle ground. BioScience 35:399. publicat her t iles creat

is Adey, W., and K. Loveland. 1991. Dynamic Aquaria: Building Living Ecosystems. San Diego, h t L f Calif.: Academic Press. M of

Beyers, R. J., and H. T. Odum. 1993. Ecological Microcosms. New York: Springer-Verlag. and ot

X Bradshaw, A. D. 1987. Restoration: The acid test for ecology. Pp. 23-29 in Restoration Ecology: A

om Synthetic Approach to Ecological Research, W. R. Jordan III, M. E. Gilpin, and S. D. yles, r f

st Abet, eds. Cambridge, England: Cambridge University Press. version Brix, H. 1987. Treatment of wastewater in the rhizosphere of wetland Plants—The root zone method. Water Science and Technology 19:107-118. print posed e Brown, M. T., R. E. Tighe, T. R. McClanahan, and R. W. Wolfe. 1992. Landscape reclamation at a h heading central Florida phosphate mine. Ecological Engineering 1:323-354.

recom Buckley, G. P., ed. 1989. Biological Habitat Reconstruction. London: Belhaven Press. use t Busnardo, M. J., R. M. Gersberg, R. Langis, T. L. Sinicrope, and J. B. Zedler. 1992. Nitrogen and

breaks, phosphorus removal by wetland mesocosms subjected to different hydroperiods. ease l been

P Ecological Engineering 1:287-307.

word Cairns, J. Jr., ed. 1988a. Rehabilitation of Damaged Ecosystems, Volumes I and II. Boca Raton, has ed. Fla.: CRC Press. hs, Cairns, J. Jr. 1988b. Restoration ecology: The new frontier. Pp, 1-11 in Rehabilitation of Damaged

insert Ecosystems, Volumes I and II, J. Cairns Jr., ed. Boca Raton, Fla: CRC Press. Chung, C.-H. 1993. Thirty years of ecological engineering with Spartina plantations in China. ally

line lengt Ecological Engineering 2:261-289.

original work Etnier, C., and B. Guterstam, eds. 1991. Ecological engineering for wastewater treatment. e h

t Proceedings of the International Conference, March 24-28, 1991, Trosa, Sweden. Gothenburg, Sweden: Bokskogen. Ewel, K. C., and H. T. Odum, eds. 1984. Cypress Swamps. Gainesville, Fla. : University Presses of he original; ion of

t Florida. at o Fennessy, M. S., and W. J. Mitsch. 1989. Treating coal mine drainage with an artificial wetland.

ue t Research Journal of the Water Pollution Control Federation 61:1691-1701. r have been accident y t Gore, J. A., ed. 1985. The Restoration of Rivers and Streams. Boston: Butterworth. a Gumbricht, T. 1992. Tertiary wastewater treatment using the root-zone method in temperate represent m are

l climates. Ecological Engineering 1:199-212. a Guterstam, B., and J. Todd. 1990. Ecological engineering for wastewater treatment and its errors application in New England and Sweden. Ambio 19:173-175. Haeckel, E. 1866. Generelle Morphologic der Organismen. Bd. H Reimer, Berlin. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Hey, D. L., M. A. Cardamone, J. H. Sather, and W. J. Mitsch. 1989. Restoration of riverine r ibut f r wetlands: The Des Plaines River wetland demonstration project. Pp. 159-183 in Ecological t cannot Engineering: An Introduction to Ecotechnology, W. J. Mitsch and S. E. Jørgensen, eds. r at not

o New York: John Wiley & Sons. f Jordan, W. R. III, M. E. Gilpin, and J. D. Aber, eds. 1987. Restoration Ecology: A Synthetic Approach to Ecological Research. Cambridge, England: Cambridge University Press. however, Jørgensen, S. E., and W. J. Mitsch. 1989. Classification and examples of ecological engineering. Pp. version ng,

t 13-19 in Ecological Engineering: An Introduction to Ecological Engineering, W. J. Mitsch paper book, at ive and S. E. Jørgensen, eds. New York: John Wiley & Sons. at rm Jørgensen, S. E. 1993. Removal of heavy metals from compost and soil by ecotechnological o

riginal methods. Ecological Engineering 2:89-100. horit ic f

o Lowrance, R., B. R. Stinner, and G. J. House, eds. 1984. Agricultural ecosystems: Unifying e

h concepts. New York: John Wiley & Sons. t he aut t

Ma Shijun. 1985. Ecological engineering: Application of ecosystem principles. Environmental om r

as Conservation 12:331-335. ing-specif t Ma Shijun. 1988. Development of Agro-Ecological Engineering in China. Pp. 1-13 in Proceedings ion ed f of the International Symposium on Agro-Ecological Engineering, August 1988, Ma peset

y Shijun, Jiang Ailiang, Xu Rumei, and Li Dianmo, eds. Beijing: Ecological Society of China. Ma Shijun, Jiang Ailiang, Xu Rumei, and Li Dianmo, eds. 1988. Proceedings of the International publicat

her t Symposium on Agro-Ecological Engineering, August 1988. Beijing: Ecological Society of iles creat is

h China. t L f Ma Shijun and Yan Jingsong. 1989. Ecological engineering for treatment and utilization of M of

and ot

X wastewater. Pp. 185-217 in Ecological Engineering: An Introduction to Ecotechnology, W. J. Mitsch and S. E. Jørgensen, eds. New York: John Wiley & Sons. om yles, r f McCotcheon, S.C., and T. M. Walski. 1994. Ecological engineering: Friend or foe? Ecological st version Engineering 3:109-112. Mitsch, W.J. 1991. Ecological engineering: Approaches to sustainability and biodiversity in the U.S. print posed

e and China. Pp. 428-448 in Ecological Economics: The Science and Management of h

heading Sustainability, R. Costanza, ed. New York: Columbia University Press.

recom Mitsch, W.J. 1993. Ecological engineering—A cooperative role with the planetary life-support

use t systems. Environmental Science & Technology 27:438-445.

breaks, Mitsch, W.J. 1994. Ecological engineering: A friend. Ecological Engineering 3:112-115. ease l been Mitsch, W. J., and S. E. Jørgensen, eds. 1989a. Ecological Engineering: An Introduction to P Ecotechnology. New York: John Wiley & Sons. word has ed. Mitsch, W. J., and S. E. Jørgensen. 1989b. Introduction to ecological engineering. Pp. 3-12 in hs, Ecological Engineering: An Introduction to Ecotechnology, W. L Mitsch and S. E.

insert Jørgensen, eds. New York: John Wiley & Sons. Mitsch, W. J., and J. G. Gosselink. 1993. Wetlands, 2nd ed. New York: Van Nostrand Reinhold. ally Mitsch, W. J., J. Yan, and J. Cronk, eds. 1993a. Ecological engineering in China. Special Issue of line lengt

original work Ecological Engineering 2:177-307. e

h Mitsch, W. J., J. Yan, and J. Cronk. 1993b. Ecological engineering—Contrasting experiences in t China with the West. Ecological Engineering 2:177-191. Miyawaki, A., and F. B. Golley. 1993. Forest reconstruction as ecological engineering. Ecological he original;

ion of Engineering 2:333-345. t at o Nelson, M., T. L. Burgess, A. Ailing, N. Alvarez-Romo, W. F. Dempster, R. L. Walford, and J. P. Allen. 1993. Using a closed ecological system to study Earth's biosphere—Initial results ue t r have been accident y

t from Biosphere 2. BioScience 43:225-236. a New Discipline of Ecological Engineering Faces a Lack of Funding by Major Agencies (article). represent m are

l 1993. Environmental Science & Technology 27(7):1245. a Odum, H.T. 1962. Man in the Ecosystem. Proceedings of Lockwood Conference on the Suburban errors

Forest and Ecology, Bulletin of the Connecticut Agricultural Station 652:57-75. age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Odum, H.T. 1971. Environment, Power, and Society. New York: John Wiley & Sons. r ibut f r Odum, H.T. 1989a. Ecological engineering and self-organization. Pp. 79-101 in Ecological t cannot Engineering: An Introduction to Ecotechnology, W.J. Mitsch and S. E. Jørgensen, eds. r at not

o New York: John Wiley & Sons. f Odum, H.T. 1989b. Experimental study of serf-organization in estuarine ponds. Pp. 291-340 in Ecological Engineering: An Introduction to Ecotechnology, W. J. Mitsch and S. E. however, Jørgensen, eds. New York: John Wiley & Sons. version ng,

t Odum, H.T. 1994. Ecological engineering: The necessary use of ecological serf-design. Ecological paper book, at ive Engineering 3:115-117. at rm Odum, H. T., W. L. Siler, R. J. Beyers, and N. Armstrong. 1963. Experiments with engineering of o

riginal marine ecosystems. Publication of the Institute of Marine Science of the University of horit ic f

o Texas 9:374-403. e

h Odum, H. T., K. C. Ewel, W. J. Mitsch, and J. W. Ordway. 1977. Recycling treated sewage through t he aut t

cypress wetlands. Pp. 35-67 in Wastewater Renovation and Reuse, F. M. D'Itri, ed. New om r

as York: Marcel Dekker Press. ing-specif t Qi Ye and Tian Han-qin. 1988. Some views on ecosystem design. In Proceedings of the ion ed f International Symposium on Agro-Ecological Engineering, August, 1988, Ma Shijun, peset

y Jiang Ailiang, Xu Rumei, and Li Dianmo, eds. Beijing: Ecological Society of China. Schiechtl, H. 1980. Bioengineering for land reclamation and conservation. Edmonton, Alberta, publicat

her t Canada: The University of Alberta Press. iles creat is

h Sinicrope, T.L., R. Langis, R. M. Gersberg, M. J. Busnardo, and J. B. Zedler. 1992. Metal removal t L f by wetland mesocosms subjected to different hydroperiods. Ecological Engineering M of

and ot

X 1:309-322. Straskraba, M. 1993. Ecotechnology as a new means for environmental management. Ecological om yles, r f Engineering 2:311-331. st version Straskraba, M., and A. H. Gnauck. 1985. Freshwater Ecosystems: Modeling and Simulation. Amsterdam: Elsevier. print posed

e Teal, J. M., and S. B. Peterson. 1991. The next generation of septage treatment. Research Journal of h

heading the Water Pollution Control Federation 63:84-89.

recom Teal, J. M., and S. B. Peterson. 1993. A solar aquatic system septage treatment plant. Environmental

use t Science & Technology 27:34-37.

breaks, Unruh, J. D. 1993. An Acacia-based design for sustainable livestock carrying capacity on irrigated ease l been farmlands in semi-arid Africa. Ecological Engineering 2:131-148. P Wali, M. K., ed. 1992. Environmental Rehabilitation: Preamble to Sustainable Development, 2 word has ed. Volumes, The Hague, Netherlands: SPB Academic Press. hs, Yan Jingsong and Yao Honglu. 1989. Integrated fish culture management in China . Pp. 375-408 in

insert Ecological Engineering: An Introduction to Ecotechnology, W. J. Mitsch and S. E. Jørgensen, eds. New York: John Wiley & Sons. ally Yan Jingsong and Zhang Yushu. 1992. Ecological techniques and their application with some case line lengt

original work studies in China. Ecological Engineering 1:261-285. e

h Yan Jingsong, Zhang Yushu, and Wu Xinyuan. 1993. Advances of ecological engineering in China. t Ecological Engineering 2:193-215. he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not Why Aren't All Engineers Ecologists? o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Albert H. Wurth, JR. t he aut t

om r as

ing-specif "What is Engineering? The control of nature by man. Its motto is the primal one t —'Replenish the earth and subdue it'.... Is there a barren desert—irrigate it; is ion ed f

peset there a mountain barrier—pierce it; is there a rushing torrent—harness it. y Bridge the rivers; sail the seas; apply the force by which all things fall, so that publicat

her t it shall lift things.... Nay, be 'more than conqueror' as he is more who does not iles creat is h

t merely slay or capture, but makes loyal allies of those whom he has overcome! L f

M of

Appropriate, annex, absorb, the powers of physical nature into human nature!" and ot X Rossiter W. Raymond1 — 1913 om yles, r f st version ECOLOGY AND ENGINEERING print posed e h

heading The modifications made to the environment by human activity have been

recom anthropocentric, directed at adapting natural systems to human needs and wants. use t The scale and scope of human intervention in natural systems have increased breaks, ease l been with growing capacity for engineering, but it is difficult to argue that this P

word increase has been pursued for its own sake. Put another way, though we have has ed.

hs, relentlessly attempted to "improve" on nature, the undesirable effects of this

insert effort have been caused not so much by hostility toward natural systems as by a lack of careful attention to them.2 Pollution, resource depletion, and ally

line lengt environmental degradation have not been desired outcomes. Rather, such original work e impacts have increased as "side-effects" of improved production. Engineers h t have sought faster transportation, better shelter, improved communication, and

he original; more efficient processes, not more pollution or development pressure on natural ion of t at o areas.

ue t The almost inadvertent character of the impact of engineering on natural r have been accident y t

a systems has made it difficult for the engineering discipline to recognize and represent m are

l address issues like sustainability. In fact the source of the concern about the a sustainability of natural systems in the face of ongoing human modifications errors has emerged primarily from another quarter, the work of the ecologists. Current concern for ecological sustainability focuses especially on the long- age breaks P is new digit term and less-apparent costs of human modifications, on the counterproductive h pographic y iles. T

t effects or "unintended consequences" of human activity, on paying attention to

f e ile:

ng the "by-products" (costs to natural systems) as well as the products (benefits to i f t F humans) of our technological system. These concerns have been brought to the D P peset and som is y h t

ined, a bout A ret original t

ion. om

r fore by the work of ecologists, who attempt to analyze ecosystems as wholes ibut f r t cannot and investigate interactions and other effects in natural systems not immediately r at not

o apparent to humans. From the ecologists' perspective, which unlike the f engineers' does not begin with human wants and needs, concepts like "side-

however, effects" or distinctions between products and by-products are difficult to version ng,

t incorporate into ecosystem analyses. Natural systems or ecosystems are studied, paper book, at ive at least in theory, in terms of their overall operation, not their productivity for at rm o human wants and needs. Thus, the different attitudes of engineering and riginal horit ic f

o ecology toward natural systems can be attributed to their different starting points. e h Steven L. Goldman has underscored these differences in approach between t he aut t

om engineering and science. He contrasts engineering's theoria, that is, "its r as ing-specif t characteristic world-view and rationality" with the theoria of the physical ion ed f sciences (1990, p. 125). Engineering is distinguished by its grounding in context peset y and valuation, with its emphasis on design; science seeks to understand publicat

her t universal and independent natural systems, with a focus on discovery. As iles creat is h

t Goldman notes, "the problems addressed by the sciences are ... supposed to be L f

M of

and ot given to them by 'Nature'.... Within the practice of science, scientific problems X are commonly conceived of as discovered; they are not arbitrary human om yles, r f inventions" (p. 129). On the other hand, "engineering problems are overtly st version invented.... given to engineers not by a supposed independently existing Nature, print posed

e but by people who have, for a variety of generally obvious ulterior motives, h heading invented them" (p. 130).3 recom

use t These differences, however, can be overstated. The emphasis on design in engineering, while perhaps distinct from the focus of analytic physical sciences, breaks, ease l been

P is less incompatible with ecological science. This paper is offered as an

word

has argument that ecologists and engineers have a great deal in common, and that ed.

hs, recognition of that common ground offers significant opportunity for a new

insert twenty-first century synthesis that could give energy and direction to the quest

ally for sustain-ability. line lengt original work e h t ENGINEERING STUDENTS AND ECOLOGY he original;

ion of The impetus for this paper came from a recognition of a recurring t at o phenomenon in my course in environmental politics. It seemed that every time ue t r have been accident the course, a political science course in the College of Arts and Sciences, has y t a been offered, some of the best and most engaged students have been represent m are

l engineering students. While part of this phenomenon can, no doubt, be a attributed to the fact that many of these individuals have been excellent students errors who have performed well in all their classes, it has always seemed that these

age breaks students not only have done well in all aspects of class performance, but also P is new digit

h have exhibited genuine interest in ecology and environmental issues. In short, it pographic y iles. T t

has been my impression that these engineering students seem to display a f e

ile: 4 ng i f particular attraction to, or affinity for, the course material. t F

D While the historical and philosophical writings in the course are also popular P peset and som is y h t

ined, a bout A ret original t

ion. om

r with the students, the readings and arguments that seem to have the most impact ibut f r t cannot on the engineers tend to be the ones that deal with ecology and resource use. In r at not

o particular, classic environmental analyses that use concepts familiar to f engineers like entropy and systems (e.g., Boulding, 1993; Georgescu-Roegen,

however, 1993), studies using models (Meadows et al., 1992), and energy analyses version ng,

t emphasizing efficiency (especially Lovins et al., 1986) seem to have particular paper book, at ive appeal with the engineering students. at rm o The enthusiasm of the engineering students suggests that there are aspects riginal horit ic f

o of ecological and environmental analyses that have an inherent attractiveness to e h students of engineering. A quick analysis suggests where this appeal might lie. t he aut t

om r as ing-specif t ion

ed f ENGINEERING AND ECOLOGICAL SYSTEMS peset y A discipline like engineering, focused on material balances, production publicat

her t efficiency, and waste minimization will very likely be attuned to the inputs iles creat is h t

L f (resources) and outputs (product and waste) of the systems it engineers. Indeed,

M of

and ot an emphasis on efficiency of resource use and waste reduction is inherent to the X engineering project. Ecologists seem to have a strikingly similar focus in the om yles, r f necessary inputs, efficiencies, production, maintenance, and waste handling of st version the ecosystems they study.5 Despite their differences in theoria, their pursuits print posed

e and subject matters have marked similarities. Both ecology and engineering h heading seek to understand the integration of components of systems to produce recom

use t functional wholes. This approach actually equips the engineer to be receptive to ecosystem models, because ecosystems, like artifacts, have to work; their parts breaks, ease l been 6

P have to fit together.

word

has If the engineers and ecologists share an interest in working systems, why is ed.

hs, it that the two disciplines often assume conflicting positions on issues? Indeed,

insert one primary force that has contributed to the intrusion of human activity on the

ally ecological systems of the natural environment has been the growth of line lengt engineering. Despite their affinities, the directions taken in the real world by the original work e h

t two disciplines have tended to place practitioners at odds rather than to emphasize their common practice. he original;

ion of Given their similarities in orientation, the divergence of the two disciplines t at o seems to be artificially constructed by the professional, educational, and social ue t r have been accident influences on the two fields. Despite their shared concerns with systems, the y t a ecologist's definition is an expansive one, attempting to explore and understand represent m are

l a complex network, while the engineer's has been much more susceptible to a constraints on both the size and character of the particular system and on the errors relevant inputs and outputs. Here, Goldman's argument about engineering's

age breaks distinct theoria again helps explain the engineering approach. P is new digit

h Nevertheless, despite the differences in the two disciplines' treatments of pographic y iles. T t

f relevant or important components and limits of the system being studied, the e ile: ng i f understanding of the nature of a system, and thereby of an ecosystem, should be t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r much more familiar terrain for an engineer than, say, for an economist or a ibut f r t cannot politician. r at not

o Indeed, engineers are well equipped to understand impacts of human f activity on ecosystems; any reasonably complete materials balance analysis of a

however, manufacturing process reflects the fact that car manufacturers produce more version ng,

t than cars, that steelmakers make more than steel, and that nuclear plants paper book, at ive generate more than electricity. The profession we would most likely charge at rm o with determining the impact of a year's production of automobiles on air and riginal horit ic f

o fuel resources would be engineers. e h This basic understanding of physical processes and materials balances t he aut t

om clearly equips engineers to identify stresses to ecosystems. Their grounding in r as ing-specif t real-world inputs and outputs makes engineers less susceptible, at least on a ion ed f theoretical level, to ignoring real costs of the industrial system (like pollution). peset y The externalities, or uncounted costs of production, that economists quibble publicat

her t over have real measurability to engineers (valuation is another issue—see iles creat is h

t below); no engineer believes that smoke goes "away." L f

M of

and ot X om yles,

r ENGINEERING AND POLITICS f st version Still, it would be a mistake to overestimate the capacity of engineers to print posed

e apply ecological models to the systems they design. There is a reason that the h heading engineer's attention is not turned toward the same overall analysis of a system recom

use t that an ecologist might perform. While Goldman (1991) has called this the "social captivity of engineering," I would prefer to use a language that might be breaks, ease l been

P even less familiar, namely, that political decisions determine the approach taken

word

has to the technical analysis made by an engineer. Here, the definition of politics is ed.

hs, much broader than the conventional "activity of the government" that so often

insert defines American images of politics. The politics is the capacity to make

ally decisions that shape or constrain the lives of others, the possibility to exert line lengt power over others. To the extent that, as Goldman argues, the decisions about original work e h

t which systems to investigate and which to avoid, or which variables must be carefully monitored and which can be ignored, are made by "managers," these he original;

ion of managers inform, or hold captive, the engineering practice. t at o This captivity is an undeniably political (in the broadest sense) constraint. ue t r have been accident Goldman sees these "managers" as employers, government agencies, other y t a institutional authorities who define the practice of engineering in context, represent m are

l making it "a decision-dominated, rather than a (technical) knowledge- a dominated process" (1991, p. 122). So rather than finding the natural boundaries errors of the ecosystem, the engineer is trained to accept the project or system as

age breaks defined by the manager. Which costs count and which do not is a decision made P is new digit

h in terms of social values determined by the culture, the economic system, and pographic y iles. T t

the preferences of the decision makers. Inputs and outputs are not measured in f e ile: ng i f terms of their impact on t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r natural systems or their sustainability unless those values are included in the ibut f r t cannot constraints imposed by the managers. r at not

o Thus, the environmental impacts and side-effects of engineering practice f have occurred not because of engineering's inherent tendency to ignore

however, ecological constraints. Sustainability is not necessarily at odds with engineers' version ng,

t efforts. Engineers work under the conditions set by the political decision paper book, at ive makers, those with the power to define the engineer's problem and to set the at rm o constraints on its solution. Much as the political scientist E. E. Schattschneider riginal horit ic f

o (1975) has argued about political agendas, the questions asked delimit and e h determine the answers provided. t he aut t

om The political constraints that limit engineers' attention to ecosystem effects r as ing-specif t are many and various. The most obvious are economic—in market systems, ion ed f services of nature are underpriced, and all externalities or social costs are, by peset y definition, misvalued. Monetary, not ecological, cost drives engineering design. publicat

her t In practice, the bulk of this power lies in the hands of the economic decision iles creat is

h 7 t

L f makers in the business world.

M of

and ot But the design parameters for engineers can be ecologically wrongheaded X for a variety of other reasons besides inaccurate estimate of environmental om yles, r f externalities. As Herman Daly and John Cobb have argued, the sheer scale of st version the impact of the engineered world has a cumulative effect in relation to the print posed

e ecosystem, so it is not simply a matter of better estimating the conditions h heading imposed on engineering to reflect more accurately costs that had previously recom

use t been ignored. As Daly and Cobb note, "the price system, with marginal Pigovian adjustments [for externalities], leads to an optimal allocation of a breaks, ease l been

P given resource flow, whatever its scale happens to be. But the price system does

word

has not lead to the optimal scale" (1989, p. 144). New scale constraints must be ed.

hs, acknowledged.8 The relative size of the industrial and engineered world in

insert relation to the ecosystem that supports it must be recognized. "Continuous

ally growth in the scale of the aggregate economy could only make sense in the line lengt context of an unlimited environment" (Daly and Cobb, 1989, p. 145). original work e h

t Similarly, even accurate pricing does not deter certain kinds of politically popular engineering enterprises, like nuclear weapons, space programs, defense he original;

ion of systems, and other governmental programs criticized by detractors as pork t at o barrel projects. All such undertakings typically have benefits that are difficult to ue t r have been accident estimate, high costs and, most important, a strong political constituency. y t a Similar tales are told outside of government regarding pet projects for represent m are

l corporations, universities, and other bureaucracies. All such institutions can a fund large pie-in-the-sky projects with little "bottom-line" justification. It would errors be difficult to explain either the Empire State Building or the Sears Tower on

age breaks the basis of real estate market analyses. All these real-world political decisions P is new digit

h shape the character and scope of engineering practice, and often direct it away pographic y iles. T t

f from ecological sustainability. e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Perhaps then, the ''prepolitical'' state of their engineering training explains ibut f r t cannot the interest of the engineering students in my environmental politics classes. r at not

o These young people who are attracted to engineering haven't yet learned the f conventional levels of analysis, the appropriate and inappropriate systems to

however, analyze. The questions they ask have not yet been delimited by the political version ng,

t forces that define standard engineering practice. Indeed, the reason, arguably, paper book, at ive that I find the interests in ecology in my engineering students is precisely that at rm o they have a naive or, dare I say, pure attraction for the elegance and complexity riginal horit ic f

o of ecological systems. Their interest in design and models, which underpins e h their pursuit of engineering, easily translates into an appreciation of ecosystems. t he aut t

om In a sense this argues that despite engineers' "captivity," there is an r as ing-specif t essential element of engineering and the engineering approach that is very ion ed f likely shared by engineers long before their capture by social or professional or peset y economic forces. It is something more primal—maybe a problem-solving publicat

her t mentality, perhaps an instinct to make things work, or an urge to build something iles creat is h

t —that distinguishes the interest of the engineers (and presumably makes them L f

M of

and ot likely candidates for captivity) and is the element evinced by those students in X my environmental politics class. om yles, r f st version TOWARD A SYNTHESIS print posed e h heading Investigating the sources of their differences, then, reveals the underlying recom

use t affinities between engineers and ecologists and suggests a potential for fruitful communication and synthesis. Such a synthesis would require not so much a breaks, ease l been

P change in technical methods or training, but rather what I have called a political

word

has change. One obvious possibility is a redefinition of the scope of engineering ed.

hs, practice, with an emphasis on expansion of system boundaries to extend to the

insert impacts on natural systems on both input and output sides. As indicated, this is

ally necessarily a political undertaking, one which, while not partisan in the line lengt traditional sense, does require some managerial or leadership effort to redefine original work e h

t engineering practice. While in one sense this might seem threatening to standard engineering he original;

ion of practice, it would be a fundamental misunderstanding of the argument to t at o perceive such change as problematic for engineering. Engineering in essence, ue t r have been accident with its intuitive problem-solving and system orientation, might need to change y t a very little. Engineering as practice, for whom and for what, might have to represent m are

l change a great deal and adopt an additional set of constraints. a Recent efforts to bring ecology and engineering closer together have taken errors many forms ranging from industrial ecology (Frosch, 1993) to ecological

age breaks engineering (Mitsch, 1993). While all these initiatives reflect the spirit of the P is new digit

h argument presented here, they tend to fall short of what might be the ideal long- pographic y iles. T t

f run perspective. If the ecology of natural systems identifies significant earthly e ile: ng i f limits in terms of which sustainability must be expressed, then the devotion of a t F

D branch P peset and som is y h t

ined, a bout A ret original t

ion. om

r of engineering to this area of research and development represents another ibut f r t cannot boundary that limits the potential integration of the disciplines. The systematic r at not

o understanding of ecosystems can hardly be a branch of engineering independent f of, and parallel to, other engineering fields. Rather, it would seem that all

however, engineering fields should redefine their disciplinary specializations in terms of version ng,

t their respective systems' places in ecosystems. Rather than a new subfield or paper book, at ive discipline destined to take its place alongside existing specialties, the ecological at rm o model really is better understood as informing all subfields. It is this same riginal horit ic f

o ubiquity or inescapability that, I think, catches the attention of engineering e h students. The impact of ecology looks more like the constraints of t he aut t thermodynamics than like the opportunity for a new branch of the profession. om r as ing-specif t If we accept the need to face ecological constraints, the fundamental ion ed f recognition must be that the economy and the industrial system exist within and peset y depend on the ecosystem. Accordingly, twenty-first-century engineering and publicat

her t development must challenge industrial gigantism and expanding control and iles creat is h t

L f scale with a commitment to reengineer the developed world to have less impact

M of

and ot on ecosystems. X In practical terms, engineering within ecological constraints means turning om yles, r f engineering away from natural systems and back onto previously engineered st version systems. Two easy suggestions would be to follow Amory Lovins's print posed

e recommendation to "wring more efficiency" out of existing technologies and h heading Herman Daly's recommendation to substitute development for growth. recom

use t Finally, a metaphor might serve better than a list of recommendations. The treatment of wildlife by civilized societies has seen two conflicting models, the breaks, ease l been

P zoo and the wildlife refuge. In the former, wild natural creatures are brought

word

has into civilized, developed settings; in the latter, wild areas are set aside to be ed.

hs, protected and undeveloped, and civilization makes small unobtrusive outposts

insert that (at least in theory) do not upset the ecosystem that supports the wild area.

ally The lesson for future engineering is obvious. Wild creatures don't survive in line lengt zoos. The zoo model must be displaced by the wildlife refuge. In place of original work e h

t specimens from the wild transplanted into our engineered world (which we don't do well), we need to reengineer our artificial world and tidily insert it into he original;

ion of an otherwise protected and undisturbed global ecosystem. t at o ue t r have been accident y t NOTES a represent m are

a 1. From "The New Age," an address delivered at the Perkin Medal Meeting, Society of errors

Chemical Industry, Chemists' Club, New York, January 24, 1913, by Rossiter W. Raymond, quoting "a statement uttered by me ten years ago, in an address on the Dynamics and Ethics of

age breaks Engineering. It is so delightful to be able to reiterate without change an opinion ten years old." P is new digit [That is the reason for the quotation marks in the text above—quoting himself.] In The Journal h pographic

y of Industrial and Engineering Chemistry, March 1913, pp. 249-251. iles. T t

f e

ile: 2. One obvious exception might be the view of natural systems as "unproductive," which ng i f t

F generated a kind of restless urge to improve them, whether by irrigating arid lands or draining

D wetlands. P peset and som is y h t

ined, a bout A ret original t

ion.

om This perspective assumed that river, grassland, and forest ecosystems didn't do anything, that r ibut f r

t they were wasted or unproductive resources. John Wesley Powell's account of his journey cannot through the American West portrayed the land as potentially useful through reclamation. r at not o

f In contrast, a current concern of ecologists is with the productivity of unengineered or natural systems, and especially with unrecognized productivity.

however, 3. Goldman offers a series of contrasts between the two disciplines: version ng,

i t paper book, at ive ... the distinctive world outlook of engineering,... its theoria,... would be to the theoria of the at rm physical sciences as induction is to deduction, as the pragmatic is to the rational, as o riginal

horit nondeterministic design is to deterministic law, as the contextual is to the universal, as the ic f

o pluralistic and contingent is to the unique and necessary, as the open- ended is to the once-and- e h for-all, as Ciceronian rhetoric is to Platonic philosophy, as the skeptical is to the certain, as the t he aut t Principle of Insufficient Reason is to the Principle of Sufficient Reason (1990, p. 135). om r as ing-specif t ion

ed f 4. While most students find the material from a course on such issues to be obviously timely

peset and relevant to current events, the dedication exhibited by the engineering students seems to y reveal a special affinity between the interest they have in engineering and the logic or character publicat

her t of ecological science. iles creat is

h Though my impressions are just that, impressions, and not based on a systematic review, I feel t L f

M that this same enthusiasm and interest on the part of engineering students is much less of

and ot

X pronounced in the other political science classes I teach. om

yles, 5. Both fields, arguably, also seek a kind of internal elegance in the processes they investigate. r f st version 6. See James Karr's discussion of ecosystem "integrity" and "health" (in this volume), and C. S. Holling's investigation of ecological ''resilience'' (in this volume). Eugene P. Odum has argued print posed that the "holism" of ecology distinguishes it from the "reductionism" of analytic science and e h

heading should be a model for broader syntheses of the natural and social sciences (1977).

recom 7. If monetary constraints are the only costs considered, the only design parameters, then use t engineering, which might be good in terms of the specified constraints, could mean potential

breaks, disaster for the broader ecosystem. Illustrations of "well-engineered" products like lead paint, ease l been

P chlorofluorocarbons, and 8-mile-per-gallon cars indicate the nature of the problem.

word

has A similar point put in a slightly different way, as I suggest to the engineers in my classes, is that ed.

hs, designing a better car for an insane traffic system is not necessarily a design for an improved transportation system. insert 8. This scale issue is especially critical in a world that regards bigger as better. See Bryan ally Norton's argument that all environmental problems are essentially problems of scale (in this line lengt

original work volume). e h

t Daly and Cobb recommend sustainability quotas for resources, both sources and sinks, to

regulate the scale of the industrial economy. he original; ion of t

at Instead of beginning with the impossible task of calculating full-cost prices [prices including o externalities] and then letting the market determine the right quantities on the basis of these ue t r have been accident prices, we could begin with the 'right' quantities and let the market calculate the corresponding y t a prices. But what do we mean by the 'right' quantities? Only that the economy is constrained to represent m are

l operate with volumes of resource flows that are within the renewable biospheric capacities of a regeneration and waste absorption (1989, p. 142-143). errors

age breaks REFERENCES P is new digit h pographic Boulding, K. E. 1993. The economics of the coming spaceship earth. Pp. 297-309 in Valuing the y iles. T t

f Earth: Economics, Ecology Ethics, H. E. Daly and K. N. Townsend, eds. Cambridge, e ile: ng i f Mass.: MIT Press. t F Daly, H. E., and J. B. Cobb, Jr. 1989. For the Common Good: Redirecting the Economy Toward D Community, the Environment and a Sustainable Future. Boston, Mass.: Beacon Press. P peset and som is y Frosch, R. A. 1993. An approach to scenarios of the future industrial ecology. Paper presented at a h t

Conference on Technological Trajectories and the Human Environment. The Rockefeller

ined, University, New York City, October 28-29, 1993. a bout A ret original t

ion.

om Georgescu-Roegen, N. 1993. The entropy law and the economic problem. Pp. 75-88 in Valuing the r ibut f r Earth: Economics, Ecology Ethics, H. E. Daly and K. N. Townsend, eds. Cambridge, t cannot Mass.: MIT Press. r at not

o Goldman, S. L. 1990. Philosophy, engineering and Western culture. Pp. 125-152 in Broad and f Narrow Interpretations of Philosophy of Technology, P. T. Durbin, ed., Philosophy and Technology, Vol. 7. Dordrecht, Netherlands: Kluwer Academic Publishers. however, Goldman, S. L. 1991. The social captivity of engineering. Pp. 121-145 in Critical Perspectives on version ng,

t Nonacademic Science and Engineering, P. T. Durbin, ed., Research in Technology paper book, at ive Studies, Vol. 4. Bethlehem, Pa.: Lehigh University Press. at rm Lovins, A. B., L. H. Lovins, and S. Zuckerman. 1986. Energy Unbound: A Fable for America's o

riginal Future. San Francisco, Calif.: Sierra Club. horit ic f

o Meadows, D. H., D. L. Meadows, and J. Randers. 1992. Beyond the Limits: Confronting Global e

h Collapse ; Envisioning a Sustainable Future. Post Mills, Vt.: Chelsea Green. t he aut t

Mitsch, W.J. 1993. Ecological engineering: A cooperative role with the planetary life-support om r

as system. Environmental Science and Technology 27:438-445. ing-specif t Odum, E. P. 1977. The emergence of ecology as a new integrative discipline. Science ion ed f 195:1289-1293. peset

y Schattschneider, E. E. 1975. The Semisovereign People: A Realist's View of Democracy in America. New York: Dryden. publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not CASE STUDIES o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ENGINEERING FOR DEVELOPMENT IN ENVIRONMENTALLY SENSITIVE AREAS: 141 OIL OPERATIONS IN A RAIN FOREST e h t be

ion. om r ibut f r t cannot r at not Engineering for Development in o f Environmentally Sensitive Areas: Oil however, version ng,

i Operations in a Rain Forest t paper book, at ive at rm o riginal horit ic f o e

h June Lindstedt-Siva, Lou C. Soileau IV, t he aut t

Dilworth W. Chamberlain, and Martin L. Wouch om r as ing-specif t ion ed f

peset THE DILEMMA OF DEVELOPMENT IN NATURAL HABITATS y

publicat Human populations and their support systems have expanded to the point her t iles creat is

h that they can potentially affect global ecology. Perhaps the most significant t L f

M of impacts are the long-term ecological effects that result from anthropogenic

and ot X disturbance, modification, and conversion of natural habitats. The result is that om yles, r

f native plant and animal populations are reduced, confined to small areas, or lost st version altogether. At some point the survival of species themselves may be in

print jeopardy. Most species become endangered or threatened not for genetic or posed e h

heading physiological reasons, but because their habitat is modified or eliminated, or

recom they are overharvested. use t Rapid human population increases are occurring in less developed, tropical breaks, ease l been countries where biological diversity is greatest. Here, deforestation is resulting P in the rapid loss of rain forest habitat, potentially eliminating species about word has ed.

hs, which little is known. Pressure on natural systems comes from basic survival needs for food and fuel and from the desire of the people and their governments insert to raise the country's standard of living, provide housing, and promote ally

line lengt industrialization and modem agricultural development. The problem is not original work

e confined to the developing world; industrialized countries are also losing h t natural habitats. There is little hope of stopping natural habitat losses in the near term. This he original; ion of t at o is as true in the Santa Monica Mountains of southern California as in the forests

ue t of Brazil. Some important habitats can be protected in parks or reserves, but this r have been accident y t

a strategy saves only habitat "islands" and, alone, cannot ensure maintenance of represent m are

biodiversity over time. Solutions for the long-term must emphasize finding ways l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r to maintain the ecological integrity and functions of "developed" areas. This ibut f r t cannot approach is consistent with the concept of sustainable development (Lovejoy, r at not

o 1994). f however,

version DEVELOPMENT THAT PRESERVES ECOLOGICAL ng,

i t paper book, at ive INTEGRITY at rm o The following are examples of development that has resulted in riginal horit ic f

o preservation of ecological or biological integrity as defined by Angermeier and e h Karr (1994). In each of these examples, most of the land is maintained in open t he aut t

om space, and "facilities" occupy only a small portion. In addition, public access is r as ing-specif t restricted. ion ed f Camp Pendleton Marine Base in San Diego County, California, contains peset y many small wetlands that would have been converted to marinas and publicat

her t condominiums long ago had they not been on the military base. Because so iles creat is h t

L f many acres of wetlands have been lost to development in southern California,

M of

and ot the small remaining wetlands at Camp Pendleton are increasingly important to X coastal ecology. om yles, r f Point Mugu Naval Air Station in Ventura County, California, also supports st version many acres of wetlands, and some endangered species. In addition, because it is print posed

e protected from disturbance, this is one of the few parts of the southern h heading California mainland coast where seals and sea lions regularly haul out to rest. recom

use t Vandenberg Air Force Base in Santa Barbara County has some of the best rocky intertidal habitat in California, supporting the biodiversity that was lost breaks, ease l been

P from more populated areas of the coast many years ago.

word

has The Guadalupe Dunes oil field in Santa Barbara County consists of oil ed.

hs, wells, pipelines, roads, and oil storage and treatment facilities. Because most of

insert this coastal property is maintained in open space and public access is restricted,

ally it is one of the last places in the region where native dune vegetation survives, line lengt including some endangered species. Because of public use (dune buggies, dirt original work e h

t bikes), dunes adjacent to the oil field are damaged so that they no longer support native vegetation. he original;

ion of Similarly, in Kern County, California, oil fields are some of the only t at o remaining large tracts of land that have not been converted to agriculture or ue t r have been accident urbanization. Here, too, native plants and animals are present, including several y t a endangered species. One working oil field was recently designated an represent m are

l ecological preserve and is being managed as such, in cooperation with state a agencies. This management will continue beyond the life of the oil field (Loll errors and Steinhauer, 1993).

age breaks For these examples, protection of natural ecosystems was often an P is new digit

h unforeseen by-product of the type of development that occurred. However, pographic y iles. T t

f today these environments are protected by design, as part of managing the e ile: ng i f facilities. It is the latter, environmental protection by design, that must be t F

D encouraged and supported both domestically and internationally. P peset and som is y h t

ined, a bout A ret original t

ion. om

r ENVIRONMENTAL PLANNING AND MANAGEMENT ibut f r t cannot PROCESS r at not o

f The goals of environmental planning and management are to minimize the adverse environmental impacts of development and to maintain or enhance the however,

version ecological integrity and functions of the natural system. The principles can be ng,

i t paper book, at ive applied to development as diverse as an agricultural crop, housing tract, power at rm plant, or oil production. The interdisciplinary process of environmental o riginal horit

ic f planning and management requires interaction of the environmental sciences, o

e engineering, and operations. It can be applied to ongoing operations or new h t he aut

t projects, though it has its greatest effect when applied to new projects early in

om r as ing-specif their development, when siting, design, and engineering options are still open. t ion

ed f Figure 1 illustrates the process. The process begins when a project peset

y proposal is developed, including siting and design alternatives. An environmental reconnaissance study is conducted to identify the major publicat her t iles creat is ecological features of each site. h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks FIGURE 1 Environmental planning and management process. P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r This need not be, and in most cases cannot be, a lengthy and expensive ibut f r t cannot study. Much can be learned by knowledgeable scientists from a literature r at not

o review, site visit, and study of topographic maps and aerial or satellite photos. f On the basis of this information, an environmental impact assessment is

however, prepared. This includes an analysis of the potential impacts of the various version ng,

t alternatives as well as recommendations of alternatives and mitigation paper book, at ive measures. This information is fed back into an environmental management plan at rm o for the project siting and design process. The site and project design alternatives riginal horit ic f

o are selected and permits and other approvals are obtained. e h During the construction phase of the project, environmental monitoring t he aut t

om begins. Monitoring may begin before construction if additional, site-specific r as ing-specif t environmental data are needed. Monitoring to establish a baseline against which ion ed f to measure future impacts is usually not feasible because of the time, scope, and peset y cost of a study required to define natural variation. Therefore, the monitoring publicat

her t program must focus on environmental parameters and populations likely to be iles creat is h

t affected during the construction and operations phases of the project. L f

M of

and ot Environmental impacts are assessed and the information is fed back into an X environmental management plan that becomes part of the operations plan for om yles, r f the project. Monitoring continues to some degree during operations so that st version impacts can be assessed continually and the management and operations plan print posed

e can be modified as necessary. h heading Once this process is completed, the environmental and engineering recom

use t information generated becomes extremely valuable to those planning similar developments or different projects in similar habitats. Therefore, dissemination breaks, ease l been

P of the results—including both successes and failures—is critical.

word has ed. hs, OIL DEVELOPMENT IN AN ECUADOR RAIN FOREST insert

ally Tropical forests are complex environments that support a greater diversity line lengt of plant and animal species than any other terrestrial habitat. Most of these original work e h

t species (e.g., insects) have not been named, described, or studied by scientists. Raven (1994) estimates that there are 8-10 million species on earth, though only he original;

ion of 1.4 million have been named. Tropical forests are also rich in substances, both t at o medicinal and industrial, that are useful to their indigenous residents as well as ue t r have been accident society at large (Lewis, 1990). y t a Tropical rain forests receive 80-300 inches of rainfall a year (Holdridge, represent m are

l 1967). They typically consist of a relatively tight canopy of broad-leafed a evergreen trees and two or more underlying layers of trees and shrubs. errors Undergrowth vegetation is usually sparse because little sunlight reaches the

age breaks forest floor. Soils are typically acidic and poor in nutrients. Nutrient cycling P is new digit

h depends on degradation of leaf litter, fallen trees, and shrubs on the forest floor. pographic y iles. T t

Because this cycle is so easily altered by disturbance, tropical forests are among f e ile: ng i f the world's most sensitive environments (Wilson, 1988). The largest remaining t F

D contiguous tracts P peset and som is y h t

ined, a bout A ret original t

ion. om

r of tropical forests are in the Amazon drainage of South America and in central ibut f r t cannot Africa. r at not

o The scientific community has recognized the problem of deforestation in f the tropics for a long time. In 1980 a National Research Council panel predicted

however, that most forests would not exist as they were at that time by the close of the version ng,

t century (National Research Council, 1980). Deforestation in the tropics is also paper book, at ive thought to influence local climate and contribute toward global climate change at rm o (Wilson, 1988). The ecology of humid tropical systems is poorly understood. riginal horit ic f

o Substantial research is needed to develop sustainable uses in these systems as e h well as methods to reduce impacts of development and restore damaged t he aut t systems (National Research Council, 1982; National Science Board, 1989). om r as ing-specif t The environmental impacts of development in the tropics are closely ion ed f linked to socioeconomic effects. Bringing development of any kind to semi- peset y isolated indigenous populations generally brings profound changes to those publicat

her t cultures. Contact alone may expose communities to diseases for which no iles creat is h t

L f immunity has been developed. Alteration of the natural habitat may deplete or

M of

and ot alter traditional food and water sources. When two cultures come into contact, X the dominant culture will, in the long run, submerge the other culture unless om yles, r f preventive steps are taken. st version print posed e

h Major Environmental and Social Issues heading recom

use t Deforestation and habitat alteration are occurring rapidly in the tropics worldwide. Historically, the primary cause of deforestation in South America breaks, ease l been

P has been invasion by colonists who clear the forest to raise cattle or grow crops.

word

has Governments have also "opened" new areas, encouraging colonization and ed.

hs, other types of development. Roads are probably the major contributing factor in

insert deforestation. Wherever roads have been built into previously isolated areas, the

ally result has been encroachment by "outsiders," followed by deforestation and line lengt environmental degradation as well as profound social impacts. Oil development original work e h

t in the tropics has often also included major road construction. Compared with deforestation and habitat loss, environmental pollution he original;

ion of from oil operations using contemporary technologies and practices is a lesser, t at o though potentially significant issue in the tropics. When vegetation is removed ue t r have been accident and heavy equipment used, there is a high potential for soil erosion and y t a contamination of streams used for drinking water as well as fishing. Garbage represent m are

l and sanitation wastes as well as oil exploration and production wastes are a potentially significant sources of contamination in these sensitive environments. errors Air pollution associated with operations may be locally significant.

age breaks In the past, when areas of tropical forest were "developed," the results P is new digit

h were often also detrimental to indigenous people. Uncontrolled, spontaneous pographic y iles. T t

f colonization by outsiders often displaced the local populations and introduced e ile: ng i f diseases. Colonists in all parts of the world have been tenacious and relentless. t F

D Stopping or P peset and som is y h t

ined, a bout A ret original t

ion. om

r slowing colonization is extremely difficult, especially when there are roads into ibut f r t cannot an area and when colonization is an attractive option for improving the lives of r at not

o settlers. Social consequences may include displacement of indigenous people f and degradation or depletion of resources needed for survival (drinking water

however, and native plants and animals), erosion of culture, alcoholism and other ills, and version ng,

t the possibility of making communities dependent on the outside world with no paper book, at ive way to maintain or return to traditional ways if outside support systems are at rm o removed. riginal horit ic f o e h t he aut

t ARCO Project

om r as ing-specif t It is in this context that ARCO Oriente Inc. (a subsidiary of Atlantic ion ed f Richfield Company [ARCO] based in Quito) is exploring for oil in Ecuador. peset y ARCO International Oil and Gas Company (AIOGC), a division of ARCO, has publicat

her t oversight responsibility for ARCO Oriente. The site is Block 10, a forested area iles creat is h t

L f on the eastern slopes of the Andes and part of the Amazon drainage basin

M of

and ot (Figure 2). The remainder of this paper describes the major environmental and X social issues relevant to the project (Lindstedt-Siva and Chamberlain, 1991), om yles, r f and discusses some of the ARCO programs in place during the exploration st version phase, as well as plans for the development phase of the project. These plans print posed

e will be finalized and implemented if ARCO and the government of Ecuador h heading agree to proceed with the development project. The following discussion recom

use t outlines an approach to oil development that, in many respects, represents a major departure from conventional operations and, in our view, a significant breaks, ease l been

P advance in environmental protection.

word has ed. hs, Exploration Phase insert

ally Oil exploration and production in Ecuador began early in the 1900s, first line lengt along the Pacific coast and later in the interior. ARCO Oriente Inc. began original work e h

t exploring for petroleum in Ecuador in November 1988. ARCO and its partner, AGIP (Overseas) Ltd., are service contractors for the Ecuador state petroleum he original;

ion of company, PETROECUADOR, by an agreement signed in June 1988. Block 10 t at o covers 200,000 hectares (494,000 acres) in Pastaza Province. ue t r have been accident PETROECUADOR and other oil companies produce approximately 390,000 y t a barrels of oil a day from fields north of Block 10. represent m are

l Between November 1988 and July 1989, seismic exploration was a conducted throughout the block (Figure 3) except in the extreme southwest errors corner, where operations were discontinued in deference to the wishes of

age breaks indigenous people living in the area. Seismic lines (narrow paths to aid P is new digit

h deployment of seismic exploration equipment) as well as footpaths and helipads pographic y iles. T t

f needed to support the seismic operations were cleared by hand (chain saw and e ile: ng i f machete) and occupied an estimated 341 acres. A subsequent seismic operation t F

D conducted between August 26 and September 29, 1991, resulted in hand- P peset and som is clearing an additional 14.4 acres. y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert

ally FIGURE 2 ARCO International Oil and Gas Co., ARCO Oriente, Block 10, line lengt

original work Pastaza Province, Ecuador. e h t

Three exploratory oil wells were drilled at two roughly 4.5-acre sites, he original; ion of

t Moretecocha and Villano, named for nearby villages and chosen with assistance at o from the villagers. One well was drilled near Moretecocha and two near ue t r have been accident y

t Villano. Oil has been found at both locations, but the Villano wells appear to a have standalone commercial potential. Possible pipeline routes have been represent m are

a surveyed from the Villano discovery area. errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading FIGURE 3 Seismic operations and exploratory well sites, Block 10. recom use t breaks, ease l been

P Environmental and Social Strategies

word has ed. A major goal of the company is to minimize adverse environmental and hs, social effects of the project. Environmental guidelines for rain forest insert exploration operations were developed by ARCO before drilling the first ally

line lengt exploratory well (AIOGC, 1990). Major elements include the following: original work e

h 1. Build no new roads—move all equipment and personnel using existing t out-of-forest roads, aircraft, or on foot.

he original; 2. Minimize the ''footprint'' of all operations (seismic lines, helipads, ion of t at o campsites, drill sites)—the smallest feasible footprint minimizes

ue t vegetation removal and reduces all other environmental impacts r have been accident y t

a accordingly. represent m are

l 3. Minimize the use of heavy equipment (tractors)—use hand methods a (machete, chain saw) when vegetation must be removed. Natural errors restoration of disturbed areas is much faster if the topsoil is not disturbed. 4. Consult with local communities—informing and involving residents of age breaks P is new digit villages nearest to, and most affected by, the project is vital. For example, h pographic y iles. T

t local

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r villagers help select trees to be used in construction, participate in cutting ibut f r t cannot lumber, and advise ARCO on other environmental and social issues, such r at not

o as identification of wildlife and plant species, and on the locations of f cultural significance to villages. Although primary emphasis has been at

however, the "grass roots," it is also important to encourage dialogue with all version ng,

t indigenous groups that express an interest in such dialogue. paper book, at ive 5. Restore disturbed sites. at rm o riginal horit ic f o

e Lumber Harvesting and Transport h t he aut t

om Drill sites were designed to be smaller (4.5 acres) than those commonly r as ing-specif t constructed in the area (about 12 acres). Some lumber was required for ion ed f construction at drill sites and campsites. Indigenous residents, in cooperation peset y with Ecuadorian foresters, selected trees for harvest on the basis that they were publicat

her t fast-growing and not used to make canoes or otherwise significant to the iles creat is h

t community (e.g., special use or meaning). Trees were cut by hand using chain L f

M of

and ot saws at remote locations, taking care to minimize canopy gaps. Boards were cut X at the remote site, then transported to the construction site by helicopter or om yles, r f footpath. This method of harvesting and transporting lumber is unconventional st version and greatly reduced the ecological impacts of the project over what it would print posed

e have been expected if lumber were harvested and transported through the forest h heading in the conventional way using heavy equipment (McMeekin, 1991; McMeekin recom

use t and Zak, 1990). This method of selective harvesting closely mimics natural treefall in that breaks, ease l been

P only single trees are cut in a given area; there is no "clearing." Gaps in the

word

has canopy due to natural treefall create light gaps of up to 360 square meters. Light ed.

hs, can penetrate to ground level in these gaps, creating microhabitats and

insert stimulating plant growth (Brokaw, 1982; Connell, 1979). For ARCO

ally operations, trees were selected and harvested at unevenly spaced intervals, line lengt depending on the location of trees meeting the selection criteria. After six original work e h

t months, gaps created from timber harvesting displayed vegetation regeneration similar in genetic diversity and structure to that found in natural treefall gaps, he original;

ion of although trampling and a thick layer of sawdust slowed recovery of some areas t at o (Woodward-Clyde, 1992). Recovery in exposed areas begins with the growth of ue t r have been accident sun-tolerant species as the first stage of the succession process that leads to y t a natural restoration of the forest (Brown and Press, 1992). represent m are

l a errors Construction and Heavy Equipment

age breaks Construction of drill sites for exploratory wells was the only part of the P is new digit

h project that required the use of heavy equipment in remote areas. The drilling pographic y iles. T t

f rig and supporting heavy equipment were brought to the site in sections by e ile: ng i f helicopter and assembled at the site. Heavy equipment use was permitted only t F

D within the P peset and som is y h t

ined, a bout A ret original t

ion. om

r confines of the drill site. After construction and drilling were completed, all ibut f r t cannot equipment was disassembled and removed by helicopter. r at not o f Reclamation however, version ng,

t Natural recovery of helipads, seismic lines, and campsites was rapid paper book, at ive because vegetation was cut by hand (using chain saws and machetes) and top at rm o soil was not disturbed. Where heavy equipment was used to construct drill sites, riginal horit ic f

o recovery has taken more time. Reclamation programs were implemented to e h enhance the recovery process. Topsoil removed to construct drill sites was t he aut t

om retained and protected on-site. Nurseries were established at each drill site to r as ing-specif t provide native plant seedlings. Monitoring of the initial phase of reclamation at ion ed f the Moretecocha-1 well site indicated that additional work was appropriate; this peset y work has been recently completed. A reclamation program incorporating what publicat

her t was learned at Moretecocha was implemented at the site where the Villano-2 iles creat is h

t and Villano-3 wells were drilled. This site was occupied for about two and one- L f

M of

and ot half years and may be used in the future if the oil discovery is developed. The X plans for both the Moretecocha (most recent phase) and Villano sites included om yles, r f contractual terms for local indigenous monitoring and maintenance to tend the st version vegetation and replace any plants failing to survive, as well as to report print posed

e problems at the sites requiring attention from ARCO. h heading recom use t Social Issues breaks, ease l been

P The situation with regard to indigenous communities in Ecuador is

word

has complex. There are three major groups living in Block 10—Quichua, Huaorani, ed.

hs, and Schuar. These indigenous groups, the colonists, provincial leaders, and the

insert Ecuadorian government are involved in an ongoing controversy over land fights

ally and development issues. However, Ecuador has made progress in resolving land line lengt fights issues by granting such fights to various communities in 1992. Several original work e h

t organizations claim to represent the various indigenous communities, and it has been a challenge for ARCO to cooperate with any one organization without he original;

ion of alienating another. In attempting to minimize such controversy and keep the t at o consultation and decision making close to the communities that are nearest to, ue t r have been accident and likely to be most affected by, oil operations, ARCO has focused more y t a attention on communities than on the larger, representative organizations. represent m are

l ARCO Oriente personnel meet regularly with communities to maintain a communication, exchange information, and resolve issues. ARCO Oriente has errors developed partnerships with communities in the vicinity of operations by

age breaks negotiating agreements with them for the use of their land, rather than merely P is new digit

h assuming the fight to use the land according to agreements with the Ecuadorian pographic y iles. T t

government. As a result of consultation and negotiation, ARCO has provided f e ile: ng i f support to the communities in the form of medical assistance, training, t F

D educational supplies, school structures, and airship P peset and som is y h t

ined, a bout A ret original t

ion. om

r improvements. The goal of this support is that it result in positive changes in the ibut f r t cannot community that will last beyond the life of the project. r at not o f Development Phase however, version ng,

t As of this writing, ARCO and AGIP are preparing a field development paper book, at ive plan that the government of Ecuador will use to decide whether or not the at rm o project should proceed to the development phase. In anticipation of riginal horit ic f

o development, a number of environmental studies and planning exercises were e h completed. Whether or not the project proceeds, the ideas and strategies that t he aut t

om emerged from this process have broken new ground and provided what may be r as ing-specif t a model for development in environmentally sensitive areas. ion ed f peset y Conventional Technology and Approaches publicat her t iles creat is h t

L f Conventional development of an oil field requires construction of drill

M of

and ot sites, pipelines, gathering and processing facilities, and pump stations. X Technology and construction methods for these facilities are well established om yles, r f and accepted in the industry and are currently common practice in Ecuador and st version elsewhere. Drill sites in this region have historically occupied about 12 acres. print posed

e They are connected to one another and to support facilities by roads. Pipelines h heading are used to transport oil from wells to gathering and treatment facilities and for recom

use t shipment out of the area. Pipeline construction requires road construction first, so that equipment can be moved to the site. Roads are also required for access breaks, ease l been

P to the oil fields and pipeline for routine operations. Pipelines are typically

word

has monitored from aircraft, requiring that pipeline corridors be cleared of ed.

hs, vegetation so that leaks or other problems can be detected from the air.

insert In addition, remote operations complicate the problem of transporting

ally workers to and from the oil fields. Normally, workers are housed in the field for line lengt shifts of 7 to 14 days. Oil field operations continue 24 hours a day; therefore, a original work e h

t contingent of 40 to 50 personnel is not unusual.

he original; ion of t at

o Environmentally Based Technology ue t r have been accident During planning, all conventional approaches to drilling, operations, and y t a logistics were challenged. Can alternative approaches be developed that will represent m are

l reduce environmental and social impacts of the project over conventional a approaches? Is it possible to develop an oil field in a remote forest without errors roads? Can alternative methods be found to construct and monitor a pipeline

age breaks without roads and without breaking the forest canopy? P is new digit

h When we first asked these questions, the nearly universal response was pographic y iles. T t

f that it is not possible to develop a project without roads. At a minimum, an e ile: ng i f unconventional, roadless project was expected to be costly. The more the t F

D questions were P peset and som is y h t

ined, a bout A ret original t

ion. om

r studied, however, the more likely it looked that at least some of the challenges ibut f r t cannot could be met. The following concepts emerged from these studies. r at not o f The Offshore Model however, version ng,

t The goals of a roadless operation with a small footprint caused the project paper book, at ive team to search for an alternative model to conventional oil field development at rm o technology. The key breakthrough in our thinking came when the project leader riginal horit ic f

o (L. C. Soileau) visualized oil production in a rain forest using the only current e h example of oil production without roads, an offshore operation (Figure 4a). The t he aut t

om setting of a remote, tropical rain forest is directly analogous to an offshore site. r as ing-specif t If the offshore model is applied to this onshore situation, many of the same ion ed f practices and development techniques used by ARCO in open waters could be peset y applied cost-effectively to the rain forest environment. ARCO had already publicat

her t gained experience developing small-footprint operations as part of the large oil iles creat is h

t production project on the North Slope of Alaska. The goal there was to L f

M of

and ot minimize impacts on tundra. X om yles, r f st version Refining the Offshore Model print posed

e Conventional contemporary onshore development with a road was h heading evaluated to give baselines for development and construction time, cost, and recom

use t risk as well as the socioenvironmental impacts. This approach was evaluated against conventional offshore development as well as variations of the offshore breaks, ease l been

P model.

word

has The conventional offshore approach is to house personnel on platforms, ed.

hs, along with processing facilities for oil, gas, and water. Logistical support for the

insert platforms (e.g., crew and equipment transport) is provided by boat or helicopter.

ally The rain forest version of this approach would be to locate processing facilities line lengt and personnel quarters in a compact design at the drill site with logistical original work e h

t support by air. The second alternative evaluated is production processing in the field he original;

ion of while housing personnel at the nearest community with support facilities (water, t at o electricity, housing, roads). This hybrid concept allows for location of oil, gas, ue t r have been accident and water processing at the oil field as in a conventional development combined y t a with the offshore approach to logistics and support. represent m are

l A third alternative, locating processing facilities as well as worker housing a at the nearest urban community along the oil pipeline route, is the current errors preferred model (Figure 4b). Here there is access to electric power, roads to

age breaks other areas, and existing support systems for oil field workers, including P is new digit

h housing and telecommunications. The equipment and systems at the oil field are pographic y iles. T t

f minimized and as simple, reliable, and durable as possible. This approach e ile: ng i f concentrates people at the population center and reduces the number of people t F

D required in the field. The P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t FIGURE 4 (a) Conventional offshore oil development. (b) Offshore development model applied to rain forest. he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r complication of this approach is the isolation of producing wells from field ibut f r t cannot supervisors and work crews. r at not o f Production Processing Technology however, version ng,

t Conventional contemporary oil field technology used to separate and treat paper book, at ive produced oil, gas, and water is complex, requiring close monitoring and at rm o maintenance (Figure 5a, conventional technology). Project engineers studied riginal horit ic f

o various alternatives and finally developed a simpler, low-maintenance approach e h (Figure 5b, alternative technology). This alternative minimizes the acreage t he aut t

om required for equipment as well as numbers of workers required to support it. r as ing-specif t This minimizes environmental impact and also reduces the opportunity for ion ed f social interaction between indigenous communities and oil workers. The lack of peset y road access gives protection from colonization by outsiders and maintains local publicat

her t control. The indigenous communities will continue to manage their lands and iles creat is h

t resources and can make the deliberate decision to discourage or encourage entry L f

M of

and ot of colonists, other industries, or agriculture. In addition, since company and X contractor personnel will visit the field only as needed, greater control of om yles, r f cultural "evolution" will be exercised by the indigenous people themselves. st version There are possibilities for long-term employment of local people, if desired. print posed

e Further, with flexibility designed into the pipeline, power, and processing h heading systems, future discoveries can be integrated into this plan with continued recom

use t minimal impact. breaks, ease l been P Costs word has ed.

hs, Costs for a remote operation are higher than costs for conventional

insert operations during the construction phase. However, the offshore model

ally approach will reduce costs over the long-term because of the smaller number of line lengt personnel that must be maintained at remote locations, the simplicity and lower original work e h

t maintenance required for production equipment, and the lack of road construction and maintenance. he original; ion of t at o Pipeline Options ue t r have been accident y t a Many pipeline options were evaluated. Only three constraints were placed represent m are

l on engineering teams: (1) the capability of transporting 30,000 barrels a day, (2) a no permanent roads leading to developed areas, and (3) a cleared right-of-way errors less than 20 feet wide, rather than the conventional 60 feet. Numerous

age breaks innovative techniques for constructing and monitoring the pipeline have P is new digit

h emerged. pographic y iles. T t

f One of the more unusual concepts was to design a land pipelay barge . e ile: ng i f Constructing a pipeline offshore requires a specially made barge that transports t F

D the pipe to the offshore location and contains equipment needed to weld, wrap, P peset and som is inspect, and lay the pipeline on the seafloor. The ARCO team thought that tree y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. http://www.nap.edu/catalog/4919.html Engineering WithinEcologicalConstraints About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication as the authoritative version for attribution. OIL OPERATIONS OIL OPERATIONS ARAIN IN FOREST SENSITIVE AREAS: DEVELOPMENTIN ENGINEERING ENVIRONMENTALLY FOR Copyright © National Academy ofSciences. Allrights reserved.

FIGURE 5 Conventional and alternative oil field technology. 155 Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ENGINEERING FOR DEVELOPMENT IN ENVIRONMENTALLY SENSITIVE AREAS: 156 OIL OPERATIONS IN A RAIN FOREST e h t be

ion. om

r removal could be minimized by designing a land barge of multiple, ibut f r t cannot wheeled platforms linked together. The right-of-way for the pipeline would be r at not

o slightly wider than the barge since each platform would straddle the pipeline f ditch. Each platform would serve a separate function. The lead unit would

however, trench the ditch. The second unit would carry the sections of pipe and feed them version ng,

t one by one into the automatic welding machine. The third unit would quench paper book, at ive and wrap the pipe. The fourth unit would inspect and drop the pipeline into the at rm o ditch. The fifth unit would refill the ditch. Using retired military-tracked heavy riginal horit ic f

o vehicles, this concept may yet be viable. e h Using manual labor to construct the pipeline would reduce the need for t he aut t

om heavy equipment and roads. This approach would require either laying the r as ing-specif t pipeline on the surface or digging the ditch by hand. A surface line would ion ed f minimize tree loss and corridor width. However, conventional 15- to 24-inch- peset y diameter pipe is difficult or impossible to move by hand. In addition, welding publicat

her t machines are required to connect the 40-foot sections. This problem could be iles creat is h

t solved by using high-pressure plastic pipe that could be fused together with L f

M of

and ot machines that can be carried by humans over rough terrain. Alternatively, two X smaller parallel pipelines could be installed rather than one larger one. The om yles, r f smaller pipe would be easier to handle in the field. st version Another approach is to use flexible, armored pipe such as is used offshore. print posed

e This pipe is reinforced, high-pressure rubber hose wrapped in a metal sheath. h heading Long sections of coiled pipe could be flown along the pipeline route, uncoiled recom

use t and connected by hand, and laid around the larger trees. Consideration was given to a double pipeline with oil flowing through the breaks, ease l been

P center pipe and monitoring equipment in the space between the small and large

word

has pipe. Such a double-walled pipe could be laid in the Villano River. Although ed.

hs, there would be temporary disruption to the river, this technique would minimize

insert vegetation removal and soil disturbance during pipeline construction as well as

ally the need for roads to transport equipment. line lengt To avoid constructing a permanent road along the pipeline, it may be original work e h

t possible to build temporary roads that would be dismantled after pipeline construction. Temporary roads could be surfaced with reusable materials, such he original;

ion of as surplus steel plating from military aircraft runways or "lumber" made from t at o recycled plastic waste. This material could be moved along the pipeline route ue t r have been accident and used as road surface for the heavy ditching and pipe-moving equipment. In y t a many places, temporary bridges could be used and then removed to eliminate represent m are

l permanent river crossings. a The terrain may require tunneling through small hills, under streams, or errors from the top to the bottom of escarpments. Sections of the pipeline could be laid

age breaks in these small-diameter tunnels to eliminate permanent bridges and impede the P is new digit

h crossing of any of these natural barriers by off-road vehicles or horse-drawn pographic y iles. T t

f carts. e ile: ng i f Using these concepts, it may be possible to design the pipeline so that the t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r right-of-way is 20 feet or less. With a corridor of this size, the natural forest ibut f r t cannot canopy may be preserved or easily restored. r at not o f Pipeline Monitoring and Maintenance however, version ng,

t Once the pipeline is laid, it must be monitored for breaks, corrosion, and paper book, at ive leaks. Normally, a pipeline route is observed by periodic overflights using a at rm o small airplane or a helicopter. If this pipeline is constructed using techniques riginal horit ic f

o that allow the forest canopy to remain unbroken, airborne observation will not e h be possible. Again using the offshore model, flow meters could be used to t he aut t

om monitor the volume of oil in the pipe at various points. Pressure monitors can be r as ing-specif t used to detect leaks. As is the case in all major pipelines, instruments are placed ion ed f in the pipe to clear the line of extraneous fluids and monitor corrosion. To take peset y the place of aerial observation, indigenous people who live along the route publicat

her t could be hired to walk the line and report any leaks or damage. iles creat is h t L f

M of

and ot

X Selecting an Approach om yles, r f Some of these concepts may be viable and find their way into the project. st version Availability of materials such as superhigh-pressure plastic pipe or the print posed

e feasibility of "land barges" will be considerations. Cost will also be a major h heading consideration. Reinforced flexible pipe, for example, would be extremely recom

use t expensive and may not even be available in the large diameter required. However, exploring ideas such as these has enabled project personnel to breaks, ease l been

P completely rethink the process of constructing, maintaining, and monitoring a

word

has pipeline. ed. hs,

insert Current Status of Environmental Planning and Management ally

line lengt The type of environmental planning and management described here is not original work e h

t widely practiced, even in developed countries. Yet, if we hope to conserve natural ecosystems and reduce the rate of loss of biological diversity, sound he original;

ion of environmental planning and management are critical. The process need not be t at o lengthy or expensive. The key for the long-term is adequately trained ue t r have been accident environmental scientists, engineers, and operating personnel working together. y t a These teams must be challenged to "break the mold" and depart from represent m are

l conventional thinking. a errors

SCIENCE AND ENGINEERING NEEDS age breaks P is new digit

h Environmental planning and management is based on getting information pographic y iles. T t

f from the environment and feeding it back into the management plan of the e ile: ng i f project. We must find better, less expensive, and less time-consuming ways to t F

D obtain this information. We need scientifically sound, rapid assessment and P peset and som is monitoring y h t

ined, a bout A ret original t

ion. om

r methods that are affordable. Neither industries nor government regulatory ibut f r t cannot agencies have the resources to do long-term, baseline studies to inventory r at not

o species and document natural variation of populations. Yet, accurate f environmental data, useful in the project management process, are needed. For

however, most development projects around the world, in both developing and version ng,

t industrialized countries, resources will not be available to support the type of paper book, at ive environmental studies that have been required in North America and western at rm o Europe, and these fall short of a real baseline. More effective, less costly riginal horit ic f

o methods are needed everywhere. e h Since it will not be possible to study everything, we need to develop t he aut t

om methods that focus on those parameters that will tell us most about the r as ing-specif t environment at least cost. Are there different or better ways to make use of ion ed f satellite-generated data and aerial photography? Can some populations be used peset y as indicators of environmental quality to eliminate the need to monitor all publicat

her t populations (e.g., birds, ants, butterflies)? Are there some stages of the life iles creat is h

t cycle more appropriate to monitor than others (e.g., larvae)? What physical L f

M of

and ot parameters would yield the most appropriate information about the environment X in the least time at the least cost? Under the auspices of Conservation om yles, r f International, two biologists, Al Gentry and Ted Parker, developed the Rapid st version Assessment Program, which uses satellite imagery, aerial reconnaissance, and print posed

e field surveys to develop an inventory of species in just a few weeks (Roberts, h heading 1991). In addition, a panel of tropical scientists recommended that specific key recom

use t plant and animal populations be surveyed prior to development activities in the tropics (National Research Council, 1982). These are good examples of breaks, ease l been

P approaches to this problem.

word

has Durable, low-cost instrumentation is needed for environmental monitoring ed.

hs, from temperature probes to current meters to animal collars that use satellite

insert telemetry for tracking. The extent to which monitoring can be automated and

ally equipment made durable and easy to use will determine its applicability in line lengt project management. original work e h

t One way to reduce the loss of natural ecosystems is by restoring damaged systems, creating new systems, and enhancing existing systems. There have he original;

ion of been several projects to create or restore wetlands. Others have successfully t at o restored natural forest habitats. Experiments have been conducted on ue t r have been accident enhancement of marine ecosystems by building ''artificial reefs.'' There is a y t a great need to develop methods to restore, create, and enhance ecosystems and to represent m are

l strengthen the science base underlying them. This includes careful monitoring a of projects and dissemination of the information, whether they succeed or fail. errors In some cases, such as wetlands, regulations are ahead of science. To support

age breaks the national goal of "No Net Loss" of wetlands, regulators may require wetlands P is new digit

h creation or restoration as a condition of permitting activities in wetlands. pographic y iles. T t

However, issuing a permit does not necessarily make it possible to create a f e ile: ng i f functioning wetlands ecosystem. Generally, more funding agency support and t F

D more attention from the academic community are needed to support the P peset and som

is emerging field of restoration ecology. y h t

Environmental planning and management are not emphasized in academic ined, a bout A ret original t

ion. om

r curricula in ecology or engineering, the two major disciplines required to ibut f r t cannot practice them. Courses in this subject should be available for majors in both of r at not

o these disciplines. Few universities require classes in ecology for engineering f students or engineering for ecologists. To achieve an environmentally

however, compatible development, engineers must have a basic understanding of the version ng,

t environments in which they will be working and environmental scientists must paper book, at ive learn some of the language and constraints of engineering. Sound at rm o environmental planning and management require the cooperative interaction of riginal horit ic f

o these disciplines. It would aid the process if this interaction began during the e h training of its practitioners. It is important to build a base of environmental t he aut t planners and managers in all countries. om r as ing-specif t Industries and government agencies participating in the environmental ion ed f planning and management process should also disseminate the information peset y gained from development projects. The possibility of a central bibliographic publicat

her t database should be explored. iles creat is h t L f

M of

and ot

X MOVING TOWARD SUSTAINABLE DEVELOPMENT om yles, r f If there is a chance to preserve natural habitats and the biodiversity they st version support, it will not be enough to focus on creating parks and refuges and print posed

e conducting biological Surveys. Parks and refuges are of value in that they h heading preserve samples of diversity. Inventories are essential, but they document what recom

use t is being lost while doing little to reverse the trend. A long-term solution to the problem requires that more attention be given to land that will be "used," that is, breaks, ease l been

P to develop methods that allow use of the land while maintaining its ecological

word

has integrity and functions. This area has not received much attention from the ed.

hs, academic community or national funding agencies. Few "developers" (from

insert slash-and-burn colonists in the rain forest to housing developers in the United

ally States) have the resources to conduct the long-term studies required even to line lengt inventory the species that are Present, much less to gain a complete original work e h

t understanding of the systems in which the development will take Place. Yet ecologically based management methods must be applied if natural systems are he original;

ion of to be maintained outside parks and preserves. t at o The following are examples of questions that need the attention of the ue t r have been accident research community and funding agencies. y t a Will undisturbed corridors in the midst of a development maintain the represent m are

l overall ecological integrity of the system? How large should corridors be? What a configurations? errors Which has less ecological impact overall, high-density or low-density

age breaks housing? What are the ecological and social trade-offs? P is new digit

h What kinds of monitoring can best and most cost-effectively indicate when pographic y iles. T t

f an activity is damaging an ecosystem? When is a damaged system "recovered?" e ile: ng i f Is it possible to determine when a "restored" system is self-sustaining? t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r How clean is "clean" in the ecological sense? For example, in cleaning up ibut f r t cannot an oil spill, is ecological recovery faster if some oil is left in the environment r at not

o rather than using extreme measures, such as high-pressure hot water, to remove f it?

however, Are there methods to restore damaged or degraded habitats more version ng,

t effectively than natural recovery? Which methods are ineffective or actually paper book, at ive increase damage or prolong recovery? at rm o These questions identify areas of research and reporting that have "fallen riginal horit ic f

o through the cracks." They are not seen as part of the mission of any agency or e h funding group. Yet there is a great need to develop the science base in these t he aut t

om areas that have practical and immediate application. To develop the methods r as ing-specif t requires the collaboration of environmental scientists and engineers, much the ion ed f way in which AIOGC developed unconventional strategies for its Ecuador peset y development project. One further element is required for implementation of publicat

her t sound environmental planning and management practices, a supportive iles creat is h

t regulatory framework. L f

M of

and ot X om yles,

r DISCUSSION f st version The Villano Field oil discovery in Ecuador is requiring ARCO to become print posed

e innovative in designing an exploration and development plan with the goal of h heading minimizing environmental and social impacts. A key feature of ARCO's work recom

use t in the area is that oil exploration was conducted and a plan was developed for oil production and transportation without construction of new roads and with a breaks, ease l been

P significantly reduced "footprint." Although operations have been conducted

word

has elsewhere without constructing roads to remote areas, the ARCO concept is a ed.

hs, significant departure from conventional operations, with clear environmental

insert and social benefits. By applying lessons learned from oil operations around the

ally world and encouraging creative technical thinking, a plan is being developed line lengt which is operationally sound, cost-effective, and proven by application in an original work e h

t offshore environment. The plan is consistent with the environmental and cultural objectives of the company and the indigenous people in the area. he original;

ion of There is the broader question of whether to develop oil resources in t at o Ecuador or in other rain forests. The fact is that oil development will occur in ue t r have been accident Ecuador; the country's economy depends on oil revenues. If ARCO does not y t a produce the oil, some other company probably will do so by making use of represent m are

l conventional technology and practices now common in the area. The approach a described in this paper is, in ARCO's view, a major advance in environmental errors protection that has application beyond the single project.

age breaks A major effort is needed to strengthen the science base as well as train and P is new digit

h encourage scientists and engineers to practice the innovative thinking and pographic y iles. T t

f collaboration required to implement sound environmental planning and e ile: ng i f management. Environmental scientists and engineers in the academic t F

D community must develop programs to promote this field. Industry scientists and P peset and som

is engineers must be y h t

ined, a bout A ret original t

ion. om

r empowered to take risks and think unconventionally, since it is through them ibut f r t cannot that most new ideas will be generated and applied in the field. Governments r at not

o need to develop regulatory frameworks that support, rather than impede, this f process. Supporting and encouraging sound environmental planning and

however, management offers some hope that the ecological integrity and functions of version ng,

t natural systems may be maintained when development occurs. paper book, at ive at rm o riginal horit

ic f REFERENCES o e

h AIOGC. 1990. Guidelines for Exploration in the Tropical Rain Forests of Eastern Ecuador. Safety, t he aut t

Health and Environmental Protection Department, ARCO International Oil and Gas Co., om r

as Plano, Texas. ing-specif t Angermeier, P. L., and J. R. Karr. 1994. Biological integrity versus biological diversity as policy ion ed f directives. BioScience 44(10):690-697. peset

y Brokaw, N. V. L. 1982. Treefalls: Frequency, timing and consequences. In The Ecology of a Tropical Rain Forest, E.G. Leigh, Jr., A. S. Rand, and D. M. Windsor, eds. Washington, publicat

her t D.C.: Smithsonian Institution Press. iles creat is

h Brown, N., and M. Press. 1992. Logging rainforests the natural way? New Scientist 133(1812) t L f (March 14):25-29. M of

and ot

X Connell, J. H. 1979. Tropical rain forests and coral reefs as open non-equilibrium systems. In Population Dynamics, R. Anderson, B. Turner, and L. Taylor, eds. Oxford, England: om yles, r f Blackwell Press. st version Holdridge, L. R. 1967. Life Zone Ecology, rev. ed. San Jose, Costa Rica: Tropical Science Center. Lewis, S. 1990. The Rainforest Book. Los Angeles: Living Plant Press. print posed

e Lindstedt-Siva, J., and D. W. Chamberlain. 1991. Petroleum Operations in Ecuador: h

heading Recommendations for Environmentally-Based Oil Development in a Tropical Forest.

recom Report to ARCO International Oil and Gas Co., Plano, Texas.

use t Loll, S., and R. Steinbauer. 1993. Coles Levee and North Dauphin Island win ARCO Environmental

breaks, Award in AOGC "sweep." Environmental News 12(3):1-2. ease l been Lovejoy, T. E. 1994. People and biodiversity. Nature Conservancy 44(1) (January/February):29-33. P McMeekin, D. T. 1991. Report on Environmental and Ethnic Issues During All Phases of the word has ed. Development of the Moretecocha I Well Location, ARCO Oriente, Inc. D.T.M. Cia. Ltda, hs, Quito, Ecuador, October 1.

insert McMeekin, D. T., and V. Zak. 1990. A Survey of the Physical Environment: Moretecocha Well Location, ARCO Oriente, Inc. D.T.M. Cia. Ltda, Quito, Ecuador. May. ally National Research Council. 1980. Research Priorities in Tropical Biology. Washington, D.C.: line lengt

original work National Academy Press. e

h National Research Council. 1982. Ecological Aspects of Development in the Humid Tropics. t Washington, D.C.: National Academy Press. National Science Board. 1989. Loss of Biological Diversity: A Global Crisis Requiring International he original;

ion of Solutions. A Report to the National Science Board Task Force on Biological Diversity. t at o Publ. NSB-89-171. Washington, D.C.: National Science Foundation. Raven, P. H. 1994. Defining biodiversity. Nature Conservancy 44(1) (January/February):10-15. ue t r have been accident y

t Roberts, L. 1991. Ranking the rain forests. Science 251:1559-1660. a Wilson, E. O. 1988. Biodiversity. Washington, D.C.: National Academy Press. represent m are

l Woodward-Clyde, International. 1992. Environmental Impact Evaluation, Proposed Exploratory a Well Villano No. 3, Villano, Oriente Basin, Ecuador. errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 163 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om r ibut f r t cannot r at not Lessons in Water Resource and Ecosystem o f Regulation from Florida's Everglades and however, version ng,

i California's Bay/Delta Estuary t paper book, at ive at rm o riginal horit ic f o e

h John R. Wodraska and Peter E. Von Haam t he aut t

om r as ing-specif t THE VALUE OF NEGOTIATED FLEXIBILITY ion ed f peset

y Secretary of the Interior Bruce Babbitt stated recently that the two most

publicat perplexing issues in water management in the United States were in Florida and her t iles creat is

h California. He was referring to environmental controversies in the Everglades in t L f

M of southern Florida and California's San Francisco Bay/Sacramento-San Joaquin

and ot X Delta (Bay/Delta). om yles, r

f Two main lessons emerge from events surrounding the Everglades and the st version Bay/Delta. First, regulations aimed at improving water quality and habitat are

print most effective when they embody an incremental approach with frequent posed e h

heading evaluation and updates. Conversely, large-scale, irreversible, and sweeping

recom programs tie the hands of resource managers and prevent new programs that can use t elicit the broad-based support necessary to sustain any long-term management breaks, ease l been strategy. P Second, negotiated understandings and agreements involving state and word has ed.

hs, federal resource agencies and local stakeholder groups are effective ways to develop mutually acceptable solutions. Once resolution of such complex insert environmental matters becomes embroiled in litigation, it becomes extremely ally

line lengt difficult to realize an adequate solution. original work

e This paper first compares the geography and history of the Everglades and h t the Bay/Delta. It then examines the political and legal events surrounding the Everglades controversy and the lessons of those events for the Bay/Delta crisis he original; ion of t at o and other resource management cases. ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 164 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r SIMILARITIES BETWEEN THE EVERGLADES AND THE ibut f r t cannot BAY/DELTA r at not o

f The Everglades and the Bay/Delta are strikingly similar in physical geography and social importance. however, version ng,

i t paper book, at ive Florida's Everglades at rm o riginal horit

ic f The Everglades are a wetland ecosystem significantly altered by human o

e development. In this ecosystem's natural state, water flowed southward from the h t he aut

t Kissimmee chain of lakes along the meandering Kissimmee River into Lake

om r as ing-specif Okeechobee, an expansive shallow-water lake in the south-central part of the t ion

ed f Florida peninsula (Figure 1). When heavy summer rains occurred, Lake peset

y Okeechobee flooded, and the water drained southward in a "river of grass," 50 miles wide and 6 inches deep through the region called the Everglades. Weather- publicat her t iles creat is related changes in the water level of the lake created a complex ecosystem h t L f dependent on varying water flows (Mairson, 1994). M of

and ot

X These naturally variant conditions, in part, created the need to pursue om yles,

r development projects in the Everglades from the early 1900s to the 1960s. f st version Hurricane-induced flooding caused losses in human life and property, and extended droughts caused overdrafting of groundwater basins that provided print posed e

h water for cities and agriculture. In response, the state and federal government heading created an extensive flood control and water conveyance system (Light et al., recom use t 1989). They confined the Kissimmee River into a straight canal, diked Lake breaks,

ease Okeechobee to prevent flooding, and reclaimed some 6 million acres of l been P wetlands south of the lake, mostly for agriculture, by building canals and levees word has ed. to funnel water toward the coast. After completion of the projects, all flows into hs, Lake Okeechobee and the Everglades were controlled by gates and pumps. By insert 1953 five major canals totaling 440 miles existed in the area. The canals took ally

line lengt water from the marshlands and diverted it for agricultural use or for original work

e groundwater recharge for later urban and agricultural pumping. The fertile, dark h t

peat soils of the Everglades are prone to subsidence, and levees are required to protect the reclaimed land from flooding. he original; ion of t at

o These projects, however, came at a high environmental cost. The reduced and confined flows into the Everglades and the high phosphorus levels in ue t r have been accident y t agricultural drainage degraded the natural ecosystem. Increased nutrient levels a represent m

are and modified water levels caused a monoculture of cattails to overcome native

l a saw-grass in many areas. Water bird abundance has declined dramatically errors because of diminished habitat and the effect of reduced flow on the fish populations that provide the birds' food source (Light et al., 1989). age breaks

P The importance of the Everglades in Florida's economy underscores the is new digit h pographic

y importance of maintaining the ecosystem in a condition that can satisfy the iles. T t

f e

ile: competing uses of its waters. Agricultural areas rely on canals for direct ng i f t

F diversions and for recharging groundwater. Cities also draw their water supplies D from P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 165 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of

t FIGURE 1 The Everglades. SOURCE: South Florida Water Management at o District. ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 166 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r aquifers fed by the canals, and the fish and wildlife of the Everglades ibut f r t cannot depend on sufficient flows to sustain their critical habitats. r at not o f The San Francisco Bay/Sacramento-San Joaquin Delta however, version ng,

t Like Florida's Everglades, the Bay/Delta in California is a stressed paper book, at ive ecosystem that plays a vital role in the state's water resource and economic at rm o infrastructure (Figure 2). The Bay/Delta also is a complex water system altered riginal horit ic f

o significantly by human development. e h Before development the confluence of the Sacramento and San Joaquin t he aut t

om Rivers, along with numerous mountain tributaries, formed a massive inland r as ing-specif t marsh of 750,000 acres. Freshwater from upstream mixed with seawater ion ed f entering with the tides from San Francisco Bay and the Pacific Ocean. Spanish peset y explorers in the eighteenth century described the delta as a "sea of reeds." The publicat

her t shallow waters, foliage, and brackish quality of the water nurtured a rich fishery. iles creat is h t

L f After the gold rush, settlers began reclamation projects to drain the

M of

and ot marshlands for farming. They built canals to divert water from the reclaimed X lands and levees to prevent flooding. By the tune this massive reclamation om yles, r f effort was completed in 1930, the landscape of the delta had completely st version changed. More than 500,000 acres had been enveloped by 1,100 miles of print posed

e levees. The sea of reeds had become an island archipelago of some 70 islands h heading encircled by more than 700 miles of rivers, sloughs, and channels. Most of these recom

use t islands have supported agriculture, with corn as the most important crop, along with safflower, sugar beets, alfalfa, wheat, and others. The peat soils, similar to breaks, ease l been

P those in the Everglades, were susceptible to subsidence and flooding, so

word

has agriculture was and still is a risky enterprise (Schwarz, 1991). ed.

hs, Conditions in the delta required development of other water projects.

insert Salinity levels in the delta historically varied greatly according to weather

ally patterns, and during the severe drought years of the early 1930s, salt water line lengt reached all the way upstream to Sacramento and Stockton. Beginning in the late original work e h

t 1800s and throughout this century, water projects were built to control flooding, divert water from upstream tributaries, and export water for agricultural and he original;

ion of urban use. The two largest reservoirs, Oroville and Shasta, retain water t at o throughout the year, providing higher flows during the dry season and enabling ue t r have been accident water managers to control salinity intrusion into the delta. The State Water y t a Project and federal Central Valley Project (two of the largest public works represent m are

l projects in the nation) include diversion facilities in the southern end of the a delta to export water southward through the Delta Mendota Canal and errors California Aqueduct (Figure 3).

age breaks Today the Bay/Delta serves as the hub of California's water supply system. P is new digit

h The federal and state water projects divert water from the delta into aqueducts pographic y iles. T t

f that convey water southward into the San Joaquin Valley agricultural areas and e ile: ng i f then pump it 2,000 vertical feet over the Tehachapi Mountains into the urban t F

D communities and farms of southern California. The North Bay and South Bay P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 167 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t FIGURE 2 Delta waterways. SOURCE: California Department of Water breaks, ease l been Resources. P

word has ed.

hs, aqueducts serve urban users in the San Francisco Bay Area. In addition, riparian farmers in the delta divert water for irrigation, agricultural water insert districts in the Sacramento and San Joaquin river basins take water from the ally

line lengt system, and the City of San Francisco and East Bay Municipal Utility District original work

e (serving Oakland and Berkeley) store and divert water upstream of the delta for h t urban use. Like the Everglades, the Bay/Delta has experienced environmental he original; ion of t at o problems in recent decades. Exports from the delta and upstream diversion

ue t primarily for agricultural use have reduced the amount of freshwater flowing r have been accident y t

a through the delta and altered flow patterns through the channels, with negative represent m are

effects on fish populations. Introduction of nonnative species, polluted l a agricultural runoff, poaching, local land-use changes, and droughts also errors contributed to the widespread decline of fish species in the Bay/Delta. The winter-run chinook salmon and delta smelt have been listed as endangered and age breaks P

is new digit threatened, respectively, h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 168 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs,

insert FIGURE 3 Major features of state water project and Central Valley project. ally line lengt

original work under the federal Endangered Species Act (ESA). These listings e h t significantly constrain operation of the pumping facilities in the southern delta,

as the pumps must shut down for significant periods to prevent entrainment of he original; ion of

t these fish. These periodic shutdowns have significantly decreased the reliability at o of supplies from the delta, jeopardizing water plans of agencies throughout

ue t 1 r have been accident California. y t a California's water supply infrastructure is the backbone of the state's represent m are

a economy. Factors diminishing the reliability of the water supply, such as the

errors environmental problems in the Bay/Delta, threaten California's economic

future.2 Therefore, there can be no distinction between protecting the

age breaks environment P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 169 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r and promoting California's economy in the case of the Bay/Delta. The two goals ibut f r t cannot are inextricably linked, and developing an acceptable solution to the conflict r at not

o will sustain both the resources and future economic activity. f however,

version THE EVERGLADES CONTROVERSY ng,

i t paper book, at ive Concerns over the ecological health of the Everglades led in 1970 to at rm o congressional legislation mandating minimum flows into Everglades National riginal horit ic f 3

o Park. Although the park was unquestionably affected by the canals, levees, e h pumps, and water control structures that regulate flows into the area, it was t he aut t

om unusual for Congress to micromanage such a complex ecosystem by r as ing-specif t legislatively mandating specific flow requirements. The results of this program ion ed f were clearly detrimental to the environment. The timing and magnitude of flows peset y were inappropriate, exaggerating natural extremes (Light et al., 1989). The publicat

her t ecosystem continued to decline, prompting an emotional public reaction that set iles creat is h

t the tone for future political and legal developments. L f

M of

and ot In retrospect, the inflexibility and sweeping character of the congressional X requirements doomed the flow standards from the beginning. There were no om yles, r f built-in mechanisms for monitoring environmental effects of the standards or st version for modifying them to meet the demands of changing natural hydrologic print posed

e conditions. This omission tied the hands of resource managers in the h heading Everglades' highly dynamic, variable, and unpredictable ecosystem. In short, recom

use t the program embodied the characteristics of ineffective environmental regulatory schemes—rigid standards that precluded appropriate ecological breaks, ease l been

P decision making.

word has ed. hs, The Role of the South Florida Water Management District insert

ally In 1983 severe high-water conditions in Everglades National Park line lengt eliminated the wading-bird nesting season, and the Everglades Research Center original work e h

t (part of the National Park Service) told the South Florida Water Management District (SFWMD) that an ''ecological emergency'' threatened the park. Later he original;

ion of the Park Service asked for a comprehensive restoration plan including changes t at o in flow distribution and intentional breaching of levees and filling in of canals ue t r have been accident to return flows to the approximate levels that existed before widespread y t a development. represent m are

l The Florida legislature had expanded SFWMD's duties from traditional a flood control and water supply to include issuance of permits for certain types errors of water use, surface water and stormwater management, land acquisition for 4 age breaks riverine habitat restoration, and water quality protection. This new mission P is new digit

h made SFWMD stewards of environmental uses, as well as water uses, and pographic y iles. T t

f expanded its role in resolving the Everglades crisis. e ile: ng i f In response to its new role in the controversy, SFWMD developed a two- t F

D pronged program to resolve the issue. The first part involved alternative dispute P peset and som is resolution (ADR), an approach to consensus building that seeks to identify y h t

common ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 170 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r ground among various parties and to build agreements based on mutual ibut f r t cannot interests. The other aspect of the program was SFWMD's iterative testing r at not

o process (ITP), a progressive approach to resource management emphasizing f incremental testing and evaluation of the effects of environmental regulation

however, and active integration of ecological forces into the regulatory decision making version ng,

t process (Light et al., 1989). paper book, at ive at rm o riginal horit

ic f Alternative Dispute Resolution o e h To break the gridlock that had precluded a mutually acceptable solution, t he aut t

om SFWMD developed an approach involving negotiation and consensus building r as ing-specif t among groups having historically disparate interests, such as environmentalists ion ed f and sugarcane growers. The District found that even amidst long-standing peset y disputes with deeply entrenched positions, small but meaningful steps toward publicat

her t collaborative problem solving could take place. Good-faith negotiations, in turn, iles creat is h

t unlocked doors for much bolder and meaningful strategies based on increased L f

M of

and ot understanding and attention to safeguards (Light et al., 1989). X The District's commitment to ADR required expenditure of much energy om yles, r f on outreach and required that technical findings be made available for scrutiny st version by others. In the long run, this fostered greater trust and respect for the District's print posed

e abilities and intentions. For example, SFWMD avoided litigation with farmers h heading who, contending that the risk of flooding was too great, protested SFWMD's recom

use t plan to modify flow patterns around Everglades National Park. Using ADR methods, the District negotiated an agreement with the farmers whereby the breaks, ease l been

P District operated short-term test-diversions to monitor effects on flood risk.

word

has This experience suggests that taking small steps, such as experimental testing, ed.

hs, can pave the way for more ambitious future programs by minimizing the

insert perceived risk to interested parties who might feel threatened by new and

ally innovative approaches. line lengt original work e h t Iterative Testing Process he original;

ion of The District recognized that water management interventions in the t at o Everglades over the past 80 years (for both development and environmental ue t r have been accident purposes) had been too sweeping and rigid and failed to integrate ecological y t a processes. As a result, these decisions contributed to the degradation of the represent m are

l Everglades' resources. The District sought an alternative to the traditional water a planning approach, which had few built-in mechanisms for remedial action. The errors Everglades case needed an approach to water management that fostered testing

age breaks of policies and technical measures on a scale sufficient to be highly informative, P is new digit

h while limiting environmental risks. pographic y iles. T t

f The District developed ITP as a new approach to water management (Light e ile: ng i f et al., 1989). The key to this new approach was incremental changes followed t F

D by systematic testing and analysis to gauge environmental responses to those P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 171 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r changes. This feedback would guide the next resource management decision, ibut f r t cannot permitting the modifications necessary to achieve the ecological objective. One r at not

o salient feature of this approach is the integration of ecological processes into f decision making. Making incremental changes and modifications enables

however, scientists to see how natural processes affect and react to environmental version ng,

t modifications. By permitting natural response mechanisms to guide and paper book, at ive calibrate the water management measures in this way, latent and healthy at rm o ecological patterns can emerge.5 Unfortunately, the District's ITP programs riginal horit ic f

o were not able to come into full effect because of litigation that drastically e h affected the water management process in the Everglades. t he aut t

om r as ing-specif t ion

ed f Litigation Developments peset y Beginning in October 1988, a major lawsuit and associated settlement publicat

her t negotiations dominated the Everglades debate. In that month, the U.S. Justice iles creat is h t

L f Department sued SFWMD to enforce state water quality standards. The Justice

M of

and ot Department filed suit in federal court under state law rather than federal law, X because the Federal Clean Water Act did not apply to polluted runoff from om yles, r f farming operations that were discharging phosphorus into the Everglades st version through a federal water project facility. print posed

e The water quality standards that SFWMD was responsible for enforcing h heading were narrative, or nonnumeric. The law stated that concentrations of nutrients, recom

use t such as phosphorus, must cause "no imbalance in the flora or fauna" of the region. There always had been controversy surrounding how to translate this breaks, ease l been

P narrative standard into numerical ones and whether the standards were working.

word

has After the lawsuit was initiated, Florida's new governor, Lawton Chiles, ed.

hs, entered federal court and declared, "We want to surrender. I am here. I have

insert brought my sword. Who do I give it to?" (Palm Beach Post, 1994). In July 1991

ally the state and federal governments reached a settlement agreement that included line lengt conversion of some farmlands into marshes to filter out phosphorus and original work e h

t establishment of phosphorus reduction targets. The estimated cost of the program was $465 million. he original;

ion of Certain aspects of the agreement embodied principles of the iterative t at o testing process, as discussed above. The agreement stipulated that a panel of ue t r have been accident scientists would determine numerical interpretations of the narrative phosphorus y t a criteria. This interpretation would become the temporary "numerical standard." represent m are

l The panel would evaluate the results and suggest adjustments based on the a monitoring data. The agreement attempted to represent the incremental, errors flexible, and systematic approach SFWMD had been advocating.

age breaks Again, however, litigation delayed implementation of the new approach. P is new digit

h Sugarcane growers challenged the legality of the agreement, contending that the pographic y iles. T t

f federal government was illegally interfering with the state's sovereignty over e ile: ng i f water issues. In the summer of 1993, Secretary Babbitt announced a framework t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 172 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r agreement between two of the three major sugar firms regarding the allocation ibut f r t cannot of restoration costs. One of those firms broke off talks with the Interior r at not

o Department in December 1993. f however,

version Recent Developments ng,

i t paper book, at ive In May 1994 the Florida Supreme Court overturned a ballot initiative that at rm o sought to levy a one-cent-per-pound tax on raw sugar and to use the proceeds riginal horit ic f

o for an Everglades restoration trust. The court ruled that the initiative violated e h the "single-subject rule" because the restoration trust would have performed t he aut t

om functions of legislative, executive, and judicial branches, in violation of the r as ing-specif t Florida constitution. In addition, the court ruled that the title and summary of ion ed f the measure were misleading.6 peset y At the time of this writing, the Florida legislature had just passed the publicat

her t Everglades Forever Act, a comprehensive program for restoring the Everglades iles creat is

h 7 t

L f ecosystem. While the timing of the passage of the act prevents detailed

M of

and ot treatment here, it is possible to summarize some of the more important X provisions. The act will generate more than $700 million over 20 years (more om yles, r f than $300 million from agriculture) for various activities aimed at improving st version water quality and water supply throughout the historic Everglades, including print posed

e Lake Okeechobee, the agricultural areas in the region, Everglades National h heading Park, and urbanized areas of the southeast coast. recom

use t The Everglades Forever Act seeks to improve water quality through increased inflows to the "protected areas" of the Everglades, an ambitious breaks, ease l been

P research and monitoring program, directions to the state Department of

word

has Environmental Protection to establish new phosphorus criteria before the year ed.

hs, 2003, and establishing time lines for construction of new stormwater treatment

insert areas. The financing for these programs will come primarily from a tax on

ally agricultural lands (ranging from about $25 per acre annually in 1994 to $35 in line lengt 2013) and an increase in property taxes in the 15 counties that make up the original work

e 8 h

t Everglades region.

he original; ion of t at

o Lessons from the Everglades Controversy ue t r have been accident The Everglades controversy provides several lessons in the institutional y t a aspects of water resource management. The unique geography of the represent m are

l Everglades and its history of human modifications suggest that regulatory a programs should adopt an incremental, flexible, and monitored approach as errors embodied by SFWMD's iterative testing process. The Everglades controversy

age breaks also demonstrates that ambitious negotiation programs provide the best hope for P is new digit

h finding a workable solution that is acceptable, at least in part, to all interests. pographic y iles. T t

After the litigation process began to drive the Everglades dispute, resource f e ile: ng i f managers and others lost the ability to fashion creative solutions. t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 173 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r THE BAY/DELTA CRISIS ibut f r t cannot In California, the State Water Resources Control Board (State Board) is the r at not o

f agency with primary authority over water quality and water allocation. As such, the State Board is responsible for formulating water quality plans and for however,

version regulating rights to the use of waters of the Bay/Delta. The State Board also has ng,

i t paper book, at ive the duty to protect uses of water for agriculture, cities, and fish and wildlife. at rm Two key regulatory parameters for protection of the Bay/Delta's beneficial o riginal horit

ic f uses are flow and salinity. The two are interrelated, because the timing and o

e magnitude of freshwater flows can affect salinity levels at various locations in h t he aut

t the Delta. In 1978 the State Board adopted a Water Quality Control Plan as

om r as ing-specif required by the federal Clean Water Act (CWA) and also adopted a water rights t ion

ed f decision under state law to implement the plan. The State Board's water rights peset

y decision (Decision 1485) included flow and salinity requirements and focused regulations solely on the State Water Project and the federal Central Valley publicat her t iles creat is Project. h t L f As generally required by the CWA, the U.S. Environmental Protection M of

and ot

X Agency (EPA) reviewed the Water Quality Control Plan for approval and om yles,

r conditioned its approval on commitments from the State Board to improve f st version aspects of Decision 1485 for fish and wildlife if fishery declines indicated a necessity. When the striped bass population declined in the late 1970s and early print posed e

h 1980s, the State Board took no significant actions in response to EPA's request. heading The Water Quality Control Plan and Decision 1485 also received intense recom use t scrutiny under state law in state court. The Racanelli decision in 1986 by a state breaks,

ease appellate court declared parts of the State Board's 1978 plan invalid, ruling l been P among other things, that the plan failed to consider the role of all Bay/Delta word has ed. watershed diverters, focusing instead only on the State Water Project and the hs, Central Valley Project.9 The State Board adopted a revised Water Quality insert Control Plan in 1991, but EPA disapproved it, claiming that changes made from ally

line lengt the 1978 plan were inadequate. original work

e In the fall of 1992, President Bush signed into law the Central Valley h t Project Improvement Act, which requires a significant portion (800,000 acre- feet per year from the project's approximate annual yield of 7 million acre-feet) he original; ion of t at

o of the Central Valley Project's water supply yield to go toward fisheries restoration, possibly including increased flows through the delta.10 The act also ue t r have been accident y t levies fees on users within the project's service area, with the proceeds used to a 11 represent m

are finance an ambitious fisheries habitat restoration program.

l a In response to a request from Governor Pete Wilson, the State Board in errors December 1992 released draft water rights Decision 1630, which was intended to provide "interim" standards for protection of the beneficial uses of the Bay/ age breaks

P Delta, with particular attention to fisheries protection. Draft Decision 1630, if is new digit h pographic

y adopted, would have affected most Bay/Delta watershed users and included iles. T t

f e

ile: extensive flow and salinity requirements designed to protect fish and their ng i f t

F habitats. In a historic shift of positions, urban water agencies throughout D northern and southern California P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 174 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r supported the environmental objectives of the proposal, while suggesting ibut f r t cannot modifications in the proposed regulations. This change was significant because r at not

o prior to that time, water agencies in northern and southern California rarely f adopted the same positions on issues such as Bay/Delta standards. To the

however, contrary, southern California water agencies along with San Joaquin Valley version ng,

t agricultural water districts had traditionally fought with agencies in northern paper book, at ive California. at rm o Governor Wilson requested the State Board on April 1, 1993, to stop work riginal horit ic f

o on draft Decision 1630, claiming that federal involvement in the Bay/Delta e h through enforcement of the Endangered Species Act made state action t he aut t

om "irrelevant." r as ing-specif t ion ed f peset

y EPA's Proposed Standards publicat

her t In response to the State Board's action on draft Decision 1630, the EPA iles creat is h t

L f proposed a set of standards in January 1994, claiming federal authority under

M of 13

and ot the CWA. The EPA proposal contained a salinity intrusion standard X mandating a fixed number of days for meeting a 2 part-per-thousand salinity om yles, r f level at various locations in the Bay/Delta estuary from February through June. st version EPA reached this formula from statistical analysis of past hydrologic print posed

e conditions, intending to recreate conditions as they existed in the late 1960s and h heading early 1970s (before significant levels of State Water Project exports from the recom

use t southern delta and a period that EPA believes had good habitat conditions for fisheries). breaks, ease l been

P Although generally supportive of Bay/Delta standards that are more

word

has protective of fisheries, urban water agencies in northern and southern California ed.

hs, objected to EPA's specific proposal on several grounds: (1) the standard was

insert unduly rigid and failed to include mechanisms for properly responding to

ally changes in precipitation and runoff within the year; (2) the plan, at times, would line lengt have placed the optimum salinity conditions for fisheries too far downstream original work e h

t from the most productive habitat zones; (3) the proposal lacked mechanisms for biological evaluation to accommodate adjustments to the standard based on he original;

ion of measured re-suits; and (4) legal questions existed regarding EPA's authority to t at o adopt and implement the type of standards proposed. ue t r have been accident Urban agencies invested substantial resources in analyzing EPA's proposal, y t a and attempted to produce an alternative that could better meet environmental represent m are

l objectives of the EPA proposal. As a result of extensive studies by technical a consultants and others, the urban agencies concluded that environmental errors objectives of the proposal could be met at a lower water cost. These studies

age breaks formed the basis of an "Urban Alternative" to EPA's proposal, sponsored by a P is new digit

h coalition of northern and southern California urban water agencies. pographic y iles. T t

f e ile: ng i f t

F "The Urban Alternative" D P peset and som is The alternative proposed by urban water agencies improves on EPA's y h t

proposal by providing flexibility, monitoring, and a foundation for realizing long- ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 175 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r term solutions to the Bay/Delta problem. EPA's proposed salinity standard ibut f r t cannot failed to account adequately for changing runoff patterns within the year. In r at not

o contrast, the Urban Alternative contains a sliding-scale methodology to permit f the standard to update itself periodically within the year to ensure that the

however, regulation responds to natural variations of hydrologic conditions. This version ng,

t approach is similar to the iterative testing process in Florida in that the standard paper book, at ive would incorporate natural ecological functions to guide regulatory decision at rm o making. riginal horit ic f

o The Urban Alternative also includes biological monitoring and evaluation, e h which EPA's proposal lacked. As discussed earlier, a systematic, incremental t he aut t

om plan for resource management requires monitoring to gauge effects of the r as ing-specif t standard on the environment. The Urban Alternative would require extensive ion ed f biological evaluation so that the standards could be updated periodically. peset y publicat her t iles creat is Long-Term Solutions h t L f

M of

and ot Immediate standards for the Bay/Delta are only the first step in resolving X the larger Bay/Delta issues, and the urban group advocates establishing a om yles, r f process for determining these long-term solutions. The preferred approach st version would include consideration of the ecosystem as a whole, using multispecies, print posed

e habitat-wide approaches instead of the single-species approach under the h heading Endangered Species Act, which lacks flexibility and balance. Long-term recom

use t analysis and solutions also would take into account factors other than delta exports and diversions that have contributed to fisheries declines, including breaks, ease l been

P drought, agricultural runoff, introduced nonnative species, and poaching.

word

has Finally, an environmental decision making process must take place to evaluate ed.

hs, water management alternatives to improve methods by which water is conveyed

insert through and diverted from the delta. ally line lengt original work

e CONCLUSION h t Experiences in the Everglades have much to teach resource managers he original;

ion of about institutional aspects of water regulation in a complex ecosystem. Flexible t at o and incremental approaches are far superior to rigid regulatory schemes that too ue t r have been accident often have prevailed. Negotiated agreements, which require creativity and y t a scientific determinations that the judicial system often cannot deliver, are far represent m are

l superior to court battles for making resource management decisions. a These principles apply equally to the current controversy in California's errors Bay/Delta. A group of urban water agencies from northern and southern

age breaks California has proposed an approach that incorporates characteristics of P is new digit

h effective regulatory processes. Because of the logical and scientific bases of this pographic y iles. T t

f alternative and the urban agencies' efforts to consult with political leaders and e ile: ng i f technical staff of the regulatory agencies, there is hope that mistakes made in t F

D the Everglades will not repeat themselves in California. P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html LESSONS IN WATER RESOURCE AND ECOSYSTEM REGULATION FROM 176 FLORIDA'S EVERGLADES AND CALIFORNIA'S BAY/DELTA ESTUARY e h t be

ion. om

r Notes ibut f r t cannot r at not

o 1. See "Joint Effort Holds Out Hope for California Water," Standard & Poor's Creditweek f Municipal, March 21, 1994, p. 112: "Probably the most far reaching action affecting water resources management in California in the past decade was the listing of the winter-run however, Chinook Salmon and the Delta Smelt, combined with the biological opinions that followed. The version ng,

i t

paper book, restrictions placed on water project operations contained in the biological opinions have at ive

at immediate and future consequences on delta water export capability." rm o 2. Idem: "The allocation of water supplies for consumption in California remains in gridlock as riginal horit ic f both federal and state legislators try to achieve a workable solution to the conflicting interests in o e

h the delta.... Problems faced by California water suppliers will have a generally negative impact t he aut

t on credit quality for years to come due to the economic impact and rising costs associated with

om r as

ing-specif water supply and reliability." t 3. Public Law 91-28, River Basin Monetary Authorization and Miscellaneous Civil Works ion ed f Amendments, Section 2: "[D]elivery of water from the central and southern Florida project to peset y the Everglades National Park shall be not less than 315,000 acre-feet annually ... or 16.5 per

publicat centum of total deliveries from the project for all purposes including the park, whichever is less." her t iles creat is

h 4. Water Resources Act of 1972, Chapter 72-299, Florida Statutes, 1972. t L f

of 5. The Domenigoni Valley Reservoir Project in Southern California is another example of

and ot

X iterative processes for environmental management. The Metropolitan Water District of

om Southern California, in conjunction with several state and federal agencies, manages a 9,000- yles, r f

st acre ecological reserve in conjunction with the Project. Biological managers evaluate version incremental changes in habitat conditions, and make adjustments to protect the ecosystem print

posed supporting sixteen species that are candidates for listing under the Endangered Species Act. e h

heading 6. In re. Advisory Opinion to the Attorney General—Save Our Everglades Trust Fund, 19 Florida Law Weekly S276, 1994. recom use t 7. Everglades Forever Act, 1994 Fla. Sess. Law Serv. 115 (West), amending Section 373.4592,

breaks, Florida Statutes. ease l been

P 8. Section 373.4592(6), Florida Statutes.

word

has 9. See United States v. State Water Resources Control Board, 182 Cal. App. 3d 82 (1986). The ed.

hs, popular name for the case derives from the appeals court jurist who wrote the opinion, Judge

insert John T. Racanelli. 10. See Public Law 102-575, Title XXXIV, Section 3406(b)(2). ally

line lengt 11. See Public Law 102-575, Title XXXIV, Section 3407(d)(2)(A). original work

e 12. See letter from Governor Pete Wilson to chairman of the State Water Resources Control h t

Board, April 1, 1993 (Sacramento Bee, April 2, 1993). 13. Environmental Protection Agency, Proposed Rule: Water Quality Standards for Surface he original;

ion of Waters of the Sacramento River, San Joaquin River, and San Francisco Bay and Delta of the t at o State of California. Federal Register Vol. 59, No. 4, p. 810, January 6, 1994. ue t r have been accident y t a represent m REFERENCES are

l a Light, S. S., J. R. Wodraska, and J. Sabina. 1989. The Southern Everglades: The Evolution of Water errors Management. National Forum, the Phi Kappa Phi Journal (Winter):11-14. Auburn University.

age breaks Mairson, A. 1994. The Everglades: Dying for help. National Geographic 185(4)(April):2-35. P is new digit Mayer, J. 1993. Governor backs off new rules for delta. Sacramento Bee, April 2. h pographic Palm Beach Post. January 23, 1994. The everglades fight. p. 1F. y iles. T t

f Schwarz, J. 1991. A Water Odyssey, the Story of the Metropolitan Water District of Southern e ile: ng i f California. Los Angeles: Metropolitan Water District of Southern California. t F Standard & Poor's Creditweek Municipal. March 21, 1994. Joint effort holds out hope for California D water. p. 112. P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ENGINEERING STUDIES BASED ON ECOLOGICAL CRITERIA 177 e h t be

ion. om r ibut f r t cannot r at not Engineering Studies Based on Ecological o f Criteria however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h Hsieh Wen Shen t he aut t

om r as ing-specif t GOALS IN RIVER ENGINEERING ion ed f peset

y Decades ago, hydropower plants were considered the most

publicat environmentally sound means of generating electricity because they produce her t iles creat is

h neither smoke nor nuclear waste. Gradually, however, the ecological t L f

M of consequences of dams and other river modifications have become appreciated.

and ot X In particular, the environmental impact of the Aswan Dam in Egypt raised om yles, r

f many concerns with regard to hydropower development. Gradually we learned st version the need to live in harmony with our environment. Streams are not just conduits

print for supplying water for human needs; they are also communities of species. posed e h

heading This paper discusses the general goal of attempts to improve the ecological

recom properties of rivers, describes alternative specific objectives, and reviews two use t Cases that provide insights into the potential for collaboration between breaks, ease l been ecologists and engineers. P The general goal for ecological development in a stream is to achieve a word has ed.

hs, sustainable condition so that human beings can live in harmony with their environment. The World Commission on Environment and Development insert (known popularly as the Brundtland Commission) defined sustainable ally

line lengt development as "development that meets the needs of the present without original work

e compromising the ability of future generations to meet their own needs" (World h t Commission, 1987). Many international and national organizations, including the United Nations, UNESCO, World Bank, and the Earth Council have held he original; ion of t at o meetings to discuss various concepts of sustainable development and

ue t sustainability indicators. In general, ecologists treat "sustainability" as r have been accident y t

a preservation of the natural function and status of the ecological system, whereas represent m are

economists emphasize the maintenance and improvement of human living l a standards as indices for sustainability. errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r Two key questions arise: ibut f r t cannot 1. How much should we emphasize human interests in defining ecological r at not o goals? f 2. How do we define and achieve sustainability in the ecological aspects of however, stream systems? version ng,

i t paper book, at ive No precise answer can be given for either of these questions. When human at rm interests conflict with those of another species, one must judge the appropriate o riginal horit

ic f goal and approach for each problem. Sustainability with regard to stream o

e ecology is also difficult to define. Maintenance may be required to sustain h t he aut

t certain aspects of streams. The following examples may be instructive.

om r as ing-specif t ion ed f ALTERNATIVE OBJECTIVES peset y It is possible to distinguish four alternative objectives for projects intended publicat her t iles creat is to improve ecological conditions in streams and rivers. h t L f

M of 1. Restore to natural condition or a selected previous condition. Ecological

and ot X processes are dynamic. Some processes are known now and others may om yles, r

f not be known now or ever. Ideally, one wishes to enhance ecological st version conditions to satisfy future needs, but unfortunately this is difficult to print

posed achieve, especially for diverse collections of species. A common e h

heading approach is to attempt to restore a river basin to a natural or previous

recom condition. It is assumed that if the future hydrological condition is the use t same as that of the selected previous condition, then the majority of the breaks, ease l been ecological criteria will be satisfied. It is generally not feasible to return a P

word particular stream in the United States to its condition during pre- has ed.

hs, Columbian time. Rather one is more likely to achieve success by

insert returning the stream to a more recent condition. This general approach is particularly attractive when directed at diverse biological communities. In ally

line lengt this approach, one must investigate the previous conditions such as the original work e frequency and the extent of flooding and the ranges of various flow h t parameters such as flow depths and flow velocity. The case study on the

he original; Kissimmee River is a good example of this approach. ion of t at o 2. Achieve certain specific ecological criteria. If the ecological criteria for

ue t certain species can be determined, then an alternative is to restore or r have been accident y t

a maintain the river basin according to their specific needs, such as flow represent m are

l parameters required by different life stages, the magnitude and frequency a of flooding, acceptable levels of sediment in the flow, and various water errors quality limits. A great deal of research is needed to understand the ecological criteria for many ecological elements under various hydrologic age breaks P is new digit conditions. The case study of the Niobrara River (below) is a good h pographic y iles. T

t example of this approach.

f e ile:

ng 3. Maintain stable streams. The third, less satisfactory alternative is simply i f t F to design a stable stream system. This may or may not satisfy various D P

peset ecological and som is y h t

ined, a bout A ret original t

ion. om

r criteria. A dynamic stream may be more suitable in a dynamic ecological ibut f r t cannot evolution. r at not

o 4. Follow a combination approach. Often, the restoration of a river basin to f its natural condition must include considerations of both ecological

however, criteria and the stability of the streams such that the three preceding version ng,

t approaches must be combined. paper book, at ive at

rm Regardless of the particular objective, successful enhancement of a stream o

riginal will usually require integrated efforts by specialists from many fields. Public horit ic f o

e involvement is also critical. The following case studies demonstrate the h t

he aut importance of cross-disciplinary collaboration and public involvement. t

om r as ing-specif t ion ed f Kissimmee River Restoration Studies peset y The channelization project in the Lower Kissimmee River Basin, Florida, publicat her t

iles creat resulted in severe losses of river floodplain wetlands and waterfowl populations is h t L f throughout the river valley. An earthen channel, the C-38 canal, is the main M of

and ot element of this project. Immediately after project completion in 1971, a strong X

om effort was initiated to restore this basin to its prechannelization status. This yles, r f st version large Kissimmee River restoration project, when it is completed, will be a milestone in our journey toward ecological harmony because the only major print posed e goal of the project is ecological enhancement. In 1986 engineers and scientists h heading from the University of California, Berkeley, working with the South Florida recom

use t Water Management District, developed a set of restoration options. Ecological

breaks, goals for the restoration plans were formulated. Alternative restoration plans ease l been P

were evaluated for their potential to satisfy the ecological goals. Analyses were word has

ed. based on a combination of field data, physical modeling, and numerical hs, modeling. Finally, backfilling of certain reaches of canal C-38 was insert recommended. Details of this study are provided in Shen et al. (1994).

ally In most rivers, the ecological environment is the result of long-term line lengt

original work adjustments by countless complex factors. Many of these factors and their e h t

interrelated processes are extremely difficult, if not impossible, to define. Thus, ecologists stress the need to restore a river basin to natural conditions after the he original; ion of

t occurrence of man-made changes. Unfortunately, in the Kissimmee River at o Basin, human activities have changed the upstream conditions so much that the ue t r have been accident

y level of Lake Kissimmee cannot be allowed to fluctuate as much as it did before t a channelization. Thus, it is necessary to establish a set of ecological criteria as represent m are

a the targets for restoration, rather than attempt to recreate prechannelization errors

conditions. Alternative restoration plans must then be rated on the basis of their likelihood to achieve these criteria.

age breaks As in many other restoration projects, it is difficult to establish generally P is new digit h

pographic accepted ecological criteria because people representing various concerns stress y iles. T t

e different ecological goals. Conflicting requirements may even be proposed by ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r the same group of people. Thus, the first task in our study of the Kissimmee ibut f r t cannot River restoration was to search for a set of ecological criteria. These criteria r at not

o must be ecologically justifiable and feasible, because if they are too restrictive f then all feasible alternative measures can be eliminated. After many site visits,

however, the principal investigator gradually satisfied the various interest groups that the version ng,

t study was sincerely searching for the most feasible plan for ecological paper book, at ive restoration of the Kissimmee River. A symposium, suggested by the team and at rm o organized by the South Florida Water Management District, was held at riginal horit ic f

o Orlando in October 1988 to discuss various ecological and engineering e h concerns. This symposium was designed to focus on the restoration of the t he aut t Kissimmee River ecosystem as a whole rather than individual species. A set of om r as ing-specif t ecological restoration criteria was established. Their details will be discussed ion ed f later. In essence, restoration requires that the floodplain receive flow relatively peset y frequently to serve as a wetland. Also, floodwaters should return to the original publicat

her t river system slowly. These ecological criteria must be satisfied while iles creat is h

t simultaneously meeting independent constraints for flood control, navigation, L f

M of

and ot and sedimentation. The main engineering approaches were to divert flows to the X river's original course and its floodplain by blocking the C-38 canal with om yles, r f hydraulic structures such as weirs and earth plugs. Backfilling part of the canal st version was also considered. print posed

e The primary criterion for achieving environmental restoration goals is the h heading reestablishment of prechannelization hydrology. Key characteristics of recom

use t prechannelization hydrology were discussed in several papers presented at the Kissimmee River Symposium (Loftin et al., 1990). Critical hydrologic breaks, ease l been

P determinants of prechannelization ecological integrity were reduced to a form

word

has that could be used to compare alternative restoration plans. Key hydrologic ed.

hs, criteria are given below.

insert 1. Continuous flow with duration and variability comparable to

ally prechannelization records. Historical data indicate that continuous line lengt

original work discharge was a critical factor in the evolution and maintenance of e h t

biological communities in the prechannelization Kissimmee River ecosystem. Restoring the integrity of the Kissimmee River ecosystem he original; ion of

t depends on reestablishing the range of discharges of appropriate duration at o during representative (e.g., 10-year) postrestoration periods. Sheri et al. ue t r have been accident

y (1994) described the monthly discharge variations. The flow discharge t a characteristics thought to be necessary to restore biological communities represent m are

a that existed before channelization are (a) continuous flow from July errors

through October, (b) highest discharges in September through November and lowest flows in March through May, and (c) a wide range of

age breaks discharge variability. These features should maintain favorable levels of P is new digit h

pographic dissolved oxygen during summer and fall, provide nondisruptive flows for y iles. T t

e fish species during their spring reproductive period, and restore the ile: ng i f t temporal and spatial heterogeneity of river channel habitat. F

D 2. Average flow velocities between 0.24 and 0.55 meter per second (mps) P peset and som is y h t

ined, a bout A ret original t

ion. om

r when flows are contained within the river channel. Specifically, flow ibut f r t cannot velocities within 60 percent of river channel cross sections must not fall r at not

o below 0.24 mps for more than three consecutive days during July- f September and 10 consecutive days during October-June. These velocities

however, complement the discharge criteria by protecting river biota, because too version ng,

t little flow results in low concentrations of dissolved oxygen and excessive paper book, at ive flow could interfere with important biological functions (e.g., feeding and at rm o reproduction of fish). riginal horit ic f

o 3. Overbank flow along most of the floodplain when discharges exceed e h 40-57 cubic meters per second. This criterion reinforces and will t he aut t

om reestablish important physical, chemical, and biological interactions r as ing-specif t between the river and its floodplain. ion ed f 4. Slow flood recession rates. A flood recession rate of less than 0.3 meter peset y per month is required to restore the diversity and functional utility of publicat

her t floodplain/ wetlands, foster sustained river/floodplain interactions, and iles creat is h t

L f maintain river quality. Slow drainage is particularly important during

M of

and ot biologically significant periods, such as the nesting season for wading X birds. Rapid recession rates (e.g., rates that will drain most of the om yles, r f floodplain in less than a week) lead to fish kills and thus are not st version compatible with ecosystem restoration. print posed

e 5. Floodplain inundation frequencies comparable to prechannelization h heading hydrology, including seasonal and long-term variability characteristics. recom

use t Shen et al. (1994) shows the prechannelization inundation frequencies for the floodplain adjacent to the Fort Kissimmee gauging station and breaks, ease l been

P provides guidelines for this criterion. For example, during a representative

word

has 10-year period, November stages should inundate 100 percent of the ed.

hs, floodplain during 4 of the 10 years and 75 percent of the floodplain

insert during 7 of the 10 years. When the entire floodplain is inundated, depths

ally along the periphery of the floodplain should measure between 0.3 and 0.6 line lengt meter. These inundation levels will lead to redevelopment of floodplain original work e h

t structure and function and reestablish the floodplain as an integral component of the Kissimmee River ecosystem. Ecologically, the most he original;

ion of important features of stage criteria are water level fluctuations that lead to t at o seasonal wet-dry cycles along the Periphery of the floodplain, while the ue t r have been accident remainder (approximately 75 percent) of the floodplain is exposed to only y t a intermittent drying periods that vary in timing, duration, and spatial represent m are

l extent. As stated in Loftin et al. (1990, p. 26): a errors Reestablishment of ecological integrity requires that all restoration criteria are met simultaneously. A piecemeal restoration program in which some of the age breaks

P established restoration criteria are achieved in one segment of the system, and is new digit h pographic other criteria are met in another portion, will not accomplish restoration goals y iles. T t

e and may be of little or no value. Game fish populations, for example, may still ile: ng i f t be limited if appropriate flow characteristics are restored but production of F

D potential food resources on the floodplain is limited by inadequate inundation, P peset and som is

y or inaccessibility to river fish because levees or berms block the connectivity h t

(interaction) between the river and floodplain. Alternatively, restoration of ined, a bout A ret original t

ion. om

r floodplain inundation frequencies and the prechannelization stage-discharge ibut f r t

cannot relationship probably would not benefit game fish species unless enough flow r at not is reestablished to improve dissolved oxygen regimes in the river during o f summer and fall. Similarly, water level fluctuations in broadleaf marshes on the floodplain will be of no value to wading birds if reestablishment of however,

version peripheral wet prairie habitat is restricted or precluded by rapid stage recession ng,

i t

paper book, rates. at ive at rm o Three alternative restoration plans have been selected by the District for riginal horit ic f

o analysis. In the Fixed Weir Plan, 10 weirs would be installed along the canal to e h

t divert flows into the river oxbows adjacent to the weirs. In the Level I Backfill he aut t

om Plan, the same canal reaches in which weirs would be installed in the Weir Plan r as ing-specif t would be completely backfilled between the two junctions with the oxbows. In ion ed f

peset the Level II Backfill Plan a specific, long, continuous canal reach would be y backfilled. New river reaches would be created to maintain a continuous river publicat her t reach with the same canal backfill reach. iles creat is h t L f Fixed Weir Plan: The advantage of using weirs is their flexibility in M of

and ot operation. Gated weirs can be opened during floods to decrease the need for X flood levees or additional flooding fights. om yles, r f st version During high floods the oxbow flow velocities would be between 2 and 3 mps. These velocities would cause erosion and deposition of sediments in the print posed

e river oxbow reaches and could interrupt navigation. Channel maintenance h heading probably would be needed after major floods. recom

use t Approximately 40-50 percent of the oxbow length (revitalized river

breaks, channels) adjacent to the weirs would have flow velocities within the ease l been

P ecologically acceptable range of 0.24 to 0.55 mps. These oxbows were part of

word has

ed. the active river system before the construction of C-38 canal. However, many hs, more reaches would have velocities greater than 0.55 mps (with maxima on the

insert order of 1.5 mps) than below 0.24 mps. About 26 kilometers of banks

ally (revitalized river channels) would be inundated at flow discharges of 40 cubic line lengt

original work meters per second at the entrance of the river and 57 cubic meters per second at e h t the downstream end of the river. About half of this inundation length would

occur at oxbows. Several existing control structures in the river, together with he original; ion of

t their levees, can control the recession rates in the lower 40 percent of the pools. at o However, the stage recession rate after floods, in at least 60 percent of all upper ue t r have been accident reaches of pools, would far exceed 0.3 meter per month. These rates could even y t a reach 0.3 meter in a six-hour period. Complex flow operation schemes might be represent m are

a devised to control both inflows and outflows from each pool to reduce the

errors recession rate.

Level I Backfill Plan: For this plan, during high floods, the oxbow flow

age breaks velocities would vary between 1.5 and 2.1 mps. These velocities would cause P is new digit

h erosion and deposition in the oxbows. During normal flows, between 18 and 33 pographic y iles. T t

f percent of the oxbow velocities would be in the range of 0.24 to 0.55 mps. e ile: ng i f

t Except for periods of low flows, more flow velocities would be above 0.55 mps F

D (with maxima on the order of 1.5 mps) than below 0.24 mps. About 16 P peset and som is y kilometers of h t

ined, a bout A ret original t

ion. om

r banks (in revitalized river channels) would be inundated for flow discharges of ibut f r t cannot 40 cubic meters per second at the entrance of the river and 57 cubic meters per r at not

o second at the exit end of the river. All internal control structures together with f their levees can only control the recession for the bottom 40 percent of the

however, respective pools. At the upper 60 percent, the stage recession rate after floods version ng,

t would far exceed 0.3 meter per month. It is nearly impossible to design paper book, at ive complex flow operation schemes to control both inflows and outflows from at rm o each pool to reduce the recession rate because the capacity for flood flow under riginal horit ic f

o this plan would be greatly reduced by the earth plugs blocking the canal. The e h amount of time that given proportions of the floodplain would be inundated t he aut t under this plan is slightly less than would be inundated under the Fixed Weir om r as ing-specif t Plan, and these values are far from meeting the requirements for ecological ion ed f restoration. peset y Level II Backfill Plan: The Level II Backfill Plan should produce flow publicat

her t velocity ranges close to the ecological criteria if the future precipitation regime iles creat is h t

L f matches the precanal conditions and the flow regulation scheme can be properly

M of

and ot designed. Historical data suggest that the flow properties of the Kissimmee X River were similar in 1901 and 1958. In addition there was no detectable om yles, r f change in the river's course. During high floods, the oxbow flow velocities st version would vary between 1 and 1.3 mps and probably would not interrupt navigation. print posed

e During normal flows, in 40 to 52 percent of the lengths of the oxbows, the flow h heading velocities would be in the range from 0.24 to 0.55 mps, and in very few oxbows recom

use t would the velocities exceed 0.55 mps. The flow velocity in all oxbows would be below 0.76 mps. breaks, ease l been

P Upper lake level flood control capacity should be provided by leaving a

word

has portion of the Canal C-38 intact in the upper reach. Perhaps the best approach in ed.

hs, this plan is to completely backfill part of the river reach. This should satisfy the

insert flood criterion for Lake Kissimmee upstream from the Kissimmee River.

ally Sedimentation problems can be investigated with a careful monitoring system. line lengt If significant movement of sediment occurs, appropriate actions should be original work e h

t taken. Construction would be carried out in several stages over several years. The extent of backfilling would be governed by the amount of available he original;

ion of funding, available soil, the extent of the vegetation growth, and the possible t at o relaxation of the water level constraint at Lake Kissimmee during flooding. ue t r have been accident Field tests should be conducted at different times to monitor growth of y t a vegetation. Knowledge of vegetation growth should be useful both to protect represent m are

l against erosion and to analyze hydraulic resistance. The data collected in the a field during future years would determine the exact extent of backfilling. errors A certain amount of dredging in the oxbows may be needed. In the Level

age breaks II Backfill Plan, bank erosion and sediment deposition would be limited. Only a P is new digit

h small amount of maintenance dredging in the oxbows may be needed after pographic y iles. T t

f major flooding. e ile: ng i f It is recommended that one type of plan be selected by the District from the t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r three plans for final engineering design and construction analysis. Certain ibut f r t cannot detailed engineering analyses such as the extent and sequence of the backfilling, r at not

o as well as the number and location of earth plugs, or weirs, are still needed. The f possible effects of each tributary (slough) during flooding should also be

however, investigated. Currently sufficient data are not available to make these analyses. version ng,

t In accordance with the study team's recommendations, the state of Florida paper book, at ive has requested funding from the U.S. Congress. At the direction of Congress, the at rm o U.S. Army Corps of Engineers, Jacksonville District, has investigated the team's riginal horit ic f

o work and converted it into an engineering feasibility project, which is awaiting e h further federal funding. t he aut t

om r as ing-specif t ion

ed f Niobrara Whooping Crane Studies peset y The U.S. Bureau of Reclamation planned to construct a water supply dam publicat

her t on a braided section of the Niobrara River near Norden, Nebraska. The primary iles creat is h t

L f objective was to supply irrigation water for local farmers. This plan was

M of

and ot stopped by the courts after the U.S. Fish and Wildlife Service pointed out that X whooping cranes, an endangered species, stop at that reach of the Niobrara om yles, r f River during their migration seasons. I was asked to develop an engineering st version design compatible with the requirements of the cranes. Because there are only print posed

e about 100 whooping cranes, it is difficult to determine their ecological h heading requirements, but they are believed to be similar to those of the sandhill cranes. recom

use t Sandhill cranes prefer to rest on sandbars that are submerged by less than 0.2 meter of slow-flowing water amid vegetation shorter than 0.9 meter, and away breaks, ease l been

P from riverbanks. These conditions are required to enable the birds to forage and

word

has evade predators. Based on these requirements, we determined that the braided ed.

hs, feature (a river reach with multiple anastomosing channels) was critical to

insert provide shallow, vegetated sandbars at sufficient distance from the riverbanks.

ally We identified the flushing flow requirements necessary to maintain the line lengt braided stream. Certain portions of the stream below the proposed Norden Dam original work e h

t would be unavoidably changed from braided to meandering by the release of flows with relatively small amounts of sediment particles from the reservoir. he original;

ion of We planned to maintain the braided characteristic of the river farther t at o downstream by regulating the flow, controlling vegetation growth, and even ue t r have been accident breaking the ice jams that form annually. We reported our conclusions to both y t a the Bureau of Reclamation engineers and Fish and Wildlife Service biologists. represent m are

l After the conclusion of our study, we were pleased to learn that the Fish and a Wildlife Service agreed to withdraw its objection to the construction of the dam errors if the Bureau of Reclamation would follow our recommended flow release

age breaks plans. The Bureau of Reclamation agreed to follow our recommendations. In P is new digit

h the end the dam was never built because of a lack of funding. Like the pographic y iles. T t

Kissimmee Restoration Project, this study indicated that engineers and f e ile: ng i f biologists can work together, and engineers can provide plans to satisfy t F

D ecological needs. P peset and som is y h t

ined, a bout A ret original t

ion. om

r FUTURE NEEDS ibut f r t cannot These two cases demonstrate the need for integrated efforts between r at not o

f engineers and ecologists to enhance our river management. We should seek to increase communication, conferences, and joint research across various however,

version disciplines. Every effort should be made for river engineers and stream ng,

i t paper book, at ive ecologists to achieve a basic knowledge of each other's fields. at rm o riginal horit ic f

o REFERENCES e h t he aut Loftin, M. K., L. A. Toth, and J. T. B. Obeysekera. 1990. Kissimmee river restoration: Alternative t

om plan evaluation and preliminary design report. West Palm Beach, Fla.: South Florida r as ing-specif t Water Management District. ion ed f Shen, H. W., G. Q. Tabios III, and J. A. Harder. 1994. Kissimmee river restoration study. Journal of

peset Water Resources Planning and Management 120(3) (May/June):330-334. y World Commission on Environment and Development. 1987. Our Common Future. Oxford,

publicat England: Oxford University Press. her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

Copyright © National Academy of Sciences. All rights reserved. Engineering Within Ecological Constraints http://www.nap.edu/catalog/4919.html ''DO NO HARM'': A NEW PHILOSOPHY FOR RECONCILING ENGINEERING AND 187 ECOLOGY e h t be

ion. om r ibut f r t cannot r at not ''Do No Harm'': A New Philosophy for o f Reconciling Engineering and Ecology however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h David J. Schaeffer t he aut t

om r as ing-specif t THE UPPER MISSISSIPPI RIVER AND ILLINOIS ion ed f

peset WATERWAY SYSTEM y 1

publicat The Upper Mississippi River (UMR) and the Illinois Waterway (IWW) her t iles creat is

h are important shipping arteries comprising 1,250 navigable miles that drain t L f

M of 697,000 square miles (Figure 1). Between 1960 and 1990, commerce on the

and ot X UMR increased from 27 million to 91 million tons per year and IWW shipping om yles, r

f doubled to 46 million tons per year. This navigation system (UMR-IWWS) st version includes 37 lock sites and more than 360 terminals. The projected average

print annual growth in shipping is between 1.7 and 3.1 percent for the UMR and posed e h

heading between 1.2 and 2.5 percent for the IWW. However, most locks were designed

recom to accommodate only a small fraction of the current traffic, and their 600-foot use t length is half that of many of the tows (U.S. Army Corps of Engineers, 1991), breaks, ease l been which requires that the barges be unlashed and sent through in smaller groups. P To ensure adequate navigation capacity on the UMR-IWWS through 2050, word has ed.

hs, the U.S. Army Corps of Engineers proposes to spend several billion dollars renovating 27 locks on the UMR and 8 locks on the IWW. The proposed insert increases in navigation capacity are highly controversial. ally line lengt original work e h t OPPOSING PHILOSOPHIES

The controversy results from deep historical conflicts between the Corps he original; ion of t at o with its production-based philosophy and various federal, state, and

ue t nongovernmental organizations with conservation-based philosophies (Leopold, r have been accident y t

a 1949; Stone, 1974). The production-based philosophy is a short-term view (less represent m are

than a l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a FIGURE 1 Upper Mississippi River and Illinois Waterway navigation system. represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r century): the purpose of resources is be used to their fullest by humans, ibut f r t cannot with minimal regard to other users (i.e., species) or abiotic components of the r at not

o ecological system. The conservation-based philosophy, as discussed in this f paper, is a long-term view (centuries to millennia): the purpose of ecosystems is

however, to provide numerous biological and abiotic resources on a sustainable basis. version ng,

t (The production-based philosophy has dominated for two centuries the statutes paper book, at ive that govern resource use in the United States, but statutes are increasingly at rm o conservation-based.) riginal horit ic f

o While Chief of Engineers, General Henry J. Hatch brought these e h philosophies together when he declared the U.S. Army Corps of Engineers to be t he aut t

om the nation's environmental engineers. These philosophies are brought together r as ing-specif t in law by the National Environmental Policy Act (NEPA).2 Disagreement ion ed f regarding the appropriate philosophical balance in practice is at the heart of the peset y conflict between conservationist decision makers outside the Corps of publicat

her t Engineers and decision makers in the Corps. The former believe that the Corps iles creat is h

t is not considering all significant effects of river navigation on the ecological L f

M of

and ot systems. X Environmental management has a variety of objectives, including om yles, r f preservation, infrastructure maintenance, and biological diversity, and a variety st version of human uses, including income production, life support, recreation, and print posed

e aesthetics. Achieving these objectives over the long-term requires sustainability h heading of the underlying ecosystem (Costanza, in this volume; Costanza et al., 1992; recom

use t Cox et al., 1993b; Rapport et al., 1985; Schaeffer, 1991; Schaeffer et al., 1988). Progress depends on striking an appropriate balance among the various goals, breaks, ease l been

P using environmental resources efficiently and only to the extent necessary

word

has (Herricks et al., 1988; Schaeffer et al., 1985). Incomplete ecological knowledge, ed.

hs, or a balance weighted toward social perceptions that favor use, often results in

insert ecological disasters such as occurred in the Florida Everglades after hydraulic

ally modifications (Wodraska and yon Haam, in this volume). line lengt The conventional production-based philosophy is based in a legal system original work e h

t that legitimizes exploitation of the ecosystem to accomplish short-term human- oriented goals at the expense of long-term ecosystem sustainability (McNeely, he original;

ion of 1988). Because legislation is shaped by compromises among political, social, t at o and economic forces, the law presents multiple, fragmented, and uncoordinated ue t r have been accident objectives for environmental management (Schaeffer et al., 1980). Specifically, y t a the ecological goal of "sustainable" ecosystems is based on an emerging legal represent m are

l principle that the "right" of ecosystems to be sustainable is inherent (Stone, a 1974). Conservation agencies do not at present operate under statutes that grant errors sustainability as an inherent ecosystem right, but these agencies do implement

age breaks programs under statutes that regard sustainability as a goal. These statutes P is new digit

h include NEPA, the Endangered Species Act, and the ''health of the ecosystem'' pographic y iles. T t

requirement in the 1990 Clean Air Act Amendments. The 1972 Federal Water f e ile: ng i f Pollution Control Act established the goals that the nation's surface waters Were t F

D to be "fishable" and "swimmable." To achieve these goals required that standards P peset and som is y h t

ined, a bout A ret original t

ion. om

r be set for toxic effluents based on health effects (Section 307(a)(2)) and that ibut f r t cannot surface water criteria be established based on the identifiable effects of each r at not

o pollutant on the public health and welfare, aquatic life, and recreation (Section f 304(a)).

however, Both philosophies consider interrelationships between ecosystems and version ng,

t human legal, social, political, and economic systems. However, their emphasis paper book, at ive on dissimilar relationships results in fundamental differences between the two at rm o philosophy's valuations of ecosystem worth and protection. riginal horit ic f o e h t he aut

t Engineering Production Philosophy

om r as ing-specif t Engineers' production-based philosophy is supported by existing ion ed f legislation that subsumes economic, social, and political factors. Paradoxically, peset y although this philosophy generally increases the use of ecosystems for short- publicat

her t term human purposes (e.g., mining, lumbering), it has resulted in explicit and iles creat is h

t implicit protections for ecosystems. For example, the "fishable" goal of the L f

M of

and ot 1972 amendments to the Federal Water Pollution Control Act was (ostensibly) X environmental.3 However, a production-based philosophy dominated the EPA om yles, r f implementation regulations, which emphasized minimizing the danger to st version human health from consumption of contaminated water and aquatic organisms. print posed

e Generally, regulations developed using the production-based philosophy h heading emphasize particular known and knowable components of ecosystems, such as recom

use t specific "threatened" and "endangered" species, rather than the sustainability of an entire ecosystem. Although most regulations based on a production-based breaks, ease l been

P philosophy result in minimal legal protections to ensure ecosystem 4 word

has sustainability, some implicitly limit adverse effects on the unknowable ed.

hs, components of ecosystems, such as might result from climate changes and

insert pollutants. One example is evidence that the sexual abnormalities, feminization,

ally and marked declines in fertility and life span that are now being identified in line lengt many aquatic species of reptiles, fishes, and amphibians are due to binding of original work e h

t the estrogen receptor by pollutants present in the environment at levels defined in regulations as safe (Colborn et al., 1993; McLachlan, 1993). Though these he original;

ion of effects were previously unappreciated, their magnitudes may be limited by t at o existing regulations that were written in response to earlier understanding of ue t r have been accident effects of pollutants on reproductive systems. y t a The production-based philosophy also produces adverse consequences for represent m are

l management and protection efforts. Production-based goals make it difficult to a determine whether an effect is adverse, because regulations, management aims, errors and protection programs are developed from assumptions that are not fully

age breaks inclusive of the range of services provided by ecosystems. Some of these P is new digit

h assumptions are given below. pographic y iles. T t

e 1. Environmental management and protection efforts are based on "known" ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r science, with the presumption against adverse effects unless such effects ibut f r t cannot can be demonstrated. For example, it has been known (i.e., assumed) that r at not

o the discharge of very low concentrations of organic pollutants in waste f waters causes no harm. But recent declines in numerous aquatic and

however, amphibian species appear to be due to the estrogenic effects of low version ng,

t concentrations of highly potent compounds, for example, by binding to paper book, at ive the estrogen receptor. at rm o 2. Environmental management and protection efforts are presumed to be riginal horit ic f

o comprehensive when they are actually only minimal. For example, water e h use policies in the western states have increased crop yields but have also t he aut t

om continuously increased the salinity of the soil, destroyed the ecology of r as ing-specif t the Grand Canyon, and adversely altered rainfall patterns in the region ion ed f (Maranto, 1985; Poster, 1984). peset y 3. Environmental management and protection efforts are consumed by an publicat

her t inefficient process of administrative rule making and are perpetually open iles creat is h t

L f for challenge, review, and revision. For example, the U.S. Environmental

M of

and ot Protection Agency (USEPA) spent several years developing separate X regulations for the application of sewage sludge to agricultural and om yles, r f nonagricultural land, but changed its position at the last moment and st version promulgated a single standard (USEPA, 1993). print posed

e 4. Statutes and regulations emphasize single stress agents or individual h heading species and do not consider biological communities or, in the broad sense, recom

use t their abiotic habitat. For example, the Clean Water Act's goal of "fishable" was translated by the Environmental Protection Agency as breaks, ease l been

P water quality criteria to ensure that fish were "consumable" by humans.

word has ed. hs, Conservation Philosophy insert

ally The conservation-based philosophy is directed toward enhancing and line lengt sustaining the known, knowable, and unknowable components of an ecosystem. original work e h

t A suitable legal framework would define and balance human long-term needs for sustainable ecosystems against short-term uses of ecological resources he original;

ion of (McNeely, 1988). t at o Whereas the production-based philosophy uses multiple formulations of a ue t r have been accident sustainable ecosystem that depend on the proposed uses of resources, the y t a conservation-based philosophy uses features common to all sustainable represent m are

5 l ecosystems (Holling, in this volume; Odum, 1969; Rapport et al., 1985; a Schaeffer et al., 1988). Many of these characteristics are familiar to engineers errors because they concern a system's thermodynamic and kinetic properties,

age breaks including fluxes of energy and materials, regulation of fluxes through feedback P is new digit

h processes, and establishment of pseudoequilibria, such as the capacity of an pographic y iles. T t

ecosystem to temper toxic effects. Like engineered materials, ecosystems fail f e ile: ng i f when stresses exceed system limits (resistance failures), occur too frequently t F

D (resilience failures), or alter fundamental properties of the habitat (see Holling, P peset and som

is in this volume). Engineers y h t

ined, a bout A ret original t

ion. om

r need to increase their understanding of ecological function. With this ibut f r t cannot background, they can help ecologists develop standardized methods to measure r at not

o ecosystem resistance and resilience, and quantify ecosystem tolerance limits, f such as thresholds (Khan, 1992; Schaeffer and Cox, 1991).

however, Certain laws provide explicit protections for the known and knowable version ng,

t aspects of the domain encompassed in the term "ecosystem" in the conservation- paper book, at ive based philosophy. For example, the Endangered Species Act affords protection at rm o to the spotted owl by ensuring the sustainability of the old-growth forest that is riginal horit ic f

o its habitat. This implicitly also protects the unknowable relationships among the e h owl, other species, and abiotic habitat components. The Endangered Species t he aut t Act does not require balancing economic costs against the ecological benefits om r as ing-specif t resulting from protection of a species. If the Endangered Species Act is an ion ed f idealistic implementation of the conservation-based philosophy, the National peset y Environmental Policy Act requires a pragmatic balancing of the production- publicat

her t based and conservation-based philosophies. Thus, if threatened and endangered iles creat is h

t species are not at risk, the National Environmental Policy Act will allow for an L f

M of

and ot ecosystem to be exploited for some purposes, provided that efforts are made to X avoid, minimize, or mitigate effects on other ecosystem components. om yles, r f st version UPPER MISSISSIPPI RIVER NAVIGATION STUDIES print posed e h heading The UMR-IWW navigation system provides habitat for at least 485 species recom

use t of birds, mammals, amphibians, reptiles, and fish, including many endangered or threatened species. It includes a national fish and wildlife refuge of more breaks, ease l been

P than 226,650 acres and provides drinking water, irrigation, and recreation

word

has services to hundreds of communities. To ensure that the natural resources and ed.

hs, other services are not adversely affected by increases in barge traffic and the

insert associated engineering efforts, the Corps has embarked on a $42 million

ally program to assess the effects from increased navigation and recreational traffic. line lengt These studies will result in the preparation of a final environmental impact original work e h

t statement in 1999 by the Corps, with advice from state and federal natural resource agencies (U.S. Fish and Wildlife Service, U.S. Environmental he original;

ion of Protection Agency, Illinois Department of Conservation, Iowa Department of t at o Natural Resources, Minnesota Department of Natural Resources, Missouri ue t r have been accident Department of Conservation, and Wisconsin Department of Natural Resources) y t a and other organizations that can influence legal acceptability through the Courts represent m are

l (e.g., Izaak Walton League, Sierra Club, and Minnesota-Wisconsin Boundary a Area Commission). However, the differences in the perspectives and goals of errors these various agencies, the Corps, and other organizations have resulted in a

age breaks decade-long conflict in setting the goals for the ecological studies (Schaeffer et P is new digit

h al., 1992; U.S. Army Corps of Engineers, 1991). As discussed below, the pographic y iles. T t

conflict reflects a clash of philosophies. f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r ASSESSING FUTURE EFFECTS: A CLASH OF PHILOSOPHIES ibut f r t cannot In response to requirements of the National Environmental Policy Act, the r at not o

f Corps is carrying out engineering and ecological studies to determine whether incremental increases in navigation traffic will cause significant, incremental, however,

version detrimental changes in ecological resources. Site-specific studies will be ng,

i t paper book, at ive completed as structures are scheduled for renovation. The ecological studies at rm will provide data the Corps needs to devise management plans for maintaining o riginal horit

ic f the best possible ecosystem conditions without constraining navigation. Thus, o

e regarding the construction of the second lock at the Melvin Price Locks and h t he aut

t Dam, an interagency team reported as follows:

om r as ing-specif t When [this study] was initiated, the objective was focused towards pursuing ion ed f investigations which would identify and quantify impacts associated with the peset y incremental traffic increase resulting from the second lock. However, publicat

her t recognizing that the basic study elements needed for this investigation will also iles creat is

h be useful to future Corps studies that will require navigation impact t L f

M of information, the following ... objective was adopted by the interagency team:

and ot X om yles,

r The [Corps] will develop studies which identify and quantify navigation f st version traffic impacts to significant [UMR-IWW] natural resources where such impacts are currently poorly defined due to lack of scientific data. If possible, print posed e

h studies will quantify the impacts associated with that increment of traffic caused heading by the second lock. Where feasible , studies will quantify secondary impacts recom use t (U.S. Army Corps of Engineers, 1991, p. 3; emphasis added). breaks,

ease In 1990 when this study plan was written, the Corps and representatives of l been P the resource agencies had reached an accommodation that would allow the word has ed. Corps to minimize the harm to the ecological system and satisfy demands for hs, barge traffic capacity. Unfortunately, by the time the ecological studies were insert initiated in 1994, all the organizations had new representatives, who resurfaced ally

line lengt the old conflicts that again polarized the philosophies. The problems appear to original work

e fall into three broad areas: personal beliefs that are not separated from agency h t

policy (possibly because of the absence of enunciated policy); the Corps' focus on incremental effects and resource agencies' focus on total effects; and he original; ion of t

at differences in reliance on mathematical models. Thus, the Corps' field and o laboratory studies and mathematical models suggest that the effects will be ue t r have been accident y t small, possibly not measurable, and not ecologically significant. However, the a represent m

are conclusions drawn by the Corps were rejected by most resource agency

l a representatives, who instead have concluded from general ecological errors considerations and field observations (e.g., habitat loss) that the effects will be significant and adverse. They want the Corps to provide absolute assurances age breaks

P that no harm will result from increases in navigation traffic. is new digit h pographic

y The resource agency representatives have several beliefs stemming from iles. T t

f e

ile: their conservation-based philosophy. One belief is that the Corps must ng i f t

F determine whether the total effect on ecological resources from all traffic will D be appreciable, P peset and som is y h t

ined, a bout A ret original t

ion. om

r rather than limit the evaluation to the significance of incremental effects from ibut f r t cannot additional traffic. Another belief is that the Corps should gather basic scientific r at not

o and ecological data, even if such data cannot be used as a baseline for f determining whether significant impacts occur or for the "avoid, minimize,

however, mitigate" analyses the Corps has included in the environmental impact version ng,

t statement. The resource agencies' most important belief is that current traffic is paper book, at ive already causing deleterious effects, so additional ecological effects due to at rm o increases in traffic can not be minimal. The resource agency representatives riginal horit ic f

o anticipate that engineering studies the Corps is carrying out using a 400-foot- e h long 1:25 scale model of the Mississippi River and barges will result in major t he aut t revisions to the hydrodynamic and hydraulic models the Corps uses to estimate om r as ing-specif t environmental effects (due to shear forces and sediment resuspension) from ion ed f tows. The revised models would then confirm resource agency beliefs that peset y increases in navigation traffic will cause significant adverse ecological effects. publicat

her t In contrast, most engineers expect small changes in model coefficients, iles creat is h

t confirming that forces, wave action, and sediment transport due to tows will be L f

M of

and ot below ecologically relevant levels. Whatever balances are agreed to, all parties X recognize that engineering changes must meet the navigation needs of society om yles, r f without compromising the ability of future generations to meet their own st version ecological needs. print posed e h heading CONCLUSION recom use t In October 1994 the Cousteau society presented a "Bill of Rights for breaks, ease l been

P Future Generations" to the United Nations General Assembly. Articles 2 and 3

word

has state: ed. hs, Each generation ... has a duty as trustee for future generations to prevent insert irreversible and irreparable harm to life on Earth.... ally

line lengt It is, therefore, the paramount responsibility of each generation to maintain a original work

e constantly vigilant and prudential assessment of technological disturbances and h t

modifications adversely affecting life on Earth, the balance of nature, and the evolution of mankind in order to protect the rights of future generations. he original; ion of t at o Engineering profoundly affects the structure of life on Earth, so the ue t r have been accident engineers' ethic in carrying out technological modifications must be to "do no y t a harm" to the environment. Thus, engineers cannot continue to develop and represent m are

l implement technology as if it occurred in a thermodynamically isolated system. a Technological development takes place in an engineered system that has errors complex connections to multiple physical, chemical, biological, ecological, and

age breaks social systems. P is new digit

h An environmental ethic can be included in engineering if production goals pographic y iles. T t

f are defined within a conservation-based philosophy. This philosophic expansion e ile: ng i f can be summarized as a pair of goals: t F D

P to maximize engineering to maximize ecosystem sustainability peset and som is y h

t to maximize engineering by maximizing ecosystem sustainability

ined, a bout A ret original t

ion. om

r Effecting a change in philosophy to ensure the sustainability of ecosystems ibut f r t cannot will require education, research, and changes in law. r at not o f NOTES however, version ng,

i t

paper book, 1. The Upper Mississippi River extends from River Mile (RM) 218.0 near St. Louis, Missouri, at ive at

rm to RM 854.0 at Upper St. Anthony Falls Lock in Minneapolis-St. Paul, Minnesota. The Illinois o Waterway extends from Grafton to Chicago, Illinois. The total Illinois and Mississippi River riginal horit ic f

o navigation system contains 37 locks (of which 35 are included in the proposed renovation e

h program of the U.S. Army Corps of Engineers) and 360 terminals. Lock and Dam 26 (RM t he aut t

202.9, Alton, Illinois) was replaced in 1989 by the Melvin Price Locks and Dam (RM 200.8); a om r as ing-specif second lock opened in 1994. t

ion 2. The National Environmental Policy Act (NEPA) was passed by Congress in 1969 in part to ed f

peset integrate environmental considerations into the decision making process for "every y recommendation or report on proposals for legislation and other major federal actions

publicat significantly affecting the quality of the human environment" (§102[2][c]). NEPA put in place her t iles creat is

h the requirement for impact analyses that have evolved from limited assessments that meet the t L f letter of the law to comprehensive assessment programs that meet the spirit of the law. The role M of

and ot

X of NEPA in ensuring that the proposed changes in the UMR-IWW navigation capacity meet the spirit of the law has been discussed elsewhere (Cox et al., 1993a; Schaeffer et al., 1988, 1993). om yles, r f

st 3. Before 1972 the Federal Water Pollution Control Act (FWPCA) left it up to the states to version develop ambient water quality standards to protect interstate and navigable waters for uses the print

posed state wanted to facilitate (e.g., agriculture, industry, recreation, human consumption, prevention e

h of imminent health hazard). The 1972 amendments established a system of national standards, heading permits, and enforcement "goals" of "fishable and swimmable" waters by 1983 and total recom

use t elimination of pollutant discharges into navigable waters by 1985. Following amendment of the

breaks, FWPCA in 1977, it was designated the Clean Water Act. ease l been

P 4. Factors that alter an ecosystem from the conceptual image of that ecosystem embodied in a

word particular law (e.g., "fishable and swimmable") pose excess risk. The term de minimis risk is has ed.

hs, widely used in federal risk analysis (see Whipple, 1987) to mean a specific level below which a risk estimate is so small that it can be ignored i.e., a threshold (Schaeffer and Cox, 1991). A insert legal threshold for sustainability is the level of risk a given law accepts; for example, a game

ally fish with a sustainable population but which is not edible due to contamination. An ecological line lengt threshold is the value of a relevant ecological parameter at the point at which the risk becomes original work e

h adverse. For example, based on Karr's (1981) Index of Biotic Integrity, Khan (1992) found that t the quality of Illinois fisheries usually was less than "good" if there were fewer than 17 species. 5. These include habitat for desired diversity and reproduction of organisms; phenotypic and he original; ion of t genotypic diversity among the organisms; a robust food chain supporting the desired biota; an at o adequate nutrient pool for desired organisms; adequate nutrient cycling to perpetuate the ue t r have been accident ecosystem; adequate energy flux for maintaining the trophic structure; feedback mechanisms y t a for damping undesirable oscillations; capacity to temper toxic effects, including the capacity to represent m are

l decompose, transfer, chelate or bind anthropogenic inputs to a degree that they are no longer a toxic within the system. errors

age breaks REFERENCES P is new digit h

pographic Colborn, T., F. S. vom Saal, and A. M. Soto. 1993. Developmental effects of endocrine-disrupting y iles. T t

f chemicals in wildlife and humans. Environmental Health Perspectives 101:378-384. e ile:

ng Costanza, R., B. G. Norton, and B. D. Haskell, eds. 1992. Ecosystem Health: New Goals for i f t F Environmental Management. Washington, D.C.: Island Press. D P peset and som is y h t

ined, a bout A ret original t

ion.

om Cox, D. K., T. M. Keevin, F. T. Norris, S. Gensler, and D. J. Schaeffer. 1993a. When is a cost r ibut f r "exorbitant" under NEPA? The Environmental Professional 15:145-149. t cannot Cox, D. K., V. R. Beasley, and P. W. Andrews. 1993b. Balancing management goals for ecological r at not

o systems on a sustainable basis: An analysis of the Pacific Northwest timber dispute. The f George Wright Forum 10(4):76-81. Herricks, E. E., D. J. Schaeffer, and J. A. Perry. 1988. Biomonitoring: Closing the loop in the however, environmental sciences. Pp. 351-366 in Environmental Biology, S. Levin, ed. New York: version ng,

t Springer-Verlag. paper book, at ive Karr, J. R. 1981. Assessment of biotic integrity using fish communities. Fisheries 6:21-27. at rm Khan, S. 1992. Development of practical ecosystem threshold criteria using fisheries and benthic o

riginal data. M.S. Thesis. Champaign: School of Life Sciences, University of Illinois. horit ic f

o Leopold, A. 1949. A Sand County Almanac and Sketches Here and There. London: Oxford e

h University Press. t he aut t

Maranto, G. 1985. A once and future desert (Salinization of California farmland). Discover 6 om r

as (June):32-33. ing-specif t McLachlan, J. A. 1993. Functional toxicology: A new approach to detect biologically active ion ed f xenobiotics. Environmental Health Perspectives 101:386-387. peset

y McNeely, J. A. 1988. Economics and Biological Diversity: Developing and Using Economic Incentives to Conserve Biological Resources. Gland, Switzerland: International Union for publicat

her t Conservation of Nature and Natural Resources. iles creat is

h Odum, E. P. 1969. The strategy of ecosystem development. Science 164:262-270. t L f Poster, S. 1984. Halting land degradation. Focus 39(Spring):5-12. M of

and ot

X Rapport, D. J., H. A. Reiger, and T. C. Hutchinson. 1985. Ecosystem behavior under stress. American Naturalist 125:617-640. om yles, r f Schaeffer, D. J. 1991. A toxicological perspective on ecosystem characteristics to track sustainable st version development. Ecotoxicology and Environmental Safety 22:225-239. Schaeffer, D. J., and D. K. Cox. 1991. Approaches to establish ecosystem threshold criteria. Pp. print posed

e 157-169 in Ecosystem Health: New Goals for Environmental Management, R. Costanza, h

heading B. G. Norton, and B. D. Haskell, eds. Washington, D.C.: Island Press.

recom Schaeffer, D. J., J. Park, H. W. Kerster, and K. G. Janardan. 1980. Sampling and the regulatory

use t maze in the United States. Environmental Management 4:469-481.

breaks, Schaeffer, D. J., J. A. Perry, H. W. Kerster, and D. K. Cox. 1985. The environmental audit. I. ease l been Concepts. Environmental Management 9:191-198. P Schaeffer, D. J., E. E. Herricks, and H. W. Kerster. 1988. Ecosystem health. I. Measuring ecosystem word has ed. health. Environmental Management 12:445-455. hs, Schaeffer, D. J., D. E. Leake, T. M. Keevin, and E. E. Herricks. 1992. Development of a Plan of

insert Study (POS) to evaluate the biological risk of increased navigation traffic on the Mississippi River. The Environmental Professional 14:248-256. ally Schaeffer, D. J. D. K. Cox, E. E. Herricks, and T. M. Keevin. 1993. The design of NEPA studies: line lengt

original work Application of the study design assurance process to the Upper Mississippi River e

h navigation impact studies. The Environmental Professional 15:89-94. t Stone, C. D. 1974. Should Trees Have Standing? Toward Legal Rights for Natural Objects. Los Altos, Calif.: William Kaufmann. he original;

ion of U.S. Army Corps of Engineers. 1991. Plan of Study. Navigation Effects of the Second Lock Melvin t at o Price Locks and Dam. St. Louis, Mo.: St. Louis District Corps of Engineers. U.S. Environmental Protection Agency. 1993. Standards for the use or disposal of sewage sludge. ue t r have been accident y

t Federal Register (13 February 1993) 58:9248-9415. a Whipple, C., ed. 1987. De Minimis Risk. New York: Plenum Press. represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not Biographical Data o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e

h JOHN CAIRNS, JR., is University Distinguished Professor of t he aut t

Environmental Biology at Virginia Polytechnic Institute and State University. om r as ing-specif

t He was curator of limnology at the Academy of Natural Sciences of ion ed f Philadelphia for 18 years and has taught at various universities and field peset

y stations. He is a member of the National Academy of Sciences, a fellow of the

publicat American Academy of Arts and Sciences and the American Association for the her t iles creat is

h Advancement of Science, and a foreign member of the Linnean Society of t L f

M of London. He has received the Founder's Award of the Society for Environmental

and ot X Toxicology and Chemistry, the United Nations Environment Program Medal, om yles, r

f and a U.S. Presidential Commendation for Environmental Activities. Cairns has st version served as both vice president and president of the American Microscopical

print Society, has served on 17 National Research Council committees, two as chair, posed e h

heading currently serves on 14 editorial boards, and has served on the science advisory

recom boards of the International Joint Commission (U.S. and Canada) and the U.S. use t Environmental Protection Agency. The most recent of his 48 books are breaks, ease l been Restoration of Aquatic Ecosystems (committee chair), National Academy Press, P 1992; Environmental Literacy and Beyond, 1993; Implementing Integrated word has ed.

hs, Environmental Management, 1994; Ecological Toxicity Testing: Scale Complexity and Relevance, 1995; Rehabilitating Damaged Ecosystems, Second insert Edition, 1995; and Handbook of Ecotoxicology, 1995. Cairns holds a Ph.D. ally

line lengt degree in zoology from the University of Pennsylvania. original work

e DILWORTH W. CHAMBERLAIN is a senior consultant on h t environmental protection in the Environment, Health, and Safety Department at ARCO headquarters in Los Angeles, California, with more than 20 years of he original; ion of t at o experience in this ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r type of work. His responsibilities are to support all levels of management and ibut f r t cannot operations in ARCO as a technical consultant in the areas of environmental r at not

o impact assessment, oil spill response, environmental fate and effects of oil, f habitat restoration, and endangered species concerns. His geographic work

however, areas have included the continental United States, Alaska, South America, version ng,

t Europe, and Asia. His undergraduate degree is in zoology from California State paper book, at ive University, Los Angeles, and he holds a Ph.D. degree in biology from the at rm o University of Southern California. He is a member of the American Association riginal horit ic f

o for the Advancement of Science, Sigma Xi, the Society for Ecological e h Restoration, and the Southern California Academy of Sciences. t he aut t

om ROBERT COSTANZA is director of the Maryland International Institute r as ing-specif t for Ecological Economics, and professor in the Center for Environmental and ion ed f Estuarine Studies at the University of Maryland. Before joining the University peset y of Maryland, Costanza held positions at Louisiana State University and the publicat

her t Illinois Natural History Survey. Costanza's research has been focused on the iles creat is h

t interface between ecological and economic systems, particularly at larger L f

M of

and ot temporal and spatial scales. This includes landscape level simulation modeling, X analysis of energy flows, valuation of ecosystem services, and analysis of om yles, r f incentive systems. He is chief editor of Ecological Economics and is a member st version of the editorial boards of Ecological Modeling, Ecological Engineering, Trends print posed

e in Ecology and Evolution, and Ecological Applications. Costanza has received h heading numerous awards for his professional accomplishments, including the recom

use t Distinguished Achievement Award from the Society for Conservation Biology. He is a member of several national panels, including the National Research breaks, ease l been

P Council Panel on Economics of Biodiversity. Costanza has organized and

word

has chaired several professional meetings, authored more than 170 publications, and ed.

hs, edited three books, including Ecosystem Health: New Goals for Environmental

insert Management, Island Press (with B. Norton and B. J. Haskell). Costanza holds a

ally Ph.D. degree in systems ecology and environmental engineering from the line lengt University of Florida. original work e h

t ROBERT A. FROSCH is a senior research fellow at the John F. Kennedy School of Government, Harvard University. He recently retired from the he original;

ion of position of vice-president in charge of General Motors Research Laboratories. t at o Frosch's career combines varied research and administrative experience in ue t r have been accident industry and government service. He has been involved in global environmental y t a research and policy issues at both the national and the international level. From represent m are

l 1951 to 1963 he was employed at the Hudson Laboratories of Columbia a University, first as a research scientist and then as director from 1956 to 1963. errors In 1963 he became director for nuclear test detection in the Advanced Research

age breaks Projects Agency (ARPA) of the Department of Defense, and deputy director of P is new digit

h ARPA in 1965. In 1966 he was appointed assistant secretary of the Navy for pographic y iles. T t

research and development. He served in this position until January 1973, when f e ile: ng i f he became assistant t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r executive director of the United Nations Environment Program. In 1975 he ibut f r t cannot became associate director for applied oceanography at the Woods Hole r at not

o Oceanographic Institution, and from 1977 to 1981 he served as administrator of f the National Aeronautics and Space Administration. He served as president of

however, the American Association of Engineering Societies from 1981 to 1982. Frosch version ng,

t is a member of the National Academy of Engineering. He holds a Ph.D. degree paper book, at ive in theoretical physics from Columbia University. at rm o ROBERT HERMAN is L. P. Gilvin Centennial Professor, Emeritus, in riginal horit ic f

o Civil Engineering and sometime professor of physics at the University of Texas e h at Austin. Herman was previously with the General Motors Research t he aut t

om Laboratories, where he headed the Department of Theoretical Physics and the r as ing-specif t Traffic Science Department. Herman's research has included molecular and ion ed f solid-state physics, high-energy electron scattering, astrophysics and peset y cosmology, and operations research, especially vehicular traffic science and publicat

her t transportation. With Ralph Alpher in 1948, Herman made the first theoretical iles creat is h

t prediction that the universe should now be filled with a cosmic microwave L f

M of

and ot background radiation, which is key evidence for the validity of the Big Bang X model of the origin of the universe. Awards to Herman include the 1993 Henry om yles, r f Draper Medal of the National Academy of Sciences, the Magellanic Premium st version of the American Philosophical Society (1975), and the John Price Wetherell print posed

e Medal of the Franklin Institute (1980). Herman is a member of the National h heading Academy of Engineering, the American Academy of Arts and Sciences, and Phi recom

use t Beta Kappa. He holds a Ph.D. degree in physics from Princeton University. CRAWFORD (BUZZ) HOLLING occupies the Arthur R. Marshall, Jr., breaks, ease l been

P Chair in Ecological Sciences at the University of Florida. He worked for some

word

has years in the laboratories of the Department of the Environment, Government of ed.

hs, Canada, emphasizing research on mathematical and experimental analysis of

insert ecological processes, particularly predator/prey dynamics. Since then, he has

ally been, at various times, professor and director of the Institute of Resource line lengt Ecology, University of British Columbia, Vancouver, Canada, and director of original work e h

t the International Institute for Applied Systems Analysis, Vienna, Austria. His research has emphasized theoretical and applied aspects of ecological systems he original;

ion of and processes, and ecological policy and adaptive environment assessment and t at o management. Holling is currently performing a comparative study of the ue t r have been accident structure and dynamics of ecosystems based largely on boreal forests and the y t a Everglades. The key scientific question is how these systems are organized represent m are

l across scales from centimeters to hundreds of kilometers in space and from a months to millennia in time. The key policy question is how these systems errors might respond to global climate change. Holling is a fellow of the Royal

age breaks Society of Canada and has been awarded the Austrian Cross of Honour for Arts P is new digit

h and Science. He holds a Ph.D. degree in ecology from the University of British pographic y iles. T t

Columbia. f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r JAMES R. KARR is professor of fisheries, environmental health, and ibut f r t cannot public affairs at the University of Washington (Seattle). Before joining the r at not

o University of Washington, Karr held faculty positions at Purdue University, the f University of Illinois, and Virginia Polytechnic Institute. He has also served as

however, deputy director and acting director of the Smithsonian Tropical Research version ng,

t Institute. His research concentrates on areas such as tropical forest ecology, paper book, at ive stream ecology, water quality, watershed management, conservation biology, at rm o and environmental policy. Karr has served as a consultant on water resources riginal horit ic f

o and development to the Organization of American States and the South Florida e h Water Management District. In addition, he developed the Index of Biotic t he aut t Integrity, a biologically based method for evaluating the quality of water om r as ing-specif t resources. That index is now widely used throughout the world. Karr holds a ion ed f Ph.D. degree in zoology from the University of Illinois. peset y JUNE LINDSTEDT-SIVA is manager of environmental protection in the publicat

her t corporate Environment, Health, and Safety Department at ARCO headquarters iles creat is h t

L f in Los Angeles. Her group advises the corporation on environmental issues,

M of

and ot serves as consultants to management and operating companies, and participates X in environmental research. Lindstedt-Siva specializes in environmental planning om yles, r f and management and has done extensive work on oil spills, including the st version impacts of oil and spill cleanup on the environment and spill response planning print posed

e to minimize ecological impacts. She chaired the 1989 Oil Spill Conference, h heading which attracted more than 1,000 attendees from 31 countries. She also chaired recom

use t the American Petroleum Institute Oil Spills Advisory Group and works with the Marine Spill Response Corporation as an adviser to their R&D program. breaks, ease l been

P Lindstedt-Siva served on the National Science Board and the EPA Science

word

has Advisory Board panels on environmental risk reduction and bioremediation as a ed.

hs, spill cleanup method. She serves on the National Academy of Sciences Polar

insert Research Board. She has published many articles on oil spills and

ally environmental planning and management, and is a fellow of the American line lengt Association for the Advancement of Science, ASTM, and the Southern original work e h

t California Academy of Sciences. Lindstedt-Siva holds a Ph.D. degree in marine biology from the University of Southern California. he original;

ion of WILLIAM J. MITSCH is professor of natural resources and t at o environmental science and holds a joint appointment in the Department of Civil ue t r have been accident Engineering at the Ohio State University. His research and graduate teaching y t a have focused on wetland ecology and biogeochemistry, wetland creation and represent m are

l restoration, and ecosystem modeling. He is founder and editor-in-chief of a Ecological Engineering -The Journal of Ecotechnology . He has published errors some 150 papers on ecological matters and has edited or written eight books,

age breaks including Wetlands, 2nd ed. (Van Nostrand Reinhold, 1993) and Global P is new digit

h Wetlands - Old World and New (Elsevier, 1994). Mitsch is a frequent adviser to pographic y iles. T t

state and federal governments on wetlands f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r and has served on both the U.S. National Committee for the Scientific ibut f r t cannot Committee on Problems of the Environment (SCOPE) and the Wetland r at not

o Characterization Committee of the National Research Council. He currently is f president-elect of the Society of Wetland Scientists and chairs a SCOPE Project

however, on Ecological Engineering and Ecosystem Restoration. He is certified as a version ng,

t senior ecologist by the Ecological Society of America and as a professional paper book, at ive wetland scientist by the Society of Wetland Scientists. Mitsch received his at rm o Ph.D. degree in environmental engineering sciences from the University of riginal horit ic f

o Florida. e h BRYAN G. NORTON is professor of philosophy of science and t he aut t

om technology in the School of Public Policy, Georgia Institute of Technology. He r as ing-specif t writes on intergenerational equity and sustainability theory, with special ion ed f emphasis on biodiversity and ecosystem characteristics. His current research peset y includes work on methods of evaluation for intergenerational impacts publicat

her t (sponsored by the U.S. Environmental Protection Agency [EPA]). He is author iles creat is h

t of Toward Unity Among Environmentalists (Oxford University Press, 1991) and L f

M of

and ot coeditor of Ecosystem Health: New Goals for Environmental Management X (Island Press, 1992). He is especially interested in developing physical, om yles, r f ecosystem-level measures of health/ illness and relating these to human welfare. st version Norton has served on numerous panels, including the Ecosystem Valuation print posed

e Forum, the Risk Assessment Forum (EPA), and the Environmental Economics h heading Advisory Committee of the EPA Science Advisory Board. He is a fellow of the recom

use t Hastings Center. Norton holds a Ph.D. degree in philosophy from the University of Michigan. breaks, ease l been

P PAUL G. RISSER is president of Miami University, Oxford, Ohio. His

word

has research interests include the study of the structure and function of grassland ed.

hs, and forest ecosystems, environmental planning and management, and landscape

insert ecology and global change; he has published extensively. Risser currently

ally chairs the National Research Council Board on Environmental Studies and line lengt Toxicology and has served on a variety of committees of the National Research original work e h

t Council. He is past president of both the American Institute of Biological Sciences and the Ecological Society of America and is currently the secretary he original;

ion of general of the international Scientific Committee on Problems of the t at o Environment. Risser holds a Ph.D. degree in botany and soils from the ue t r have been accident University of Wisconsin. y t a DAVID J. SCHAEFFER is associate professor in the Department of represent m are

l Veterinary Biosciences at the University of Illinois. Before joining the a University of Illinois, Schaeffer served for 12 years as science adviser and chief errors of toxicology and statistics at the Illinois Environmental Protection Agency.

age breaks Schaeffer's interests are in toxicology, statistical modeling, bioassay P is new digit

h development, and theoretical and conceptual aspects of ecosystem ''health.'' He pographic y iles. T t

f has published numerous papers on these topics. Schaeffer holds a Ph.D. degree e ile: ng i f in organic chemistry from the City University of New York. t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r PETER C. SCHULZE is assistant professor of biology, Austin College, ibut f r t cannot Sherman, Texas. Before joining the faculty of Austin College, Schulze held a r at not

o research postdoctoral appointment at Lehigh University and taught at f Dartmouth College and Harvard University. Most recently he was the

however, 1993-1994 J. Herbert Hollomon Fellow of the National Academy of version ng,

t Engineering. Schulze's primary interests are the ecology of freshwaters and paper book, at ive human environmental impacts. Schulze holds a Ph.D. degree in biology from at rm o Dartmouth College and has been recognized by Harvard University for riginal horit ic f

o distinction in teaching. e h HSIEH WEN SHEN is professor of civil engineering at the University of t he aut t

om California, Berkeley. He was previously Professor in Charge of the Hydrology r as ing-specif t and Water Resources Program at Colorado State University. A primary research ion ed f effort by Shen is devoted to developing systems for releasing water from peset y reservoirs that satisfy ecological requirements of downstream biological publicat

her t communities. A present focus of this research is the Kissimmee River of iles creat is h

t Florida. Shen has advised the World Bank, the Inter-American Development L f

M of

and ot Bank, and the Governments of Argentina, Brazil, China, Colombia, the X Dominican Republic, Egypt, Honduras, Jamaica, New Zealand, Pakistan, om yles, r f Venezuela, and others. He received the Joan Hodges Queneau Award for st version outstanding engineering achievement in Environmental Conservation from the print posed

e National Audubon Society and the American Association of Engineering h heading Societies, the H. A. Einstein Award for significant contributions to waterway recom

use t management from the American Society of Civil Engineers, the Horton Award from the American Geophysical Union for significant contribution to breaks, ease l been

P hydrology, and a variety of other awards and recognitions. He is a member of

word

has the National Academy of Engineering. Shen holds a Ph.D. degree in civil ed.

hs, engineering from the University of California, Berkeley.

insert LOU C. SOILEAU IV is development manager, ARCO Oriente Inc.

ally Soileau is responsible for the planning and execution of the Villano Field line lengt development program as well as for the overall management of ARCO's original work e h

t activities in Ecuador. He is a registered professional petroleum engineer with more than 23 years of experience throughout the United States and the North he original;

ion of Sea. Soileau has helped ARCO reduce costs and increase operating and t at o hydrocarbon recovery efficiency through the application of innovative concepts, ue t r have been accident including unmanned remote offshore platforms, enhanced oil recovery methods, y t a and nearshore oil field development using long-reach directional drilling, and represent m are

l subsea gas field development. He is a member of the Society of Petroleum a Engineers and a graduate of Louisiana State University. errors PETER E. VON HAAM works in the Bay/Delta Branch of the

age breaks Metropolitan Water District of Southern California. He previously served on the P is new digit

h staff of the California Legislature, Assembly Committee on Water, Parks, and pographic y iles. T t

f Wildlife. Von Haam holds a bachelor's degree from the University of e ile: ng i f California, Berkeley, in t F D P peset and som is y h t

ined, a bout A ret original t

ion. om

r political economy of natural resources and a law degree from the University of ibut f r t cannot Washington (Seattle). He has been admitted to the California State Bar. r at not

o JOHN R. WODRASKA is general manager of the Metropolitan Water f District of Southern California, which provides water to nearly 16 million

however, residents. Before that, Wodraska served as executive director of the South version ng,

t Florida Water Management District, where he was closely involved with the paper book, at ive Everglades controversy. He holds a bachelor's degree from Wilkes College in at rm o Pennsylvania in business and finance, and a master's degree in geography from riginal horit ic f

o Columbia University. e h MARTIN L. WOUCH is senior environmental engineer in the t he aut t

om Environment, Health, and Safety section at ARCO International Oil and Gas r as ing-specif t Company in Plano, Texas. He is responsible for developing and implementing ion ed f environmental protection and compliance programs for ARCO's international peset y oil and gas subsidiaries. He has been involved both in the planning and in the publicat

her t field for the ARCO project in Ecuador. His undergraduate degree is in earth iles creat is h

t science (geological concentration) from Pennsylvania State University, and he L f

M of

and ot holds a master's degree in environmental engineering from Louisiana State X University. He is also a registered professional engineer in the state of Louisiana. om yles, r f ALBERT H. WURTH, JR., is associate professor of government, Lehigh st version University. His field of interest is public policy and political economy, with a print posed

e focus on politics of the environment, technology, and information. He has h heading published numerous articles in these fields. His present focus is on recycling recom

use t and waste reduction. Wurth holds a Ph.D. degree in political science from the University of North Carolina. breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o e h t he aut t

om r as ing-specif t ion ed f peset y publicat her t iles creat is h t L f

M of

and ot X om yles, r f st version print posed e h heading recom use t breaks, ease l been P

word has ed. hs, insert ally line lengt original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion. om r ibut f r t cannot r at not INDEX o f however, version ng,

i t paper book, at ive at rm o riginal horit ic f o

e A See also Evaluation of engineering h t he aut

t projects; Acid rain, 5 om r as Monitoring activities ing-specif

t Adaptive management, 51 Assimilative capacity, 3, 9 n.2 ion

ed f Agroecosystems Automation, in complex systems, 67 peset coevolutionary perspective, 20, 21-22, y 24-25

publicat B her t dispute resolution in, 170 iles creat is

h Benchmark data, 103, 104 t ecological health as goal of, 102 L f

M of Biodiversity

grassland grazing, 36 and ot X natural systems vs., 17 characteristics, 195 n.5 om yles, r Alternative dispute resolution, 169-170 in coevolution of human and natural f st version Asiatic clam, 22-23 systems, 21-22, 23 Assessment of ecosystem health, 15-18 ecosystem resilience and, 36-37, 39-40 print posed

e in applied ecology, 112 ecosystem services and, 16-17 h heading benchmark data, 103, 104 modeling, 55

recom conflict over methodology, 192-194 pollution response in ecosystems and, 83 use t constraints on human perception, 50-53 recommendations for maintaining, 27 breaks, ease

l replacement species, 17 been in ecological engineering, 119-120 P ecological integrity, 102-105 worldwide species diversity, 144 word has ed. for ecologically sensitive project design, Biosphere 2, 15 hs, 143-144 Biotechnology, 118 insert reversibility of environmental effects, Birds, 27

ally 58-59 Bonds, environmental assurance, 91-92, 93 line lengt values implicit in, 47-48 original work e h t

he original; ion of t at o ue t r have been accident y t a represent m are

l a errors

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om C Consumer behavior, 9 r ibut f r t cannot California. See San Francisco Bay/San Corps of Engineers, U.S. Army, 6, 111, r at not Joaquin Delta 193-194 o f Cattle grazing, 36 resource management philosophy, 187-189

however, Chaotic state, 20-21, 40-41

version Chemical pollution, 83, 103 ng,

t D paper book, Chesapeake Bay, 48 at ive

at Darns, 3

rm Chlorofluorocarbons, 69 o Coevolution, 19-24 Description, scientific, 47-48 riginal horit ic f

o Collaboration, ecology-engineering Design for environment, 4 e

h to convince others, 4 Design process t he aut t current practice, 2, 97-98, 111 ecological consideration in, 1-2, 111 om r as ing-specif ecological vs. engineering approach, 130 t design of development projects, 144-145

ion ecologically sensitive development ed f goals for, 67-68

peset need for, 1-2, 105-106, 185 projects, 143-144 y obstacles to, 6, 73 economic conceptualizations, 133, 136 publicat her t oil development in rain forest, 144-157 n.7 iles creat is h

t environmentally harmful outcomes, 2

L f opportunities for, 134-135

M of

political context, 132-134 environmentally sensitive engineering, and ot X receptivity of students, 130-131, 134 68 om yles, r Niobrara River engineering, 184

f science education and, 75-76 st version science policy and, 74-75 oil development project, 148-157 as scientific enterprise, 73 precautionary practice, 5-6 print posed e successful development projects, 143 problem definition, 2-4 h heading systems analysis, 131-132, 134-135 uncertainty in, 5, 6

recom Developing world, 67

use t See also Ecological engineering Command-and-control systems, 91 Differences between ecology and engi- breaks, ease l been Commons model, 50, 65 neering P Communications systems, 70 conceptualizations of sustainability, word has ed. Compartmental analysis, 84 129-130 hs, Complex systems, 4 expectations, 6 insert automation in, 67 perception of system resilience, 32-34

ally coevolutionary processes, 20-21 problem definition, 105 line lengt energy organization in, 83-85 original work

e E h human comprehension, 50, 52-53 t natural regulation, 7 Earth Summit (1992), 98-99 policymaking in, 73-74 Earthquakes, 8 he original; ion of t problem-solving in, 70 at o Ecological constraints on engineering quantification of interconnections in, definition of design success, 2-4 ue t r have been accident

y 84-85

t ethical consideration, 66, 67, 194-195 a revenge theory, 71-72 indications for, 1-2 represent m are

l substitutions/replacements in, 17, 71-72 modeling, 4 a transportation systems as, 70-71 principles for, 66-68 errors values implicit in study of, 48 in transportation engineering, 68-70 age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om Ecological economics, 19 conservation philosophy, 191-192 r ibut f r t

cannot valuation of ecosystem services, 14 constraints on human perception, 50-53 r at not Ecological engineering development projects in natural habitats, o

f applied, 116 141-144 biotechnology and, 118 diversity in, 83 however, conservation ethic, 117-118, 194-195 ecological resilience, 38-42 version ng,

i t definitions, 112-113, 114-115 engineering production philosophy, paper book, at ive

at environmental engineering and, 118 190-191 rm

o goals, 113 engineering resilience, 36-38 riginal horit ic f historical development, 112, 113-115 equilibrium state, 32, 33, 51 o e

h as integrative discipline, 123, 125-126 health of vs. integrity of, 100-102 t he aut

t principles of, 115 hierarchy theory, 51-52

om r as

ing-specif recent developments, 124-125 keystone processes, 60 t resource conservation in, 117 life span assessment, 81 ion ed f restoration ecology and, 119 nature of change in, 31-32 peset y role of, 123-124 near instability, 40-41 publicat

her t self-design concept in, 115-116 production-based vs. conservation-based iles creat is

h as system approach, 116-117 perspectives, 187-190 t L f

M of systems analysis in, 119-120 as public property, 50

and ot

X See also Collaboration, ecologists and restoration project objectives, 178-179 om

yles, engineers scalar problems in modeling, 46-50 r f st version Economics scientific understanding, 31-32, 47 conceptualizations of ecosystem ser- self-organization in, 115-116 print posed

e vices, 14-15 spatial attributes, 32 h

heading conceptualizations of equilibrium, 33 sustainability, 39, 81-83

recom engineering conceptualizations, 133, threats to, 99-100 use t 136 n.7 tropical rain forest, 144-145 breaks,

ease environmental accounting, 66-67, 68, See also Assessment of ecosystem health; l been P 92-94 Healthy systems word has

ed. environmental assurance bonding, Ecosystem services, 2 hs, 91-92, 93 in balance with technological services,

insert flexibility in resource management and, 7 24-27 identifying ecological costs, 92 defined, 13-14 ally

line lengt individual behavior, 86 ecosystem health and, 15-18 original work

e market diversity, 83 historical use, 20 h t

mixed-unit valuation, 85 human technology and, 20-24 modeling system interactions in, 84-85 human well-being and, 18-19 he original; ion of

t natural resource depreciation, 66-67 identification of, 14 at o sustainability concepts in, 177 perception of, 14 ue t r have been accident technological uncertainty and, 87-88 population growth and, 26 y t

a temporal orientation, 54 recommendations for maintaining, 27 represent m are

l valuation, 59-60 social consumption of, 13-14 a vs. ecosystem health, 23-24 technological alternatives, 15 errors Ecosystem functioning valuation of, 14-15 causes of failure, 191-192 Ecotechnology, 114 age breaks concept of sustainability, 81-85 Educational system, 75-76 P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om as setting for ecological-engineering Flow analysis, 84 r ibut f r t

cannot collaboration, 130-131, 134, 158-159 Forest management, 17, 37, 41-42 r at not Emergency responses, 68 oil development in rain forest, 144-145, o

f Endothermy, 7, 39-41 149-157 Energy Future generations, valuation issues, 54 however, in definition of ecology, 113-114 version ng,

i t electricity consumption, 15 G paper book, at ive

at optimistic/pessimistic expectations, 88 Game theory, 88-89 rm o sustainability of systems and, 82, 83-85 Global interaction, 56 riginal horit ic f Environmental engineering, 118

o ecological tariffs, 93-94 e

h Environmental Protection Agency, 173-175 environmental accounting, 92-93 t he aut

t Ethical issues, 66, 67, 72-73, 194-195 environmental awareness, 98-99 om r as ing-specif avoiding social traps, 90-91 Global warming, 5, 16 t Eutrophication ion Grasslands, 4, 36 ed f defined, 82 peset y system functioning, 82-83 H publicat her t Evaluation of engineering projects Harmful outcomes, 2 iles creat is

h ecological considerations in, 106 t

L f in coevolution of human and natural

M of ecological criteria, 2-4 systems, 21-24 and ot X ecologically sensitive development environmental assurance bonding om

yles, projects, 142 r

f against, 91-92, 93 st version engineering production philosophy, environmental modeling, 57-62 190-191 exotic invader species, 22-23 print posed e iterative testing process, 170-171, 176 n.5 expectations of, among scientists, 6 h heading long-term considerations, 9 human capacity to cause, 53

recom multiscalar decision making metamodel

use t human capacity to prevent, 6-7 for, 57-62 in human engineering, 129 breaks,

ease restoration project objectives, 178-179 l been implications of uncertainty for policy- P sustainability issues in, 177 making, 5-6 word has ed. Everglades. See Kissimmee River project Kissimmee River project, 164 hs, Evolutionary processes, 20-25 as long-term effects, 8-9 insert ecological integrity and, 101 oil exploration/development, 145 human behavior and, 86 ally recognition of, 97 line lengt nonpolluting ecosystems, 82 San Francisco Bay/San Joaquin Delta original work

e Exotic species, 18, 22-23 h management, 167-168 t Expectations Healthy systems ability to manage ecosystems, 6-7 biodiversity, 16-17 he original; ion of

t differences between ecologists and engi- at

o change processes, 31-32 neers, 6 characteristics of, 101-102, 195 n.5 ue t r have been accident regarding technological services, 13

y evaluation of, 102-105 t a Extinction of species, 23, 25 human well-being and, 18-19, 97 represent m are

l integrity of systems, 100-102 a F productivity in, 15-18 errors Fertility trends, 190 public understanding, 18-19, 25 Fisheries management, 37-38 resilience, 18 age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om restoring ecosystems, 26-27 overview, 164-166 r ibut f r t

cannot scalar factors in defining, 47 public controversy, 169 r at not technological optimism/pessimism, recent developments, 172 o

f 87-88 restoration objectives, 179-181 thresholds, 17 significance of, 163, 172, 175 however, Hierarchy theory, 51-52, 59-60 version ng,

i t Human Development Index, 67 L paper book, at ive

at Hydropower, 177 Labor-time-saving devices, 71 rm o Language of science, 47-48 riginal horit ic f I

o Life-cycle analysis e

h Illinois Waterway, 187, 192-194, 195 n.1 application, 4 t he aut t

Indigenous peoples, 150-151 ecosystems, 81 om r as ing-specif Individual decision making, 9 Life span t

ion commons model, 50, 65 behavior and, 86 ed f

peset determinants of, 19 quality of life and, 80-81 y evolutionary factors, 86 Local conditions publicat

her t game theory, 88-89 global considerations, 76, 93 iles creat is h

t hierarchy theory, 51-52 land planning, 68 L f

M of regional ecosystem management strate- policy scale, 55-56 and ot X social traps in, 86-87 gies, 7, 16-17 om yles,

r system interactions, 86 resource management, 17-18, 104 f st version Industrial processes, 68 Long-term effects, 8-9 Information feedback in natural systems, 20 of ecotechnology practice, 124 print posed

e Innovation of engineering in natural habitats, h heading in policymaking, 91-94 141-142

recom precautionary practice and, 5-6 social traps, 86-87 use t Input-output analysis, 84, 85 technology development and, 86, 106 breaks, ease l been Interdisciplinary initiatives uncertainty effects and, 87-89 P ecotechnology as integrative discipline, water resource management, 103, 175 word has ed. 123-124, 125-126 hs, for policymaking, 97-98 M insert International comparison, quality of life, 67 Materials balance approach, 84

ally International relations, 21 Migratory species, 27 line lengt Iterative testing process, 170-171, 176 n.5 Mississippi River, 6, 111, 187, 192-194, original work e

h 195 n.1 t J Models Jefferson, Thomas, 74-75 behavior of complex systems, 84 he original; ion of t at o commons concept, 50, 65 K decision making metamodel, 57-62 ue t r have been accident y t Keystone processes, 60 ecological constraints on design, 4 a Kissimmee River project, 2, 3, 111 ecological engineering, 116-117 represent m are

l ecosystem failure, 191-192

a litigation over, 171-172 management strategies, 169-170, 178, ecosystem stability, 33-34 errors 179, 182-184 age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om environmental problems as scalar prob- P r ibut f r t cannot lems, 46, 55 Pareto Optimality criterion, 61-62 r at not game theory, 88-89 Pesticides, 21, 40-41 o f global ecology, 93 Policy-making hierarchy theory, 52

however, alternative dispute resolution in, 169-170 multimetric, 104-105

version to avoid social traps, 90 ng,

i t multivariable problems, 71 paper book, command-and-control approach, 91 at ive

at Newtonian, 45, 46-47

rm conservation philosophy, 192 o transportation systems, 70-71 constant yield goals in, 32 riginal horit ic f uncertainty effects, 5-6, 87-88 o ecological health as goal of, 101-102 e

h values implicit in choice of, 46, 47 engineering production philosophy, 190, t he aut

t water management, 105 191 om r as

ing-specif Monitoring activities, 7

t environmental knowledge for, 25, 27 Kissimmee River flood control, 183-184 ion ed f environmental modeling for, 55 long-term, 175 peset implications of uncertainty, 5 y oil development project, 157-159 interaction of engineering and ecology publicat her t San Francisco Bay/San Joaquin Delta and, 68, 73-75 iles creat is

h water management, 174-175 t

L f interdisciplinary initiatives, 97-98

M of

Kissimmee River management, 163, and ot X N 169-172 om yles, r National Environmental Policy Act, 189,

f metamodel for, 57-62 st version 193, 195 n.2 micromanagement in, 73 Network analysis, 84-85 motivation for, 19-20 print posed e New technology, 5-6 optimistic vs. pessimistic approach, 89 h heading Niobrara River, 3, 178, 184 Pareto criterion, 61-62

recom Non-point-source pollution, 48 use t pluralistic approach, 46 Nonrenewable resources, 3 precautionary approach, 5-6, 93 breaks, ease l been Nonsuch Island, 23 problem formulation, 48 P production-based vs. conservation-based word has ed. O approaches, 187-190 hs, Oil development/exploration, 3 recommendations for sustainability, insert harmful effects, 145 91-94

ally offshore model, 152-154 San Francisco Bay/San Joaquin Delta line lengt pipeline options, 154-157 management, 173-175 original work e

h process, 146-147 Scalar considerations, 55-56 t rain forest project, 144-157 tax reform, 93 science and engineering needs, 157-159, water management, 103-104 he original; ion of t

at waterway navigation system, 192-194 o 160-161 strategies to minimize impacts, 148-154 Pollution ue t r have been accident

y boundaries, 3

t sustainability issues, 159-160 a Oil exploration chemical, 83, 103 represent m are

l ecologically sensitive projects, 142 definition, 81-82 a Opportunity costs, 6 ecosystem response, 83 errors Organized labor, 99 energy/entropy characteristics, 82, 83-85 eutrophication as, 82-83 age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om evolutionary perspective, 82 Q r ibut f r t cannot polluter assurance bonding against, Quagga mussel, 22-23 r at not 91-92, 93 Quality of life o f scalar issues in study of, 48 in built environment, 67 as social trap, 87

however, goals, 72-73 sustainable use, 81-82, 83

version life span considerations, 80-81 ng,

i t transportation-related, 69 paper book, obligations of engineering profession, at ive

at water, 103

rm 67-68 o Population growth population growth and, 74 riginal horit ic f ecological threat of, 24-25, 26 o quality of environment and, 65-66, 100 e

h optimistic/pessimistic expectations, 88 t he aut

t public understanding of, 19 R om r as

ing-specif quality of life and, 74 t Recreational activities, 17 social goals, 27 ion ed f Renewable resources, 3 Stabilization, 26 peset

y Resilience of ecosystems, 18 trends, 25-26 conceptualizations of, 32-34 publicat

her t Precautionary principle, 5-6, 93

iles creat ecological management for, 38-42 is

h Primitive peoples, 24 t L f engineering conceptualization, 33-34 M of Probability, uncertainty and, 5-6

and ot engineering management for, 36-38

X Problem definition, 2-4 system variability and, 39-40 om

yles, in concept of sustainability, 79 r

f Resource management st version engineering vs. environmental approach, adaptive, 51 105 boundaries of use, 3 print posed

e sociohistorical trends, 65

h challenges, 6-8 heading values implicit in scalar choices, 48 ecological engineering principles,

recom Production-based philosophy

use t 117-118 in engineering, 190 ecological health as goal of, 101-102 breaks,

ease limitations of, 190-191 l been economic reliance upon, flexibility and, 7 P vs. conservation-based approaches,

word ecosystem resilience and, 38-42, 51 has

ed. 187-190

hs, engineering resilience and, 36-38 Productivity, 7 human development and, 24-25, 86, 101 insert conceptualizations of natural systems, innovative policy-making, 91-94 135 n.2 ally iterative testing process, 170-171, 176 n.5 line lengt ecosystem health and, 15-18

original work local vs. global, 17-18

e scale discontinuity in ecosystems, 32 h

t monitoring effects of, 7 Public interest, commons model, 50, 65 natural processes vs., 7 Public perception/understanding, 68

he original; population growth and, 26 ion of

t to avoid social traps, 90 at o production-based vs. conservation-based current awareness of environmental approaches, 187-192 ue t r have been accident issues, 98-99 y t species replacement, 17 a of ecosystem health, 18-19, 25, 106 Restoration ecology, 26-27, 52 represent m are

l knowledge needs, 27

a ecological engineering and, 112, 113, quantification of ecosystem services, 16 116, 119 errors questions of scale, 45-46 Kissimmee River objectives, 179-181

age breaks P is new digit h pographic y iles. T t

f e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om objectives for streams and rivers, 178, evolutionary processes, 86 r ibut f r t

cannot 181-182 expectations regarding technological r at not Revenge theory, 8, 71-72 services, 13 o

f Rio Summit. See Earth Summit (1992) identifying ecological costs, 92 Risk(s) individual interests vs. social interests, however, de minimis concept, 195 n.4 8-9 version ng,

i t definition, 5 infrastructure as expression, 72 paper book, at ive

at model for environmental decision mak- perception of ecological services, 14 rm

o ing, 57-62 policy scales, 55-56 riginal horit ic f problems of scale in, 45 o

e S

h rain forest development considerations, t he aut

t 145-146, 150-151 Safety factors design, 6 om r as ing-specif San Francisco Bay/San Joaquin Delta science in, 76 t See also Social values ion management strategies, 173-175 ed f Spatial/temporal scales peset overview, 166-169 y significance of water management expe- attributes of ecosystem functioning, 32 publicat

her t rience, 163, 175 in concept of sustainability, 79-81 iles creat is

h current conceptualizations, 45

t Scientific method L f

M of in engineering design, 133

applied vs. pure research, 74-75 and ot X contributions of, 73 environmental problems as scalar prob- om

yles, lems, 46-50 r in ecological engineering, 119-120, f st version 125-126 hierarchy theory, 52 education and training for, 75-76 human perception of, 50-53 print posed

e evaluative content, 47-48 human values and, 53-57 h heading Social engineering, 67 modeling environmental effects, 58-59

recom Social traps, 23-24, 86-87 modernist conceptualizations, 45, 46-47 use t educational prescriptions, 90 perspectivist view, 45-46 breaks,

ease phenomenology, 61 l been policy prescriptions, 90 P sociocultural prescriptions, 90-91 Stabilization word has ed. technological uncertainty and, 87-89 ecological health vs. ecological hs, Social values, 8-9 integrity, 100-102

insert in adaptive management techniques, ecosystem equilibrium, 32, 51 ecosystem resilience, 33-34, 38 ally 51-52

line lengt commons model, 50 population growth, 26 original work

e as restoration project objective, 178-179

h determinants of, 50-51 t ecosystem services, 14 Standard of living, 25 hierarchical thinking, 52 environmental accounting, 66-67 he original; ion of t implicit in environmental models, 46, 47 Human Development Index, 67 at o interdisciplinary examination of, 47 Sustainability, 1 ue t r have been accident scalar problems, 45, 46, 48 conservation philosophy, 191-192 y t a temporospatial scaling in, 53-57, 61 definitions, 9 n.1, 79-81, 177-178 represent m are

l See also Valuation in development projects, 177, 178 a Sociocultural context, 1 ecological concerns, 129-130 errors avoiding social traps, 90-91 ecological engineering goals, 117 benefits of ecologically sensitive engi- economic concept, 177 age breaks neering, 2-3 P is new digit h

pographic consumption of ecological services, y iles. T t

f 13-14, 24 e ile: ng i f t F D P peset and som is y h t

ined, a bout A ret original t

ion.

om ecosystem services and, 14 determinants of, 51 r ibut f r t

cannot engineering conceptualizations, 129 in economics, 59-60 r at not environmental accounting, 92-94 ecosystem services, 14-15, 16 o

f legal threshold, 195 n.4 environmental, in engineering account- in natural systems, 39, 41-42, 81-85 ing, 66, 68 however, prediction of, 79-80 mixed-unit, 85 version ng,

i t technological development issues, scalar problems, 46 paper book, at ive

at 159-160 spatiotemporal consideration, 52 rm

o temporospatial concepts embedded in, See also Social values riginal horit ic f 79-81 o

e W

h temporospatial thinking, 54-55 t he aut

t Systems perspective, 4 Water management, 3, 7 om r as ing-specif coevolution, 19-24 benchmark data, 103, 104 t component interaction, 83, 84 ion California drinking water, 8 ed f concept of resilience, 32-33 peset Chesapeake Bay cleanup, 48 y concept of sustainability, 9 n.1, 79-81 ecological goals, 177 publicat

her t in ecological engineering, 116-117, evaluation of river ecosystems, 4 iles creat is

h 119-120

t flood control, 182-184 L f

M of ecosystem health in, 15-18

hydropower initiatives, 177 and ot X eutrophication processes, 82-83 measurement and evaluation practices, om

yles, individual behavior in, 86 r 102-103 f st version natural systems, 7 multimetric modeling, 104-105 political context, 132-134 navigation systems, 187, 192-194 print posed

e revenge theory, 8-9, 71-72 policy, 103-104 h heading role of diversity, 83 production-based vs. conservation-based

recom self-organizing behaviors, 115-116 approaches, 187-190 use t similarities in ecology and engineering, restoration project objectives, 178-179 breaks,

ease 131-132, 134-135 l been threats to, 103 P in water quality monitoring, 175 See also Kissimmee River project; word has ed. San Francisco Bay/San Joaquin Delta hs, T Wetlands development, 142, 158

insert Tariffs, 93-94 Whooping Cranes, 184

ally Tax reform, 93

line lengt Taxes, 172 Z original work e

h Technological optimism/pessimism, 87-89 Zebra mussel, 22-23 t Technological services in balance with ecosystem services, 24-27 he original; ion of t current consumption, 13 at o human development and, 24-25 ue t r have been accident Threshold concept, 17, 195 n.4 y t a Transportation systems represent m are

l complexity of, 70-71 a environmental issues, 69-70 errors pollutants, 69

age breaks U P is new digit h

pographic Uncertainty, 5-6 y iles. T t

e in origin of social traps, 87-89 ile: ng i f

t Unknown unknowns, 5, 6 F

D Unknowns, 5 P peset Urban populations, 69, 70 and som is y h t

ined, V a bout A ret original t Valuation