WORLD RESOURCES INSTITUTE KEEPING OPTIONS ALIVE: The Scientific Basis for Conserving Biodiversity WALTER V. REID KENTON R. MILLER KEEPING OPTIONS ALIVE: The Scientific Basis for Conserving Biodiversity Walter V. Reid Kenton R. Miller WORLD RESOURCES INSTITUTE A Center for Policy Research October 1989 Library of Congress Cataloging-in-Publication Data Reid, Walter V. C, 1956- Keeping options alive. (World Resources Institute Report) Includes bibliographical references. 1. Biological diversity conservation. I. Miller, Kenton. II. Title. III. Series. QH75.R44 1989 333.9516 89-22697 ISBN 0-915825-41-4 Kathleen Courrier Publications Director Brooks Clapp Marketing Manager Hyacinth Billings Production Manager Organization of American States; Mike McGahuey, World Bank photo/James Pickerell Cover Photos Each World Resources Institute Report represents a timely, scientific treatment of a subject of public concern. WRI takes responsibility for choosing the study topics and guaranteeing its authors and researchers freedom of inquiry. It also solicits and responds to the guidance of advisory panels and expert reviewers. Unless otherwise stated, however, all the interpretation and findings set forth in WRI publications are those of the authors. Copyright © 1989 World Resources Institute. All rights reserved. Reprinted 1993 Contents I. Introduction 1 Global Warming 52 Cumulative Effects 55 II. Why is Biological Diversity Important? .. .3 V. What's Happening to Agricultural The Role of Biodiversity in Ecosystems... 4 Genetic Diversity? 57 Ecological Processes 4 Ecological Dynamics 6 Uses of Genetic Diversity 57 In Situ Conservation 59 III. Where is the World's Biodiversity Ex Situ Conservation 61 Located? 9 VI. Biodiversity Conservation: What are the General Patterns of Species Right Tools for the Job? 67 Distribution 9 Species Richness 10 Land-use Zoning and Protected Areas .. 67 Commonness or Rarity 17 Status of Protected Areas 69 Species of Current Economic Value 22 Potential Conservation Importance .... 70 Food 23 Reserve Size, Network Design, and Medicines 27 Transition Zones 78 Industrial Uses 29 Ecological Restoration and Rehabilitation 80 IV. Extinction: How Serious is the Ex Situ Conservation 81 Threat? 31 Zoos and Aquaria 82 Botanic Gardens 84 Trends in Species Extinctions 31 The Geography of Extinction 39 VII. Summary and Recommendations 87 Freshwater Ecosystems 40 Islands 41 Appendices 99 Mediterranean Climate Zones 43 Temperate Regions 44 1. Cascade Effects 99 Tropical Forests 45 2. Calculating Extinctions Due to Causes of Extinction 45 Deforestation 102 Habitat Loss and Fragmentation 45 3. Protected Area Objectives 105 Over-exploitation 50 4. Glossary 106 Species Introductions 51 Pollution 52 References Ill Foreword s the 21st Century approaches, the Still another reason for optimism is the rapid world is being impoverished as its strides now occurring in conservation biology A most fundamental capital stock—its and landscape ecology. Scientists' understand- species, habitats, and ecosystems—erodes. Not ing of how to maintain viable breeding popula- since the Cretaceous Era ended some 65 mil- tions of species and provide sufficient habitat lion years ago have losses been so rapid and to support them has grown dramatically since great. If the trend continues, one quarter of the the late 1970s, as has the availability of effec- world's species may be gone by 2050. Desertifi- tive conservation techniques. Worldwide, more cation, fisheries collapse, tropical deforestation- people trained in forestry, ecology, conserva- such losses already attest amply to how much tion biology, and other key fields are needed, biological impoverishment costs human beings. but their ranks are beginning to grow. If we continue to borrow from the future, liter- ally eating our seed corn, those costs will rise. For all these reasons, the chances of revers- ing the current trends in many ways look bet- An alarm has been sounded. In response, ter now than they did only a few short years the number of international organizations, ago. But agreement is universal that current national governments, and non-governmental efforts are insufficient. What is needed is a organizations concerned about biodiversity and coordinated attack on the problem at its roots, the breadth of their activities has increased one that both makes use of the best modern dramatically during the last decade. Under science and reflects concern for the human their wings, protected areas, zoos, botanical well-being of those most affected. Only when a gardens, aquaria, seed banks, and other sanc- "critical mass" of participants are cooperating tuaries and research stations have been set up in a "critical mass" of initiatives within the to rescue and propagate endangered species. framework of a common strategy will biological Some of the participants in this new movement diversity be saved. This cooperation must are institutions working to demonstrate the involve an active participation among govern- compatibility of ecosystem protection and eco- mental and non-governmental organizations in nomic development; others are integrating both developing and industrial countries. development planning and crafting an interna- tional convention for preserving biodiversity. In a way, Keeping Options Alive is a "how to" Some development assistance agencies are con- publication. Its timely premise is that the bio- sidering how their grants and loans affect bio- logical sciences can help policy-makers identify diversity, and various groups are exploring the threats to biodiversity, evaluate conserva- new ways to finance the conservation of bio- tion tools, and come up with successful logical diversity. management strategies to the crisis of biotic v impoverishment before it is full-blown. To of the financing, technology, and knowledge these ends, Reid and Miller provide an over- needed to implement them. But creating a view of where the world's species and genetic decision-making framework based on the most resources are located and why they are valu- current and comprehensive scientific under- able, a new analysis of species extinctions in standing of the world's biological wealth is tropical forests that supports previous estimates essential when so much of it has yet to be and reinforces the magnitude of the problem inventoried, much less evaluated, and when that we face, and a survey of the most recent some of the potentially most important species findings of conservation biology. The authors and ecosystems have few politically empow- also suggest how these findings can best be ered constituents. Only by marrying scientific put to work for both in situ and ex situ conser- fact to political and economic reality—as Keep- vation, and they add to evidence that the bio- ing Options Alive strives to help policymakers diversity crisis is not restricted to tropical do—can we hope to maintain the biological forests, but threatens biological resources in wealth on which long-term economic develop- temperate zones and marine ecosystems as ment depends. well. Finally, this report underscores the important interdependence between biological WRI would like to express its great apprecia- diversity and human cultural diversity and the tion to The Rockefeller Foundation, Inc., John policy implications of this critical bond. D. and Catherine T. MacArthur Foundation, Town Creek Foundation, Inc., The Pew Ultimately, of course, the solution to the bio- Charitable Trusts, W. Alton Jones Foundation, diversity crisis will be political. It will require Inc., The Moriah Fund, Waste Management, both improving planning and management and Inc., and HighGain, Inc., which have provided redressing the social inequities that force peo- financial support for WRI's efforts in this area. ple and nations to use resources unsustainably. Indeed, many of the long-term actions that James Gustave Speth Reid and Miller call for in Keeping Options Alive President will not occur in the developing world unless World Resources Institute the industrial countries provide their fair share VI Acknowledgments e are grateful to Mohamed El- Ashry, Nate Flesness, Tom Fox, W Vernon Heywood, Dan Janzen, Nels Johnson, Jeffrey McNeely, Gordon Orians, Peter Raven, Ulysses Seal, Dan Simberloff, Michael Soule, Mark Trexler, and Geerat Vermeij for their valuable comments on all or parts of the draft report. Our thanks to Kathleen Courrier for skillfully editing the report and to Hyacinth Billings, Allyn Massey, and Moira Connelly for their help preparing the text and figures. Special thanks to Dee Boersma, Kai Lee, Jeffrey McNeely, Gordon Orians, and Robert Paine for many invaluable discussions on ecology, conservation, and development. W.V.R. K.R.M. VII I. Introduction ur planet is a biologically impoverished "services"—such as the regulation of water image of the world that supported discharge and the absorption and breakdown O humanity in past generations. We can of pollutants—are being degraded as compo- no longer thrill to the sight of waves of migrat- nent species vanish from these ecosystems or ing passenger pigeons—extinct since 1914—and as natural habitats are converted to other land no tourist industry will be built around the uses. The erosion of the genetic diversity of Caribbean monk seal, the last of which died in agricultural, forestry, and livestock species 1960. Losses of mangrove habitat in many diminishes the potential for breeding programs Southeast Asian nations have diminished the to maintain and enhance productivity. productivity