RestorationRestoration EcologyEcology Courtesy of Michael R. Wagner A New Forest Management Paradigm, or Another Merit Badge for Foresters?

hat ecological restoration is a growing field is illustrated Tby the startup of a professional association (the Society for Ecological Restoration, created in 1987), the development of two new journals (Restoration Ecology and Ecological Restoration, the latter having been Restoration and Management Notes), and the publication of 50 or more papers each year. In the

22 October 2000 Forest Restoration Multiple-Use Management

Southwest alone, several large forest tails negotiating the best possible out- restoration projects are under way. come for a specific site based on eco- Focusing on the Southwest but raising ques- The notion of “restoring” ecosys- logical knowledge and the diverse per- tions that are more broadly applicable,we tems seems laudable enough. For some, spectives of interested stakeholders.” compare ecological restoration with conven- however, ecological restoration assumes Certainly, restoration generally as- tional management regimes—multiple-use a moral imperative for a “bold new ori- sumes a holistic perspective and a need management,ecosystem management,and entation toward nature” (Higgs 1991). for active intervention, but that hardly managing for specific resource objectives. We evaluate ecological restoration in distinguishes it from ecosystem man- That restoration assumes a holistic perspec- the larger context of other land man- agement or other approaches for tive and active intervention does not distin- agement philosophies like multiple-use achieving ecosystem health (sustain- guish it from other approaches to achieving management, ecosystem management, ability, integrity, etc.). Is ecological and managing for specific resource ob- restoration the only way to achieve eco- ecosystem health.We find that foresters and jectives (e.g., wildlife, commodity pro- system health? If a management activ- restorationists both use ecology,but restora- duction). We ask, is ecological restora- ity improves forest health, is it then tionists use a reference condition as a substi- tion sufficiently conceptually devel- ecological restoration? tute for specific objectives.We believe that oped, experimentally tested, and neces- What distinguishes restoration from restorationists who advocate substituting a sary to warrant its adoption as a new other land management activities is reference condition for meeting a priori ob- forest management paradigm? that recovering the ecological integrity jectives must demonstrate the advantage of of a site requires using the techniques this approach.We identify the conceptual lim- Ecological Restoration, Defined of reestablishing the composition, itations to ecological restoration and ques- The techniques, objectives, and de- structure, and disturbance regime of a finitions of ecological restoration have historical or indigenous reference eco- tion the uses of restoration. evolved over the past decade as practi- system (Cairns 1993; Meffe and Car- tioners and scientists sought to define a roll 1994; Bradshaw 1996). new, applied discipline. Between 1991 By Michael R.Wagner, and 1997 the Society of Ecological Choice of Reference William M. Block, Brian W.Geils, Restoration modified its definition of A reference or standard is essential and Karl F. Wenger ecological restoration five times for planning and monitoring any pro- (Palmer et al. 1997). Restoration was ject that promises to produce certain first used to describe landscaping and results within given specifications. De- replanting to reclaim stripmines and sired conditions and performance stan- toxic dumps. Later, restoration de- dards may be determined by a collabo- scribed agricultural lands that were re- rative decision process that assesses the vegetated to resemble native prairies, likely outcome of alternative manage- and new wetlands that were created to ment policies. A restorationist’s ap- replace those lost to other uses. More proach is to define desired conditions recently, and especially in southwestern and standards as those exemplified by a forests, the term forest restoration has specific historical or indigenous ecosys- been used to describe activities in- tem. For the Southwest, a preferred ref- tended to recreate the forest structure erence is the ponderosa pine forest that and fire regime that prevailed just prior existed just prior to European settle- to Euro-American settlement (Coving- ment, produced under a disturbance ton and Moore 1994; Covington et al. regime of frequent ground fires result- 1997; Stone et al. 1999). ing in open stands with groups of large The purpose of restoration has been ponderosa pine trees and a sparse variously described as repairing dam- woody understory but dense grassy age, renewing ecosystem health, recov- cover (Covington et al. 1997). Opposite: A stand of ponderosa pine ering ecological integrity, and regener- Although some dendrochronology as captured in this historical photo- ating harmony between humans and data support the contention that fire graph (circa 1890s) from the Coconino nature (SER 1994; Higgs 1997; Palmer occurred at a regular but variable fre- National Forest, Arizona. Clumps of et al. 1997). Health and integrity refer quency prior to Euro-American settle- large-diameter ponderosa pine and to desired biological diversity and sus- ment, there is also some relatively new open savannah between clumps are the tained ecosystem functioning. In terms information based on extensive re- common reference condition used in familiar to foresters, a recent Society of search in other ponderosa pine stands the Southwest. Note in the background Ecological Restoration workshop defi- suggesting that the severity, frequency, somewhat more dense pockets of nition read, “ecological restoration en- and spatial occurrence of fire was even young trees.

Journal of Forestry 23 may never be repeated, so why should we assume that a past forest structure is better suited to the much different cli- mate that exists today? Add uncertain global climate change and Pacific decadal oscillations, and recreating for- est structure to reflect a unique histori- cal climate seems of dubious value. From a forest management perspec- tive, a climatic pattern that has per- sisted for 200 years is more than ample time to produce one or two rotations of multiple products. It seems most sensible to manage existing forests in the existing climate to meet current ob- jectives rather than managing to recre-

Michael R. Wagner ate the past. Aronson et al. (1995) in- An abundance of the exotic mullein (Verbascum thapsus), which was largely absent sist that a reference ecosystem, even if in the untreated control,is apparent in the understory vegetation five years after a arbitrary and imperfect, is necessary for full restoration treatment in ponderosa pine at Fort Valley Experimental Forest, the design and evaluation of restora- Arizona.Details of the treatments are in Stone et al.(1999). tion projects. The question, however, is whether any single ecosystem condi- more variable than previously thought nessee had “vast quantities of maize.” In tion is a sufficient reference if it was the (Shinneman and Baker 1997; Brown et the Coosa Valley of present-day Al- product of a unique combination of al. 1999). Brown et al. also clearly abama they found “large and numerous climate and human interaction that demonstrate the existence of stand-re- settlements and the fields were continu- may never be repeated. placing fires, which had rarely been ous” (DeVivo 1992). considered a component of the south- The European immigrants of the Obstacles to Restoration western reference condition. early 17th century found perhaps only The evolving science and theory of small, scattered villages, still rather ex- ecosystems. Ecosystems are always re- The Presettlement Condition tensive open fields, but also “dense sec- sponding to previous disturbances: tree Human influence on forest condi- ond-growth forests characterized by fall, firestorm, volcanic eruption, ice tions prior to European settlement is fifty to 100 year old trees, unhindered ages, and meteor strikes. Ecosystem de- underappreciated. The latest estimate of by human impact.” This offered the il- velopment after disturbance is greatly the native population of North America lusion of “virgin forest” (DeVivo influenced by chance; what remains at the time of discovery is 50 million. 1991). Similarly, in the Southwest and what is nearby influence ecosystem According to DeVivo (1991), the pre- there were periods of occupation and trajectory. Ecosystems endure with contact New World population peaked abandonment by native peoples. Thus, change. Species evolve and are re- between 90.04 million and 112.55 mil- the activities of native peoples were the placed, structures are built and decay, lion indigenous people, equally split be- major agents determining the vegeta- process rates vary but life goes on. The tween North and South America. But tive conditions over much of the significance of these characteristics is Europeans introduced diseases for United States until the time of the Rev- that every ecosystem is unique to the which the natives had no resistance. As olutionary War. Should the reference place and time in which it exists. the inhabitants tried to flee the diseases, condition include or exclude the Ecological restoration relies on they apparently spread them through- human impact of indigenous people? many ecological concepts, some of out eastern North America. DeVivo which are not clearly understood; oth- concludes, “No doubt, the aboriginal Transient Climate ers are still being defined and tested. inhabitants of mainland North America Dendrochronology studies in the One of the basic concepts of succession suffered dramatic population decline Southwest suggest that from roughly was once viewed as a single, determin- before face-to-face contact with Euro- 1800 to the present, the climate was istic pathway to a climatic climax type. peans” from the diseases introduced by substantially wetter than from 1400 to This basic concept has been replaced by the Europeans. The population decline 1800 (Grissino-Mayer et al. 1997) (fig. a nonlinear model of exploitation-con- apparently had not yet run its course 1). The common reference period in servation-release-reorganization (Holl- during the 1539–42 DeSoto expedition the Southwest is the pre–European set- ing 1995). For example, restorationists through what is now the eastern United tlement period of roughly 1860 to the often cite a need for diversity to en- States. In the Blue Ridge Mountains 1880s, or 60 to 80 years after a 400- sure ecosystem stability. The ecologi- they marched for “one day through cul- year dry period. The climate that cre- cal debate on that issue has progressed tivated fields.” Towns in eastern Ten- ated this popular reference condition from discussions on stability to re-

24 October 2000 silience, to a recent suggestion that overconnectedness leads to brittleness 3 (Holling 1995). Likewise, it is equivo- cal whether diversity creates stability 2 or structure ensures function in ecosystems. New ecosystem components. Another 1 major obstacle in restoration is dealing with the components of the ecosystem 0 that are present now that didn’t exist previously or organisms that exist in –1 greater numbers than before. Specifi- cally, we are referring to exotic organ- isms. The open vegetation structure –2 precipitation precipitation and reintroduction of fire as a distur- Below-average Above-average bance agent that characterize forest –3 restoration in the Southwest are also 200 BC 1 200 400 600 800 1000 1200 1400 1600 1800 2000 conditions that are highly suitable for Year invasive species. With the exception of Allen (1995) and Montalvo et al. Figure 1. A 2,129-year reconstruction of precipitation based on 10-year averages (1997), few authors have discussed the for northwestern New Mexico.Unprecedented above-average precipitation charac- relationship between ecological restora- terizes the most recent 200-year period,which was preceded by significant tion and increased invasion by exotic droughts.Which climatic period should be used as the reference condition? species. Some authors have suggested Source: Grissno-Mayer et al.1997 that exotic invasions can be beneficial (Hobbs and Mooney 1993). Recent trees that provide a diversity of habitats rently under forest management—we data on understory vegetation response (multiple use); harvest and regenera- want to use the example of ecological (Griffis et al., in press) suggest that ex- tion activities that protect soil and restoration and wildlife. otic species respond dramatically to the water (sustained yield); and fire, insect, Numerous goals underlie traditional reintroduction of fire as part of surro- and disease within acceptable limits management of wildlife, including gate restoration treatments (fig. 2, from a long-term perspective (forest maintaining viable populations of all p. 26). This response is also visually health). Silvics, silviculture, mensura- native and desired nonnative vertebrates dramatic in full restoration treatments. tion, and forest protection indicate that (prescribed by the National Forest Man- Consequently, in forests where exotic these are realistic objectives, achievable agement Act of 1976), recovering species become established, ecological using tools like timber harvest. threatened and endangered species restoration treatments may create a for- Foresters and restorationists use the (mandated by the Endangered Species est health problem that is as undesir- same ecology, but restoration ecologists Act of 1973), and providing consump- able as the pretreatment condition. use a reference condition as a substitute tive (hunting, fishing, trapping) and Societal needs. What often distin- for specific objectives. Creating a refer- nonconsumptive (birdwatching, pho- guishes foresters from ecologists is that ence ecosystem condition has its greatest tography) recreational opportunities. To foresters are asked to manage forests to utility as a research tool to better under- achieve these goals, management is achieve specific societal objectives stand how ecosystems function (Ehren- often directed at maintaining or en- within ecological constraints. Forestry feld and Toth 1997; Michener 1997). hancing conditions for focal species. In as an applied science has developed We certainly recognize understanding contrast, ecological restoration is guided alongside ecology. These sciences ma- ecosystems as a laudable goal of ecologi- by broader goals that emphasize ecosys- tured together and benefited from in- cal restoration. Fixing badly degraded tem composition, structure, and func- teraction. A science can be defined by ecosystems—landscapes that have been tion rather than specific ecosystem ele- the questions it asks. Forestry asks how deforested or contaminated with envi- ments. Implicit in restoration is the as- trees grow, respond to competition and ronmental toxins—also is an important sumption that successful restoration will release, and reproduce. Foresters are ecological restoration objective (Dobson provide favorable conditions for native also interested in maintaining soil, et al. 1997). Again we concur this is a species of wildlife. Thus, effects of water, and species other than trees. laudable use of restoration. restoration on wildlife are more appro- Tending a stand of trees is seen as a Compatibility with achieving other priately considered an outcome rather long-term commitment, but econom- values. To answer the question we pose than a specific goal of management. ics dictates a minimum of interven- in our title—whether restoration Given that traditional approaches to tion. A forester could be satisfied with should be viewed as an alternative land wildlife management are mandated by an age-diverse landscape (regulated for- management paradigm for the bulk of law or deeply imbedded in many soci- est) of stocked stands of well-growing forest lands in the United States cur- eties (Leopold 1933, 1949), it is un-

Journal of Forestry 25 that we have sufficient knowledge of 1.2 Unmanaged how ecosystems function to get there. Thinned 1.0 3. Previous forest conditions, at Thinned and burned least when applied across a landscape 0.8 Wildfire scale, probably do not better meet so-

0.6 cial needs and desires than other alter- natives currently available. 0.4 There are in addition several other issues that relate to the feasibility of 0.2 ecological restoration—economics, in- Ratio of exotic to native species 0 stitutional constraints, sustainability, Abundance Species richness and difficulty in achieving societal con- sensus—that we do not have space to Figure 2. Ratio of exotic to native understory species in ponderosa pine forests discuss. Restoration prescriptions in following four experimental stand treatments (Griffis et al.,in press). Surrogate the Southwest that lead to lower stand restoration treatments of thinning and burning significantly increased the propor- densities and the use of prescribed fire tion of exotic species,as did stand-replacing wildfire. are generally desirable. Conventional silvicultural prescriptions can, however, likely that ecological restoration will game management may be incompati- provide similar benefits while also supplant those approaches. The ques- ble with those of ecological restoration. achieving other societal values like im- tion then arises, Is ecological restora- The assumption that restoring vege- proved game habitat, protection of spe- tion compatible with established ap- tation structure and composition will cific endangered wildlife, and the pro- proaches to wildlife management, or lead to a “restored” wildlife community duction of marketable wood products. even desirable? Our conclusion is that is a field of dreams. To our knowledge, One’s orientation to the human role there is no assurance that ecological there is certainly no conclusive evidence in ecosystem management has much to restoration can sustain populations of to validate this assertion. Wildlife com- do with how one answers the question, all target species, nor is there assurance munities are dynamic and change as the Should ecosystems be restored to a previ- that managing for target species can re- result of natural phenomena and human ous condition? A forester views a recently sult in a restored ecosystem. influences. When the system is per- cut, regenerating stand under even-age Management of some target species, turbed, biotic and abiotic relationships management as a renewable resource to particularly threatened or endangered of the system’s components change. meet human needs. The previous condi- species, may entail a laissez-faire ap- Changes to the wildlife community may tion of the stand was part of a sustainable proach. This is often the case with take the form of population changes, ex- forest (the ecosystem) producing ecolog- species that rely on dense, mature for- tirpation or extinction of species, inva- ical services and extractable products. If ests, such as the threatened Mexican sion by exotic species, and changing re- regeneration is only a phase of a contin- spotted owl (Strix occidentalis lucida), or lationships (such as food webs) among uous process, is “restoration” even applic- species that use exotic plants like salt the remaining species. When a system is able? That past can never be reconsti- cedar (Tamarix chinensis) as an impor- “restored,” extinct species will not re- tuted, but perhaps an acceptable facsim- tant habitat element, such as the en- turn, exotic species often remain, popu- ile can and should be made. Other peo- dangered southwestern willow fly- lation levels may not return to “refer- ple want an area where natural processes catcher (Empidonax traillii extimus). A ence” levels, and community structure of growth, reproduction, and evolution restoration prescription calling for an and organization will likely be unique to occur without human presence. The fun- open forest structure would probably that place and time. Thus, will ecologi- damental difference in these perspectives not be permitted in areas occupied by cal restoration result in a restored is the relative degree of human involve- spotted owls, nor would salt cedar re- wildlife community? Undoubtedly, it ment in ecosystems. moval be possible in flycatcher nesting will not in most situations. In recent years, three concepts have areas. Such constraints would essen- emerged on the forest management tially preclude restoration as a viable Summary scene: forest health, ecosystem man- management option. Management Our article summarizes three broad agement, and now ecological restora- practices for many game species—wild issues that should be considered before tion. All of these concepts have initially turkey (Meleagris gallopavo), elk (Cervus foresters adopt an ecological restora- generated considerable debate, but we elaphus), and deer (Odocoileus)—often tion management paradigm: believe all are basically fully consistent require maintaining dense vegetation 1. Changing climate and land uses by with modern forest management activ- structure to provide nesting, bedding, humans make the selection of an appro- ities. Some authors define ecological hiding, and escape cover. Providing priate reference condition problematic. restoration in terms nearly synony- dense cover may be counter to restora- 2. Even if as a society we could agree mous with what many in the Society of tion prescriptions that strive for an that some previous condition was more American Foresters call “good forest open park-like forest. Here, goals of desirable, there is considerable doubt stewardship.” We welcome these new

26 October 2000 ideas and techniques, but restora- EHRENFELD, J.G., and L.A. TOTH. 1997. Restoration ecology and the ecosystem perspective. Restoration tionists who advocate substituting a Ecology 5:307–17. reference condition for meeting soci- GRIFFIS, K.L., J.A. CRAWFORD, M.R. WAGNER, and etal objectives must demonstrate the W.H. MOIR. In press. Understory response to man- advantage of this approach over con- agement treatments in northern Arizona pondersoa ventional silvicultural prescription. pine forests. Forest Ecology and Management. GRISSINO-MAYER, H.D. 1997. The rare, old-aged The question is not whether ecological conifers of El Malpais—their role in understanding restoration is good for ecosystems; but climatic change in the American Southwest. New rather, is it marginally better than the Mexico Bureau of Mines and Mineral Resources Bulletin other options available to improve eco- 156:155–61. HIGGS, E.S. 1991. A quantity of engaging work to be system health? Professional foresters done. Restoration and Management Notes 9:97–104. should carefully consider how they can ———. 1997. What is good ecological restoration? use ecological restoration on badly de- Conservation Biology 11:338–48. graded lands or as part of long-term re- HOBBS, R.J., and H.A. MOONEY. 1993. Restoration ecol- ogy and invasions. In Nature conservation 3: Recon- search where it is most appropriate, struction of fragmented ecosystems, global and regional and sew on another merit badge for a perspectives, eds. D.A. Saunders, R.J. Hobbs, and P.R. 100-year history of service as “ecologi- Ehrlich, 127–33. Chipping Norton, New South cal restorationists.” Wales, Australia: Surrey Beatty & Sons. HOLLING, C.S. 1995. What barriers? What bridges? In Barriers and bridges to renewal of ecosystems and insti- Literature Cited tutions, eds. L.H. Gunderson, C.S. Holling, and S.S. ALLEN, E.B. 1995. Restoration ecology: Limits and pos- Light, 3–34. New York: Columbia University Press. sibilities in arid and semiarid lands. In Proceedings: LEOPOLD, A. 1933. Game management. New York: Wildland Shrub and Arid Land Restoration Symposium, Charles Scribner’s Sons. October 19–21, 1993, Las Vegas, comps. B.A. ———. 1949. A Sand County almanac and sketches here Roundy, E.D. McArthur, J.S. Haley, and D.K. Mann. and there. New York: Oxford University Press. INT-GTR-315. Ogden, UT: USDA Forest Service, MEFFE, G.K., and C.R. CARROLL. 1994. Ecological Intermountain Research Station. restoration. In Principles of conservation biology, eds. ARONSON, J., S. DHILLION, and E.L. FLO’H. 1995. On G.K. Meffe and C.R. Carroll, 409–38. Sunderland, the need to select an ecosystem reference, however im- MA: Sinauer Associates. perfect: A reply to Pickett and Parker. Restoration Ecol- MICHENER, W.K. 1997. Quantitatively evaluating ogy 3:1–3 restoration experiments: Research design, statistical BRADSHAW, A.D. 1996. Underlying principles of restora- analysis, and data management considerations. tion. Canadian Journal of Fisheries and Aquatic Science Restoration Ecology 5:324–37. 53(suppl.1):3–9. MONTALVO, A.M., S.L. WILLIAMS, K.J. RICE, S.L. BUCH- BROWN, P.M., M.R. KAUFMANN, and W.D. SHEPPERD. MANN, C. CORY, S.N. HANDEL, G.P. NABHAN, R. 1999. Long-term, landscape patterns of past fire PRIMACK, and R.H. ROBICHAUX. 1997. Restoration events in a montane ponderosa pine forest of central biology: A population perspective. Restoration Ecology Colorado. Landscape Ecology 14:513–32. 5:277–90. CAIRNS, J. 1993. Ecological restoration: Replenishing PALMER, M.A., R.F. AMBROSE, and N.L. POFF. 1997. our national and global ecological capital. In Nature Ecological theory and community restoration ecology. conservation 3: Reconstruction of fragmented ecosystems, Restoration Ecology 5:291–300. global and regional perspectives, eds. D.A. Saunders, SHINNEMAN, D.J., and W.L. BAKER. 1997. Nonequilib- R.J. Hobbs, and P.R. Ehrlich, 193–208.Chipping rium dynamics between catastrophic disturbances and Norton, New South Wales, Australia: Surrey Beatty & old-growth forests in ponderosa pine landscapes of Sons. the Black Hills. Conservation Biology 11:1276–88. COVINGTON, W.W., and M.M. MOORE. 1994. Postset- SOCIETY FOR ECOLOGICAL RESTORATION (SER). 1994. tlement changes in natural fire regimes and forest Definitions, definitions, definitions. SER News 7:5. structure: Ecological restoration of old-growth pon- STONE, J.E., T.E. KOLB, and W.W. COVINGTON. 1999. derosa pine forests. In Assessing forest ecosystem health Effects of restoration thinning on presettlement Pinus in the inland West, eds. R.N. Sampson and D.L. ponderosa in northern Arizona. Restoration Ecology Adams, 153–81. New York: Haworth Press. 7:172–82. COVINGTON, W.W., P.Z. FULÉ, M.M. MOORE, S.C. HART, T.E. KOLB, J.N. MAST, S.S. SACKETT, and M.R. WAGNER. 1997. Restoring ecosystem health in pon- derosa pine forests of the Southwest. Journal of For- estry 95:23–29. Michael R. Wagner (e-mail: mike.wagner@ DEVIVO, M.S. 1991. Indian use of fire and land clear- nau.edu ) is Regents Professor, School of ance in the southern Appalachians. In Fire and the en- Forestry, Northern Arizona University, vironment: Ecological and cultural perspectives, eds. S.C. Nordview and T.A. Waldrop, 306–10. Asheville, Flagstaff, AZ 86001; William M. Block NC: USDA Forest Service. is research wildlife biologist and Brian W. ———. 1992. A landscape interpretation: Eastern Geils is research pathologist, USDA For- North America in 1492. Carver Interdisciplinary Jour- est Service, Rocky Mountain Research nal 10(1). Station, Flagstaff; and Karl F. Wenger is DOBSON, A.P., A.D. BRADSHAW, and A.J.M. BAKER. 1997. Hopes for the future: Restoration ecology and past-president, Society of American For- conservation biology. Science 277:515–22. esters, Tappahannock, Virginia.

Journal of Forestry 27