1
Introduction

"Nothing is inexhaustible but the wealth of nature."

—R.W. Emerson

Assemblages of plants, animals, and microorganisms increasingly compete with an expanding human population and its rising economic aspirations and associated environmental demands for a broad range of resources in and products from the natural world. That simplified overview frames a pressing need to address and minimize such conflicts. Controversy is often generated by management decisions that have either beneficial or adverse consequences for biological diversity. The nationwide debate over changes in forest management in the Pacific Northwest to protect the spotted owl and its associated ecosystems and the global controversy over the costs and benefits of deforestation in the Amazon are cases in point. Such controversies often arise over differing opinions on the relative importance or value of the organisms at risk in relation to the economic value of the developmental or recreational activities in question. It is natural to believe that improving the methods of valuing the costs or benefits of changes in biodiversity can reduce disagreements over the values and enhance both the process and the results of resource-management decision-making.

Dietz and Stern (1998) identify factors that contribute to conflicts over biodiversity management. First, biodiversity is multidimensional; decisions about it will have many effects, and people will be affected in different ways. Second, decisions about biodiversity involve considerable scientific uncertainty: our general knowledge of the structure and function of ecosystems is incomplete, and we rarely have enough information on the local circumstances that will be influenced by management decisions. Third, values might be in conflict, and which values will be affected by a decision can be as uncertain as the science. Fourth, managers might not be trusted by the public or by segments of it. Fifth, there is usually considerable urgency in making decisions, because taking no action or continuing current policy is highly consequential.



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1 Introduction "Nothing is inexhaustible but the wealth of nature." —R.W. Emerson Assemblages of plants, animals, and microorganisms increasingly compete with an expanding human population and its rising economic aspirations and associated environmental demands for a broad range of resources in and products from the natural world. That simplified overview frames a pressing need to address and minimize such conflicts. Controversy is often generated by management decisions that have either beneficial or adverse consequences for biological diversity. The nationwide debate over changes in forest management in the Pacific Northwest to protect the spotted owl and its associated ecosystems and the global controversy over the costs and benefits of deforestation in the Amazon are cases in point. Such controversies often arise over differing opinions on the relative importance or value of the organisms at risk in relation to the economic value of the developmental or recreational activities in question. It is natural to believe that improving the methods of valuing the costs or benefits of changes in biodiversity can reduce disagreements over the values and enhance both the process and the results of resource-management decision-making. Dietz and Stern (1998) identify factors that contribute to conflicts over biodiversity management. First, biodiversity is multidimensional; decisions about it will have many effects, and people will be affected in different ways. Second, decisions about biodiversity involve considerable scientific uncertainty: our general knowledge of the structure and function of ecosystems is incomplete, and we rarely have enough information on the local circumstances that will be influenced by management decisions. Third, values might be in conflict, and which values will be affected by a decision can be as uncertain as the science. Fourth, managers might not be trusted by the public or by segments of it. Fifth, there is usually considerable urgency in making decisions, because taking no action or continuing current policy is highly consequential.

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In the face of such complexity and the sometimes fierce conflict that attends it, managers need the best available information and tools. This report responds to a request to the National Research Council from the Department of Defense (DOD), which recognized that many of the lands that it owns or controls have potentially high value for the protection and maintenance of biodiversity. The primary purposes for which these DOD lands are managed requires that they be held in relatively large blocks and that they not be developed for commercial or residential uses. Although the military uses affect natural conditions, often much of the lands remain relatively free of major impacts on biodiversity. The Committee on Noneconomic and Economic Value of Biodiversity in the Board on Biology of the National Research Council's Commission on Life Sciences was charged with examining "how current scientific knowledge about the economic and noneconomic value of biodiversity can best be applied in the management of biological resources" (see appendix A, "Statement of Task"). This report reviews current understanding of the value of biodiversity and the methods that have been developed to assess that value in particular circumstances. Although not denying that improved methods of valuation can aid decision-making, the committee and its report have focused on a more fundamental challenge. Specifically, important differences in opinion about decisions regarding biodiversity are likely to arise from differences in the ethical frameworks that people use to value biodiversity. The most precise economic analysis showing that a housing subdivision will generate greater economic benefit for society than the protection of a nature reserve will hold relatively little sway over the views of a person who believes that it is morally wrong to cause the extinction of a species that is found only in that nature reserve. As much as managers might like to simplify decision-making processes to a straightforward assessment of economic costs and benefits, the reality of the most important decisions that our society faces is far more complex. Wise decisions regarding social goods are made by weighing a variety of legitimate measures of importance or value. This report differs from many recent ones that have focused solely on measures of the economic value of biodiversity in that it seeks to embrace the range of value frameworks that legitimately can be used to determine the merits of alternative courses of action regarding biodiversity. Recognizing that improved methods can enhance the process of decision-making within any framework for assigning value, we also provide a summary of state-of-the-art methods for establishing value. But we focus even greater attention on methods for weighing input from stakeholders with different frameworks for determining the value of different actions to yield sound resource-management decisions. The wide range in the kinds of values that people attribute to maintaining biodiversity and in the basic philosophies that lie behind these values led to the committee's conclusion that the processes making decisions involving biodiversity are of greater importance than the techniques that assign values to any one of the philosophical postures. Choosing the appropriate decision process has two

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goals. One is to shed light on how protection of elements of biodiversity affects the various kinds of values that it affords. The other is to build the confidence not only of the resource mangers, but also of the public, in the ultimate decisions. Resource managers have the unenviable task of weighing the value of biodiversity in the absence of any one suitable metric that encompasses the range of legitimate views. Appropriate processes thus become important for identifying how possible management choices affect biodiversity for identifying how these choices affect the various kinds of values that can be assigned to biodiversity and for gaining public acceptance of the decisions made by the resource managers. Our intent has been to provide a spectrum of examples that embody a range of complications and challenges inherent in environmentally sensitive management decisions. We have purposely constrained our examples to illustrate more local than global issues. Thus, we avoid discussion of global warming and its potential consequences; although surely important enough in connection with the central themes of our report, these are beyond the capacity of local managers and decision-makers to influence significantly. Rather, we present and discuss scenarios ranging from specific local actions to regional problems that, although acknowledged, remain unsolved. These are intended to encapsulate the multiple dimensions of the management challenge; we do not intend them to be interpreted as specific instructions. Management flexibility and development of mutual trust and understanding are likely to achieve management objectives more effectively than the blunt application of a legal procedure. We begin by describing in some detail two examples that approach the extremes of the management dilemma. The Camp Pendleton case study involves a spatially restricted program of environmental management sensitive to the maintenance of the local biological communities. The Western Rangelands case study embodies a nearly polar opposite; the management challenges are diverse, the spatial scale is immense, there is little evidence of problem solution, and there surely is no single solution. These examples are given to establish the biological, economic, and even philosophical issues central to our report. Case Study: Camp Pendleton Camp Pendleton, a 126,000-acre Marine Corps training base along the Pacific Coast between Los Angeles and San Diego, has almost by accident become a biodiversity reserve in the midst of exploding residential development. The base has a diversity of habitat types in an area of high natural biodiversity and includes a number of species of special concern, especially threatened and endangered species, such as the California gnat-catcher, the least Bell's vireo, the orange-throated whiptail lizard, and the arroyo toad. Its amphibious-warfare training mission, which might seem to be at odds with protecting biodiversity, actually treads lightly on the natural setting, which is dominated by grassland and

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coastal sage scrub and includes extensive areas of chaparral and oak woodland and increasingly rare riparian zones. Because it is the only amphibious military training center on the West Coast, the Department of Defense has a particular interest in keeping Camp Pendleton. But, the military is increasingly recognizing the values of biodiversity on its many relatively undeveloped bases around the country. Weighing against those interests is the potentially high development values of some bases. Land values in the Camp Pendleton area are especially high, because of its setting as one of the most rapidly urbanizing regions in North America. One result of the high interest in Camp Pendleton was the formation of the Biodiversity Research Consortium, which involves, among other organizations, the USDA Forest Service, the Harvard University School of Design, Utah State University, the University of California, and The Nature Conservancy. The consortium's study (Steinitz and others 1996) of the Camp Pendleton region includes all of the camp and the immediately adjacent terrain, a zone of 50 by 83 miles that encompasses five river basins, two zones of coastal drainage, and parts of San Diego, Riverside, and Orange Counties. The reasons for choosing this area for the intensive study included the conflict and controversies inherent in the adjoining region; the likelihood of dramatic changes in the region resulting from rapid population increase of about 300,000 to 2 million by 2010; and the possibility that a policy study might make a difference with respect to the conservation of biodiversity in the region. The camp and immediately adjacent areas in the inland mountains to the north and east of it, such as the San Mateo Canyon Wilderness area of the Cleveland National Forest and The Nature Conservancy's Santa Rosa Plateau Reserve, are perceived by neighbors as a regional preserve for biodiversity. Among the factors entering into the study's policy planning were hydrology (the camp is subject to infrequent but devastating floods), fire frequency and predictability, slope occupancy (many parts of the region have slopes that exceed 10 to 15%), and biodiversity conservation. Biodiversity has been examined from three perspectives: total biodiversity, measured simply by numbers of species (biodiversity in the region is the highest in California; 345 vertebrate species in the region constitute 60% of the total in the state); 11 selected vertebrates species of special concern (for example, endangered species); and the diversity of landscapes and the pattern of their distribution. The Biodiversity Research Consortium's study (a geographic information system study involving multiple layers of analysis and more than 10 gigabytes of data) led to the development of four specific strategies for development and seven alternative patterns. The strategies have different implications for biodiversity conservation and for preservation of the main features important to military planning on Camp Pendleton. A major outcome of the study is the recognition that efforts to concentrate regional development in specific areas would make it possible to meet military

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and biodiversity conservation goals in the long run. It is crucial that housing and commercial development avoid slopes in excess of about 10–15% and flood plains. Those two limitations in combination will, however, preserve most of the biodiversity in the region and will preserve the militarily important elements of Camp Pendleton. A fundamental assumption is that the integrity of the boundaries of the camp be maintained and that development on the Santa Rosa Plateau occur in such a manner as to maintain an effective wildlife corridor between the camp and other relatively natural areas. The study also concluded that there is a window of opportunity of 2 years to about 10–15 years during which critical decisions must be made by Camp Pendleton, regional planning authorities in the three counties, and the Nature Conservancy. During this window, such issues as the integrity of the military mission, transferring military lands to nonfederal entities for biodiversity conservation, planning for development that recognizes the limitations imposed by steep slopes and flood plains, fire management, flood control, and appreciation of the importance of biodiversity will be central in the decision-making process. There is also a growing appreciation of the relation between natural beauty as perceived in landscapes and biodiversity conservation–a mix that is especially well exposed in coastal southern California. The Camp Pendleton case study illuminates many of the complicated interactions involved in how different means of valuing biodiversity enter into planning processes. For the military, maintenance of the status quo is important. Accordingly, camp personnel make certain that federal laws are enforced. With respect to biodiversity, the most important laws are related to endangered species and pollution. The military also wants to be a good neighbor and understands that its open space is valued by a sizable proportion of the southern California populace, not only for the organisms that it contains but also as landscape. Important issues related to biodiversity involve fire and flood control, maintenance of riparian and upland habitat corridors for wildlife movements, and maintenance of open space. Regional governments envision Camp Pendleton as an important component of regional planning, but the camp does not want to be viewed as a wildlife park when it has its own needs for future development. Values placed on biodiversity by the public in the form of laws and activities of interested individuals and organizations are important components of all aspects of planning and development on the base; the USDA Forest Service and The Nature Conservancy own lands that either abut or are very near Camp Pendleton boundaries. The camp is also concerned that upstream land development is contributing to increased frequency and intensity of floods and increasing the likelihood of wildland fires. In a complicated situation like the one that Camp Pendleton presents, biodiversity values play important roles in all aspects of local and regional planning and development. Chapters 2, 3, and 4 discuss how biodiversity can be valued. In sum, this case illustrates some of the complicated interactions in matters

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that are involved in maintaining and protecting biodiversity. But it provides little guidance on how to value biodiversity in this or similar situations and on how the parties to such resource-management decisions can be involved in the valuation process. It does point to the need to make such decisions in the context of the region within which islands of biodiversity, such as Camp Pendleton, exist. Case Study: Western Rangelands Livestock grazing is by far the most widespread land use in the American West, and it has a major impact on the biological diversity of the region. About 70% of the land area of the 11 western states is grazed (DOI 1994), mostly on federal lands managed by the Bureau of Land Management and the USDA Forest Service (Fleischner 1994; Saab and others 1995). This case study illustrates the challenges in developing consensus about the values of biodiversity over such a large geographic area. A relatively small number of ranchers with direct commodity interests in the land are pitted against a much larger number of conservationists and recreationists with less-direct interests in the value of the native biodiversity of the same land. The economic significance of public-lands grazing, despite its near ubiquity in the West, is relatively minor on a national scale. Nevertheless, western rural cultures and economies would be substantially affected if it were to be halted. Any conservation-based modifications of present grazing policies must be based on sound information about their actual ecological consequences if the issue is to be resolved (Fleischner 1994; Vavra and others 1994). The following points are particularly relevant: Grasslands in the Great Plains are relatively tolerant of ungulate grazing because of their evolutionary associations with the continent's principal native grazer, the bison (Bison bison) (Mack and Thompson 1982; Milchunas and others 1988). In contrast, grasses of the intermountain West and Southwest have had little association with native grazing ungulates and are relatively intolerant of livestock activities. Riparian habitats are scarce in the West, are very rich in biomass and biological diversity, and are strongly affected by livestock grazing (DOI 1994; Elmore and Kauffman 1994; Johnson and Jones 1977; Platts and Nelson 1985; Saab and others 1995). The water-holding capacity of arid lands in the West has been severely altered by heavy livestock grazing to the extent that many streams that once flowed perennially today flow only violently and sporadically (Sheridan 1981). The value of restored rangelands as watersheds might exceed their value for livestock production in purely economic terms (for example, Cox and others 1984). The introduction of nonnative grasses and forbs, often intended to improve livestock grazing, has had major negative effects on endemic flora and

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fauna of western rangelands (for example, Bock and others 1986; D'Antonio and Vitousek 1992; Mack 1981). Livestock grazing has caused soil compaction and destruction of soil microbiotic crusts, and these have drastically altered the structure and function of the rhizosphere, especially in areas lacking an association with native ungulates (Fleischner 1994). Control and elimination of native predators (such as wolves, Canis lupus) and livestock-competing herbivores (such as prairie dogs, Cynomys ludovicianus) have reduced the biological diversity and altered the structure and function of many western ecosystems (for example, Fleischner and others 1994; Miller and others 1994). In most western ecosystems, livestock grazed at economically meaningful levels probably operate as keystone species by determining which components of the endemic flora and fauna will thrive and which will not. Given the near ubiquity of livestock in much of the West, it is the plants and animals that are intolerant of the activities of large, hoofed, grazing mammals that have relatively few places left to live. The issue of the future of the federal rangelands has been polarized by absolute statements about the positive or negative effects of livestock grazing on biological diversity (for example, Ferguson and Ferguson 1983; Jacobs 1991; Savory 1988). Scientific opinion on the livestock-grazing issue remains polarized between ecologists who argue for livestock removal (for example, Fleischner 1994) and range scientists who argue that moderate grazing is not only acceptable but often a necessary tool for maintaining healthy rangeland ecosystems (for example, Vavra and others 1994). Conservation organizations and ranchers are deeply divided on the issue, and lobbying organizations representing both groups usually exaggerate and exacerbate the division. Federal land managers are caught in the middle of the controversy. The present conflict over the future of the western rangelands might have been inevitable, given their declining economic value for livestock grazing and the growing recognition of its effects on the ecological integrity and biological diversity of arid grasslands. But there is little likelihood that livestock grazing will cease on public rangelands in the near future (Brussard and others 1994). Most attempts to resolve the conflict over use of the western rangelands have failed, but good ecological analysis could lead to at least partial resolution of the conflict if the results of the analysis were accepted by the parties involved. What has been lacking so far is adequate forums for reaching agreement among the parties to the conflict on the facts and values that are involved. Such forums should be constituted to recognize subregional differences in biological conditions (for example, the differences in evolutionary development of the Great Plains and intermountain rangelands relative to current livestock grazing) and in values—both the values of biodiversity and the values generated by use of the

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rangeland resources. Chapter 6 presents some examples of such forums. Resolving the conflict over use of these rangelands might require both action by Congress and management changes that are sensitive to the many relevant differences at the local level. The Committee and Its Report The issues addressed in this report require bringing together a variety of value perspectives, disciplinary skills, and decision processes. Melding these at levels from broad policy decisions, such as passing legislation to protect endangered species or habitats, to on-the-ground management decisions, such as guiding development in a small wetland, will be difficult. This report offers no simple answers that will fit equally the full extent of the kinds of decisions that will be involved. Other federal agencies and many state natural resource agencies also have lands held in large blocks where biodiversity can be protected and maintained. The federal agencies include the US Department of the Interior National Park Service, Fish and Wildlife Service, and Bureau of Land Management and the US Department of Agriculture Forest Service. Each of these agencies has resource uses mandated by law that might affect biodiversity, but each also sharply limits development other than that associated with resource use. Taken together, these federal agencies, including DOD, and the state natural-resource agencies provide a major opportunity for protection and maintenance of biodiversity. These large tracts of state and federal lands, including military reservations, collectively identify a developing national system of potential biodiversity reserves. Their importance aesthetically, economically, and biologically should not be undervalued. The committee's conclusions are not limited in their implications for protecting and maintaining biodiversity to federal and state natural-resource agency lands, but extend as well to other resource lands and management situations. At the same time, the extent and relatively undeveloped character of the federal and state natural-resource agency lands, along with the laws and policies that guide management of these lands, have shaped the committee's perspective. Some of these laws (for example the Endangered Species Act) are related to elements of protecting biodiversity. Others concern the processes for making public decisions. But these matters affecting publicly owned lands do not reduce the opportunities for protecting and maintaining biodiversity on other lands, at which this report is also aimed. The report is the product of a committee of specialists in relevant scientific fields. Just as the kinds of decisions involving valuation of biodiversity vary in scale and range, the disciplinary perspectives about valuing biodiversity vary. We provide information to aid managers in understanding and responding to conflicts that arise about biodiversity as a basis for decisions when tradeoffs must be made. Even the best analytical tools cannot resolve all conflicts, but we

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believe that an understanding of the limits and benefits of analytical and other approaches will aid managers in doing their job better. In chapter 2, we review the character of biodiversity, emphasizing the differing dimensions involved. Both because these dimensions range from genes to biologically integrated ecosystems and because management decisions must be sensitive to the differing spatial and temporal scales involved, strategies for management and conservation must be clearly defined. We have chosen only to touch on some of the more quantitative techniques available to assess the status of populations or habitats. We adopted this stance because the statement of task focuses on the concept of value: a species's status need not be linked directly to its economic value, although it might well be linked to its noneconomic value. Consideration of the challenge of applying ecological criteria, which must underlie determination of status, to the socioeconomic perspectives central to value is delayed to chapter 6. However, the complexity of their interplay is apparent in most of the case studies. Managers must be aware of the multifaceted nature of biodiversity that occurs across different spatial and temporal scales, and analyses must consider a wide range of potential alternatives and impacts. Chapter 3 reviews some previous efforts to assign monetary values to contributions of biodiversity to society. These include instrumental values of contributions to human food, fiber, and recreation and to social and cultural well-being. The exact numbers provided cannot be transferred to contexts other than those for which they were developed. The reader must be constantly aware that many aspects of biodiversity have value and that although some values can be substantial, often they cannot be accurately captured or quantified. Managers need to be aware that values other than those specifically identified might—probably do—exist and that conflicts can arise if resource extraction is the only alternative considered. For example, some species have long-line lineages and deserve special reverence for their long evolutionary history and what we can learn from them. Aspects of biodiversity that express our nation's history and character as distinct from our individual consumer wants do not fit easily into a formal analytical framework (such as benefit-cost analysis), but they are often of central importance to land managers. Advocates for biodiversity conservation often will be motivated by such public value concerns, which form a core part of the American social fabric that resource managers must weigh against instrumental benefits. Thus, the current political debate about values in American society is often not about prices and price shifts as much as it is about the things that Americans deem important. The Western tradition of scholarship has offered some systematic ways of thinking about values and value conflicts. Chapter 4 describes the major systematic normative positions in philosophy. Some of these traditions offer explicit suggestions about how humans might relate to conflicts about biodiversity; in others, the application to biodiversity is less clear. This material is relevant to

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resource managers in that, although it deals with venerable traditions, they describe logical ways of thinking about value conflict. Managers must be aware that there are numerous alternative systematic and well-reasoned ways to approach the valuing of biodiversity and that each tradition suggests what should be given weight in a policy decision and how a decision should be reached. Differing policy-analysis tools implicitly or explicitly draw on those traditions and thus favor particular outcomes. Some of the conflicts faced by managers grow from the concerns of ''winners'' and "losers" related to different policy outcomes. But many of the conflicts result from differing traditions of thinking about value and the approaches to making decisions that follow from them. In the field of risk analysis, some literature suggests that there are shared differences between federal officials and various stakeholders in their explanations of why environmental conflicts arise (Dietz and others 1989). Obviously, differences among parties in understanding why there is conflict can impede resolution of conflict. Given all those concerns, how is a manager to proceed? No tool or approach is likely to resolve all conflicts to the satisfaction of all parties. In chapter 5, we review some of the ways that economists assign values for improving the decision-making process, as well as their usefulness and limitations. Economic tools are generally used to estimate the effects of incremental changes, so economists tend to focus their attention on aspects of biodiversity and values in scales similar to those of markets for other goods and services. That is, economists typically direct their skills and analytical tools at decisions involving relatively small changes, such as changes in the supply and price of milk, rather than in the value of milk to the nation's overall well-being. Methods like benefit-cost analysis provide useful information, but they can rarely be the sole basis for a management decision. At the same time, by quickly identifying weaknesses, they can be helpful in eliminating some forms of undesirable options from further consideration. Chapter 6 addresses processes that resource managers can use to determine public concerns, identify alternative management approaches, obtain information from stakeholders and the public about values related to the alternatives, and identify alternatives that best meet all needs. It provides guidance on how the valuation of biodiversity and the process of weighing values of biodiversity can be used to improve policy formulation and management decision-making. Chapter 7 stresses that it is important for managers to have a broad perspective on how conserving biodiversity fits into their management decisions. No single suitable approach to valuing biodiversity can be recommended. As managers struggle with their difficult resource-management decisions, continued effort should be made to improve information on how management affects biodiversity, to improve the integration of the various values that are relevant to conserving biodiversity, and to improve processes for reaching consensus on management decisions.

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