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Drafting a Conservation Blueprint
A Practitioner's Guide to Planning for Biodiversity
By Craig R. Groves ISLAND PRESS
Copyright © 2003 Craig R. Groves and The Nature Conservancy
All rights reserved.
ISBN: 978-1-59726-942-1
CHAPTER 1
The Challenge of Conserving Biological Diversity
Still, too many land conservation efforts are haphazard and reactive in nature. They deal with whatever comes over the transom. The result is haphazard conservation and haphazard development. —MARK BENEDICT AND EDWARD MCMAHON (2002)
Seventeen and a half billion dollars—that is the amount state and local governments in the United States alone directed toward open space preservation from 1999 through 2001 (Benedict and McMahon 2002).Yet much of this money has not been spent wisely from a conservation perspective. According to Benedict and McMahon, the authors of a recent report on "green infrastructure," smart land conservation of the future needs to be more proactive and less reactive, more systematic and less hap-hazard, multifunctional and not single-purpose, and larger in spatial scale.
Achieving smarter conservation in the future will be challenging, in part because many important decisions about land and water conservation are made locally, especially with regard to privately owned lands. All over the world, local governments, from counties and provinces to cities, townships, and villages, make decisions every day about land use. These decision makers, through no fault of their own, have a limited view of the world, usually defined by political boundaries of their particular jurisdiction. Unfortunately, the natural world does not operate along these geopolitical lines. Most species, ecological communities, and ecosystems depend upon a much larger domain for their long-term survival. The result has been what could only be described as the "tyranny of the local." Lacking information with which to make better decisions, local governments, often unwittingly, reach conclusions that result in the degradation or destruction of some of the best remaining examples of the world's ecosystems (Dale et al. 2000). Clearly, many important decisions about natural resources are also made at levels above local government. Natural resource agencies at the state or national level, although usually operating at larger spatial scales, are guilty as well of planning along inappropriate boundaries and making poorly informed decisions. Taken as a whole, incremental decisions, from the local to the national level, often result in driving species to the edge of extinction—and even over the edge.
What we need are a road map and appropriate planning boundaries for making more informed decisions, decisions that benefit the natural world and, in turn, through the services nature provides, the human world. That is what this book is about—developing regional-scale road maps or plans that, if implemented, will help ensure that the world's species, communities, and ecosystems, and the underlying ecological processes that sustain them, will not only persist, but continue to evolve and adapt for generations to come. To devise such a road map, this book lays out a step-by-step planning process for conserving the biological diversity of entire regions. To best appreciate the value of this planning framework, we first need to have a good understanding of what problems conservation planning is attempting to address, how biological diversity is best conceptualized and defined, and what contributions the disciplines of ecology and conservation biology can make to developing better planning processes and credible conservation plans.
The Biological Diversity Problem
Over 3500 vertebrate species, nearly 2000 invertebrate species, and over 5600 species of plants from around the world made the 2000 IUCN Red List of Threatened Species (Hilton-Taylor 2000). All these species face a high risk of extinction in the wild. In the United States alone, the number of species listed as Threatened or Endangered under the Endangered Species Act (ESA) has increased sixfold from 174 in 1976 to 1244 species as of November 2001 (http:endangered.fws.gov, U.S. Fish and Wildlife Service). These ever-lengthening lists of threatened and endangered species worldwide are symptomatic of an even more serious problem—the extinction crisis—whereby species are currently going extinct at a rate conservatively estimated to be 100 to 1000 times greater than rates recorded through recent geological time (Lawton and May 1995). Furthermore, the extinction crisis is likely worse than the current data indicate. Recent studies suggest that today's fragmentation and destruction of natural habitats may result in extinctions that will not be apparent to us for several generations, creating what has been termed an "extinction debt" (Tilman et al. 1994).
The principal causes of this march toward extinction are well documented (World Resources Institute, World Conservation Union, and United Nations Environment Programme 1992, Noss and Cooperrider 1994, McNeely et al. 1995,Vitousek et al. 1997).They include the conversion and fragmentation of natural habitats, the introduction of non-native species, pollution, the direct exploitation of species, the disruption of natural ecological processes, industrial-scale agriculture and forestry, climate change, and overall human domination of Earth's ecosystems. Habitat loss, primarily from urbanization and agriculture, is the single largest cause of species endangerment (Wilcove et al. 1998, Czech et al. 2000, Hilton-Taylor 2000). Although the ESA has been an effective piece of legislation for abating the rate of extinction in the United States, it is largely a reactive tool, used only for species that are already well down the road to critical levels of endangerment. Too often, ESA implementation results in situations popularly described to the media by former U.S. Secretary of the Interior Bruce Babbitt as environmental "train wrecks" (Reid and Murphy 1995). An example close to my home in the Pacific Northwest demonstrated this point emphatically. Sockeye salmon (Oncorhynchus nerka) historically returned from the Pacific Ocean to spawn by the thousands in central Idaho, yet they were not listed as Threatened or Endangered until their returning numbers were reduced to less than ten individual fish.
By itself, single-species approaches such as the ESA are necessary but insufficient tools for effectively addressing the extinction crisis and stemming the tide of overall losses of biological diversity worldwide. Entire ecosystems are being lost at alarming rates (World Conservation Monitoring Centre 1992). Hardly a day passes without reports about the dire status of the world's coral reefs, wetlands, or tropical forests. The "homogenization" of many ecosystems through the spread and invasion of non-native species is a serious issue in itself, as it complicates efforts to conserve biological diversity. These points corroborate the notion that conservation actions, to be successful, need to operate at multiple levels of biological organization, from populations and species to landscapes and ecosystems.
Poor planning in the identification of important areas for conserving biological diversity has exacerbated the extinction crisis. Most areas in the world that have been designated for conservation purposes were set aside in an ad hoc manner, and not specifically for conserving biological diversity (Pressey 1994). Recent analyses in the United States (Scott et al. 2001a) and Australia (Pressey et al. 1996a, Mendel and Kirkpatrick 2002) have shown that the locations of areas set aside for conservation are strongly biased toward the most unproductive soils, the steepest slopes, and the highest elevations. Similar trends exist for many other parts of the world (Scott et al. 2001b). One of the most oft-cited examples of this trend is the "rocks and ice" national parks of the western United States, many of which were established for their scenic grandeur in the Rocky Mountains, Sierra Nevadas, or Cascade Mountain ranges, but as a whole are poorly representative of the region's different ecosystems. Conversely, other recent analyses on the distribution of endangered species and threatened habitats in the United States and elsewhere have shown that the majority of endangered species, and, indeed, the majority of biological diversity (as measured by the number of species), tends to occur in lower elevations, warmer climates, and coastal areas that are more attractive to human occupation and use (Dobson et al. 1997, 2001).
Natural resource managers, conservation practitioners, and scientists from around the globe have recognized the serious nature of the problems that must be addressed to effectively conserve biological diversity, and they have reacted to these problems on several fronts. Several examples of these reactions are noted here. First, in June 1992, at the United Nations Conference on the Environment and Development in Rio de Janeiro (also known as the Earth Summit), a record 150 countries signed a global Convention on Biological Diversity (CBD), a landmark treaty that takes a comprehensive approach to the conservation and sustainable use of Earth's biological resources (Glowka et al. 1994).This treaty has already had a significant conservation impact globally, and it has potential for substantial influence in the future (see the section on the CBD later in this chapter). Second, the World Conservation Monitoring Centre (1992) compiled the first global review and sourcebook on biological diversity. Third, the United Nations Environment Programme (1995) commissioned and published the Global Biodiversity Assessment to provide a state-of-the-art understanding of society's knowledge of biological diversity and the nature of human impact upon this diversity.
Fourth, a renowned group of scientists from agencies, academia, and nongovernmental organizations met in a workshop in 1995 sponsored by the U.S. Marine Mammal Commission and issued a set of seven conservation principles along with guidelines for their implementation (Mangel et al. 1996). Aimed at natural resource managers, some of the important principles included maintaining biological diversity at genetic, species, population, and ecosystem levels; assessing the ecological and sociological effects of resource use before both proposed use and proposed restriction; using the full range of knowledge and skills from the natural and social sciences to address conservation problems; and understanding and taking into account the motives, interests, and values of all users and stakeholders.
Finally, recognizing that habitat loss and degradation are the leading culprits in the loss of diversity and that many decisions resulting in such losses occur at a local level, the Ecological Society of America issued a set of guidelines to better inform local land-use decision making (Dale et al. 2000). Among the guidelines were examining the impact of local decisions in a regional context, planning for long-term change and unexpected events, preserving rare landscape elements and associated species, retaining large contiguous or connected areas that contain critical habitats, avoiding the introduction of exotic species, and avoiding or mitigating for negative effects of development on ecological processes.
In the chapters ahead, I will explore each of these principles and guidelines, and others in more detail, as I develop a comprehensive planning framework for conserving biological diversity. But before doing that, we need to examine more closely what is meant by the term biological diversity or its shortened form, biodiversity. An important part of the challenge to conserving biological diversity is getting society to better understand and appreciate the concept.
Biodiversity: Definition, Perceptions, and Values
Popularized by the scientific community over the last 15 years, biodiversity and its conservation have been the focus of numerous books, notably those by Harvard biologist E. O. Wilson (e.g., Wilson 1992). Not surprisingly, a variety of definitions for biodiversity have been advanced (see review by Baydack and Campa 1999). Early definitions focused nearly exclusively on the diversity or variety of life-forms or living organisms. In practice, many biologists have interpreted this to mean that areas with high levels of biodiversity have relatively high numbers of species. In part, this interpretation of the term has led to an emphasis on conserving biological diversity in the world's tropical regions that harbor the vast majority of described species on Earth. More recent definitions view biodiversity as the variety of living organisms, the ways in which they organize themselves (genes, populations, species, communities, ecosystems), and the ways in which they interact with the physical environment and with one another (Redford and Richter 1999).
Whether biodiversity is actually defined primarily as the variety of living organisms, or whether it also includes the ways these organisms organize themselves and interact with the environment, makes little difference from a theoretical standpoint. However, from a practical standpoint of conserving biodiversity, it matters a great deal. To actually conserve biodiversity, natural resource managers and conservation biologists must pay attention to its three components (Noss 1990, Redford and Richter 1999): composition, structure, and function (Figure 1.1). From this point of view, the definition offered by Redford and Richter (1999) is preferable to definitions that focus solely on numbers of species. Composition refers to the identification of elements within the different levels of biological organization, from genes and species to communities and ecosystems. The description of a particular area of tropical forest that harbors 400 species of birds is a reference to the composition of biological diversity at that site. Structure refers to how these different biological elements are physically organized. For example, walking through a stand of trees, we might observe some bird species on the forest floor, others in shrubs and trees of the forest understory, and still others high in the forest canopy. These different places within the forest describe the structure of biological diversity. Function refers to ecological processes that sustain composition and structure. Many forest types, for example, need periodic disturbances from natural fires or storm events to maintain structure and initiate reproduction.
In addition to having components of composition, structure, and function, biological diversity occurs at different spatial scales. The renowned ecologist Robert Whittaker (1975) first advanced this notion. He termed these scales alpha, beta, and gamma (Figure 1.2). Alpha diversity refers to the number and types of species that occur at a particular site or area. For example, at La Selva Biological Station in the Atlantic Forest lowlands of Costa Rica, a wide variety of bird species can frequently be observed. If one treks upslope from La Selva toward the continental divide of Costa Rica, different types of bird species and plants can be observed along the way. High on the divide itself, which is characterized by the cloud forests of Braulio Carrillo National Park, even the most casual naturalist would again observe the changes in bird and plant composition. These changes or turnover in species composition along a gradient, such as an elevational one, are referred to as a measure of beta diversity, or between-area diversity. The diversity of plants and birds encompassing this entire landscape, from the coastal lowlands to continental divide, is collectively known as gamma diversity. In many sites around the world, alpha diversity is actually increasing from the spread of non-native species, while beta and gamma diversity are generally declining.
Anyone who has hiked in the Rockies, Himalayas, Andes, or Alps, or in other mountain ranges with relatively rapid changes in relief, has likely made similar observations. The concept of beta diversity is especially important from a conservation standpoint. In areas with high turnover in species composition, such as many tropical forests, more intensive conservation efforts may be required than in regions where species are more broadly distributed. I will explore this concept and its ramifications for conserving biological diversity in more detail in later chapters.
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Excerpted from Drafting a Conservation Blueprint by Craig R. Groves. Copyright © 2003 Craig R. Groves and The Nature Conservancy. Excerpted by permission of ISLAND PRESS.
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