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Biodiversity and Development

We as a species are rapidly altering the world that provides our evolutionary and ecological context. The consequences of these changes are such that they demand our urgent attention. The large-scale problems of unprecedented population growth and inappropriate development are degrading the land, water, and atmosphere, and progressively extinguishing a broad array of the Earth's organisms and the habitats they inhabit. By downplaying these problems or putting them aside in favor of what seem to be more imperative personal, group, or national priorities, we are courting global disaster. By attending to them, we can begin to build a more stable foundation for lasting peace and prosperity.

We live in a world in which far more people are well fed, clothed, and housed than ever before. We also live in a world in which thousands of people, primarily women and young children in developing nations, die each day of starvation or of diseases related to starvation; in which human beings consume well over a third of total terrestrial photosynthetic productivity; and in which human activity threatens, over the next few decades, to eliminate a quarter of the world's species—species we may not use directly, but on which our survival depends in many other ways.

During the 1980s the total human population increased by about 0.8 billion people (from about 4.5 to 5.3 billion), or nearly 2 percent per year. If this rate of growth were to continue, human numbers would double in 39 years (PRB, 1989). If family planning programs and development activities are emphasized consistently and throughout the world, the human population could stabilize, according to United Nations estimates, at about 11 billion by approximately 2090. About 90 percent of this growth is likely to occur in the developing nations. Although population growth may not be the sole cause of environmental degradation, it is almost always an exacerbating factor and undermines the capacity of many developing countries, in particular, to conserve resources and meet basic human needs. As population pressures on



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Conserving Biodiversity: A Research Agenda for Development Agencies 1 Biodiversity and Development We as a species are rapidly altering the world that provides our evolutionary and ecological context. The consequences of these changes are such that they demand our urgent attention. The large-scale problems of unprecedented population growth and inappropriate development are degrading the land, water, and atmosphere, and progressively extinguishing a broad array of the Earth's organisms and the habitats they inhabit. By downplaying these problems or putting them aside in favor of what seem to be more imperative personal, group, or national priorities, we are courting global disaster. By attending to them, we can begin to build a more stable foundation for lasting peace and prosperity. We live in a world in which far more people are well fed, clothed, and housed than ever before. We also live in a world in which thousands of people, primarily women and young children in developing nations, die each day of starvation or of diseases related to starvation; in which human beings consume well over a third of total terrestrial photosynthetic productivity; and in which human activity threatens, over the next few decades, to eliminate a quarter of the world's species—species we may not use directly, but on which our survival depends in many other ways. During the 1980s the total human population increased by about 0.8 billion people (from about 4.5 to 5.3 billion), or nearly 2 percent per year. If this rate of growth were to continue, human numbers would double in 39 years (PRB, 1989). If family planning programs and development activities are emphasized consistently and throughout the world, the human population could stabilize, according to United Nations estimates, at about 11 billion by approximately 2090. About 90 percent of this growth is likely to occur in the developing nations. Although population growth may not be the sole cause of environmental degradation, it is almost always an exacerbating factor and undermines the capacity of many developing countries, in particular, to conserve resources and meet basic human needs. As population pressures on

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Conserving Biodiversity: A Research Agenda for Development Agencies land and other natural resources build, the intensity of natural disasters—especially flood and drought—can become aggravated, and the effects more tragic. There are other, more immediate causes of resource degradation in developing nations, including continuing military conflicts, misguided or misapplied policies that discourage conservation and, above all, persistent and crushing poverty—all of which leave people with few choices in managing land and natural resources. In the past, world leaders in both the developing and the developed nations have tried to address these essentially interrelated problems as separate phenomena. Other global concerns, such as climate change resulting from the buildup of greenhouse gases in the atmosphere, were regarded as separate issues—if they were regarded at all. Few recognized the fundamental need to consider environmental effects and prevent environmental degradation at all stages of development. Times appear to be changing. The level of concern among world leaders, including the international development agencies, has risen. Many are rethinking their priorities with respect to the allocation of resources to slow the degradation. Whether it is too late for leaders and development agencies to have a beneficial effect depends on what is done and how quickly. Furthermore, this new awareness comes at a time when dramatic political changes in the Soviet Union, Eastern Europe, Central America, the Middle East, and Africa are creating a competing demand for development resources. There are no easy choices, but there can be no turning back to the time when the short-term enrichment of human societies entailed the long-term impoverishment of the living world on which all societies depend. BIODIVERSITY: DEFINITIONS AND VALUES The diminishing of the Earth's biological diversity has consequences far more profound than other, sometimes more widely recognized, environmental dilemmas. Because the loss of biodiversity is irreversible—species that are lost are lost forever—the potential impact on the human condition, on the fabric of the Earth's living systems, and on the process of evolution is immense. Our species has evolved biologically and culturally in a highly diverse world. Our past interactions with other life forms have shaped our humanity in intricate ways, and our future cannot be separated from that of the other life forms with which we share the planet. Biological diversity refers to the variety of life forms, the genetic diversity they contain, and the assemblages they form. Biological systems, whether tundra, forests, savannahs, grasslands, deserts, lakes, rivers, wetlands, coastal communities, or marine ecosystems,

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Conserving Biodiversity: A Research Agenda for Development Agencies Definitions Biological diverssity (or biodiversity, as it has come to be called) refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from chemical structures that are the molecular basis of heredity to complete ecosystems. Thus, the term encompasses different genes, species, ecosystems, and their relative abundance (OTA, 1987). Species is the taxonomic category ranking immediately below genus; it includes closely related, morphologically similar, individual organisms that play a particular ecological role. Species diversity refers to the variety of different species. Genes represent the basic unit of inheritance, the strands of deoxyribonucleic acid (DNA) polymers that are found in the chromosomes in cell nuclei and control the genetic identity of individual organisms. Genetic diversity refers to the variety of genes. Species diversity normally refers to the diversity among species, whereas genetic diversity refers to the diversity within species. Ecosystem (derived from ''ecological system'') refers to the functional system that includes the organisms of a natural community together with their physical environment. Ecosystem diversity is the diversity among systems in a given area. Evolution is the process of change in the characteristics of organisms by which descendants come to differ from their ancestors. Biota refers to the collective plant, animal, fungal, and microbial life characterizing a given region. are functionally complex, and this complexity is associated, in often obscure ways, with the diversity of their component species. The direct benefits of biological diversity to humanity are myriad. We depend on animal, plant, fungal, and microbial species for food, fuel, fiber, medicines, drugs, and raw materials for a host of manufacturing technologies and purposes. The productivity of agricultural systems is a result of our continual alteration, over thousands of years, of once

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Conserving Biodiversity: A Research Agenda for Development Agencies wild plant and animal germplasm, and still rests on interactions of diverse organisms within agroecosystems. Genetic engineering, especially in the pharmaceutical and food-processing industries, uses natural genetic diversity from sources worldwide. Biomedical research requires comparative information on other species—models such as the mouse and the fruit fly. Although such direct values of biological diversity are not always reflected in market prices, they are more amenable than other values to economic analysis; hence, most economists have focused on this aspect of biological diversity. Beyond such direct values, biological diversity provides ecological services that are more difficult to calculate with precision. Living organisms are an important part of the processes that regulate the Earth's atmospheric, climatic, hydrologic, and biogeochemical cycles. Only in recent decades have we begun to understand the dynamics of these global processes, and discerning the functional role of biological diversity within them remains a fundamental and challenging question. This is especially important as we seek to understand how biological systems may affect, and be affected by, global climate change resulting from the emission of greenhouse gases into the atmosphere. It is easier to comprehend (and measure) the ecological services that biological diversity provides more locally in protecting watersheds, cycling nutrients, combating erosion, enriching soil, regulating water flow, trapping sediments, mitigating pollution, and controlling pest populations. As human activities alter landscapes and ecological processes on larger scales, the need for improved management and conservation of land, water, and marine resources will require greater understanding of ecosystem composition, structure, and function. The value of biological diversity in this sense is fundamental. Finally, ethical and aesthetic concerns direct us to respect, and strive toward rational stewardship of, the world's heritage of biological resources. The noneconomic, intangible, and inherent values of biological diversity take us beyond the traditional realm of the sciences, into the realm of the arts and humanities, language and history, religion and philosophy. These varied modes of human perception and expression have a fundamental stake in the fate of biological diversity, and must contribute to the determination of its fate. Although the values they embody may be less quantifiable, they are nonetheless real and pervasive. To regard biological diversity only for its tangible economic and instrumental values—even where these might be fully taken into account—paradoxically reduces its value. LOSS OF BIODIVERSITY The degradation of ecosystems throughout the world, but especially in warmer regions, has been well documented by scientists and is now

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Conserving Biodiversity: A Research Agenda for Development Agencies widely reported in the media. For example, tropical moist lowland forests, which until recently were the least disturbed terrestrial tropical communities, are now experiencing human exploitation on an unprecedented scale. These forests, which may contain more than half of the total species on Earth, have endured longer than other tropical ecosystems because they tend to be difficult to manage. (Deciduous forests, thorn scrub, and other plant communities in the tropics were decimated much earlier.) Their soils are relatively poor in nutrient reserves, often acidic, and subject to rapid leaching of nutrients under the high-rainfall conditions. This makes them relatively difficult to convert to intensive agriculture or forestry systems. Nonetheless, clearing for shifting cultivation, cattle ranching, timber, fuelwood, and conversion to perennial plantations has resulted in the accelerated loss and degradation of primary tropical moist forest. Large areas of the tropics have already been affected. Left unchecked, most of the forests will be entirely lost or reduced to small fragments by early in the next century. The loss of tropical forest cover can have far-reaching effects, including changes in regional climate (especially rainfall) patterns, changes in biological productivity, accelerated rates of soil erosion, disruption of watershed stability, and increasing emissions of green-house gases (which further affects global climate dynamics). In terms of biological diversity, the destruction of primary tropical moist forests causes the extinction of vast numbers of species. Most of the species lost are unknown. Their inherent and aesthetic value, and their potential agricultural, pharmaceutical, or silvicultural values vanish with them. Although the accelerated pace of deforestation in the humid tropics has drawn widespread attention and is of immediate concern, the degradation of natural ecosystems and habitats, and the loss of their characteristic species diversity, are occurring in nearly every part of the globe as human populations and their support systems expand. We are at a critical juncture for the conservation and study of biological diversity; such an opportunity will not occur again. The Earth's biota is experiencing its greatest episode of species loss since the end of the Cretaceous Era 65 million years ago. More importantly, it is the first mass extinction event that has been caused by a single species—one that we now hope will act, if for no other reason than its own self-interest, to stem the tide (NSB, 1989). The proximate causes of biodiversity loss are biological, but the root causes of the problem include sociological and economic processes that operate on a global scale. A thorough understanding of the phenomenon will require the investigation and elucidation of both biological and social components, and international cooperation will be necessary to develop both this scientific knowledge and successful

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Conserving Biodiversity: A Research Agenda for Development Agencies mitigation and management strategies. Unless the international community can, indeed, reverse the trend over the next few decades, the erosion of the Earth's biological legacy will continue to accelerate. Natural Versus Accelerated Rates of Biodiversity Loss The diversity of life on Earth has never been, and never will be, static. Global biodiversity has fluctuated through geologic time as evolution has added new species and extinction has taken them away. Evolution and extinction are natural processes, the responses of populations of organisms to changes in their physical and biological environment. Change is, in a very real sense, a basic fact of life (Jablonski, 1991). If change is the norm, why are we now concerned about the conservation of biodiversity? In the past, the environmental changes responsible for fluctuations in diversity occurred over relatively long periods of time. Over the past 15 million years, for example, many parts of the world have gradually become more arid, which has changed the nature of their constituent ecosystems. Even times of relatively rapid environmental change allow organisms the chance to adapt. Over the last 2 million years—a short period by geological standards—glaciers have frequently advanced and retreated, but at a rate gradual enough to allow organisms to migrate and evolve in response. Natural calamities have occasionally destroyed most or even all of one type of ecosystem and great numbers of organisms, but there were always refuges for some species and niches large or small in which evolutionary processes could continue. Even given the role that human beings have had in recent (late Pleistocene and Holocene) extinctions, these have still been isolated, rather than systematic. The environmental changes affecting biodiversity today have a different origin, order, and magnitude than those recorded in geologic annals. Today, the rate and scale of environmental changes brought about by human activities have increased to the point where a great many species may not have sufficient time or space in which to migrate or adapt. The current loss of biodiversity has several causes (McNeely et al., 1990; Soulé, 1991). The direct destruction, conversion, or degradation of ecosystems results in the loss of entire assemblages of species. Overexploitation, habitat disturbance, pollution, and the introduction of exotic species accelerate the loss of individual species within communities or ecosystems. More subtly, selective pressures arising directly and indirectly from human activities can result in the loss of genetic variability. Exploitation, habitat alteration, the presence of

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Conserving Biodiversity: A Research Agenda for Development Agencies chemical toxins, or regional climate change may eliminate some genetically distinct parts of a population yet not cause extinction of the entire species. As genetic variability is lost, however, the species as a whole becomes more vulnerable to other factors, more susceptible to problems of inbreeding, and less adaptable to environmental change. The most important single factor affecting the fate of biodiversity on Earth is the accelerated rate of habitat destruction, particularly in the tropical forests. When an area of forest is cut and the land is converted to intensified use, most of the species living in it cannot survive in the replacement system, be it an agricultural field, pasture, or plantation forest. When any habitat type is reduced to small patches, the organisms that depend on it are in greater danger of extinction as their populations are reduced in number, isolated, and subject to the highly altered impacts of sun, wind, water, soil conditions, other organisms, and human beings. These and other factors enter selectively into small patches of any habitat, severely reducing the diversity of life in that locale (Harris, 1984; Saunders et al., 1991). In the past, when human activities slowly altered limited areas of the Earth's surface, the rate of local extinctions was barely distinguishable from the natural background rate. Now we may be losing species at a rate 1,000 to 10,000 times greater than the background rate (Wilson, 1988). As Robinson (1988) notes, "We are destroying irreplaceable species on an unprecedented scale without regard for their potential economic, aesthetic, or biological significance." Even conservative estimates of species loss rates suggest that unless current trends are reversed, more than one-quarter of the Earth's species, may vanish in the next 50 years (Raven, 1988; Wilson, 1989; Reid and Miller, 1989; Ehrlich and Wilson, 1991). Unlike these currently threatened species, or those whose fate is now part of the geologic record, human beings can decide not to choose extinction. We can change our behavior and stop the acceleration of environmental degradation and species loss, thereby safeguarding species, their habitats, and our own future options for their use and enjoyment. SCIENTIFIC UNDERSTANDING OF BIODIVERSITY Our understanding of the Earth's biological diversity has significant gaps.* This lack of information hampers our ability to comprehend the *   A recent review of the state of scientific understanding has been provided by the National Science Board (1989) of the National Science Foundation in its report Loss of Biological Diversity: A Global Crisis Requiring International Solutions. This report provides the basis for the present discussion (see also Reid and Miller, 1989; Soulé and Kohm, 1989).

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Conserving Biodiversity: A Research Agenda for Development Agencies magnitude of the loss of biodiversity, prevent further losses, and formulate sustainable alternatives to resource depletion. Answers are still unavailable for seemingly simple but important questions: How many species are there? Where do they occur? What is their ecological role? What is their status—common, rare, endangered, extinct? Although schemes for classifying organisms date back at least to Aristotle, biologists are still very far from completing an inventory of the Earth's animals, plants, fungi, and microorganisms. The idea of producing encyclopedic treatments of the world's animals and plants began about 300 years ago, toward the close of the seventeenth century. In the eighteenth century, the Swedish naturalist Linnaeus, building on this encyclopedist tradition, devised the system of plant and animal taxonomy involving binomial Latin names that is still used today, in essentially the same form (Mayr, 1982). To date, some 1.4 million kinds of organisms have been assigned scientific names, but coverage is complete for only a few well-studied taxonomic groups such as vertebrates, angiosperms, and butterflies (Wilson, 1998; see table 1-1). Most groups and many major habitats such as coral reefs, the deep sea floor and thermal vents, tropical soils and forest canopies, remain poorly studied. Current estimates of the Earth's total species diversity range from 10 million to 100 million (Wilson, 1988; Ehrlich and Wilson, 1991; Erwin, 1991). Thus, as Wilson (1988) has pointed out, we do not know even to within the nearest order of magnitude the number of species on the planet. Even among those species that have been named, very few have been subject to close biological description or study (NSB, 1989). Current scientific knowledge, then, is adequate for estimating only the most general characteristics of the abundance and distribution of plants, animals, fungi, and microorganisms of the world. In the following discussions of major taxonomic groups, aquatic systems, and marine biota, emphasis is therefore placed less on numbers than on the relative abundance, ecological importance, and economic and scientific significance of organisms. Plants Most estimates suggest that there are about 250,000 species of vascular plants in the world. Approximately two-thirds of these are found in the tropics. The New World tropics are particularly rich in species. For example, at least one-sixth of the Earth's diversity of plant life—45,000 species—can be found in Latin America in Ecuador, Peru, and Colombia, which constitute an area about one-third the size of the contiguous United States. There may be twice as many species in Costa Rica, which is about the size of West Virginia, as have been named for the entire tropics of the world (Latin America, Asia, and

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Conserving Biodiversity: A Research Agenda for Development Agencies TABLE 1-1 Numbers of Described Species of Living Organisms Kingdom and Major Subdivision Common Name No. of Described Species Totals Virus     Viruses 1,000 (order of magnitude only) 1,000 Monera   Bacteria Bacteria 3,000   Myxoplasma Bacteria 60   Cyanophycota Blue-green algae 1,700 4,760 Fungi   Zygomycota Zygomycete fungi 665   Ascomycota (including 18,000 linchen fungi) Cup fungi 28,650   Basidiomycota Basidomycete fungi 16,000   Oomycota Water molds 580   Chytridiomycota Chytrids 575   Acrasiomycota Cellular slime molds 13   Myxomycota Plasmodial slime molds 500 46,983 Algae   Chlorophyta Green algae 7,000   Phaeophyta Brown algae 1,500   Rhodophyta Red algae 4,000   Chrysophyta Chrysophyte algae 12,500   Pyrrophyta Dinoflagellates 1,100   Euglenophyta Euglenoids 800 26,900 Plantae   Byrophyta Mosses, liverworts, hornworts 16,600   Psilophyta Psilopsids 9   Lycopodiophyta Lycophytes 1,275   Equisetophyta Horsetails 15   Filicophyta Ferns 10,000   Gymnosperma Gymnosperms 529   Dicotolydonae Dicots 170,000   Monocotolydonae Monocots 50,000 248,428 Protozoa     Protozoans: 30,800     Sarcomastigophorans, ciliates, and smaller groups   30,800 Animalia   Porifera Sponges 5,000   Cnidaria, Ctenophora Jellyfish, corals, comb jellies 9,000   Platyhelminthes Flatworms 12,200   Nematoda Nematodes (roundworms 12,000   Annelida Annelids (earthworms and relatives) 12,000   Molluscs Mollusks 50,000   Echinodermata Echinoderms (starfish and relatives 6,100   Arthropoda Arthropods 751,000   Insecta Insects     Other arthropods   123,161   Minor invertebrate phyla   9,300 989,761 Chordata   Tunicata Tunicates 1,250   Cephalochordata Acorn worms 23  

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Conserving Biodiversity: A Research Agenda for Development Agencies Kingdom and Major Subdivision Common Name No. of Described Species Totals Vertebrate Vertebrates     Agnatha Lampreys and other jawless fishes 63   Chrondrichthyes Sharks and other cartilaginous fishes 843   Osteichthyes Bony fishes 18,150   Amphibia Amphibians 4,184   Reptilia Reptiles 6,300   Aves Birds 9,040   Mammalia Mammals 4,000 43,853 TOTAL, all organisms     1,392,485   Source: Wilson, 1988. Africa combined). Although estimates of the total number of plant species are believed to be relatively accurate compared to other groups, more specific biological knowledge is lacking for most plants. The ability of plants, along with algae and photosynthetic bacteria, to convert radiant energy into chemical energy through photosynthesis places them at the base of all food chains (with the exception of the recently discovered sulfur-reducing chemosynthetic bacteria associated with some deep sea thermal vents). Because many species depend on specific plants for food and other habitat requirements, the destruction of plant diversity threatens much of the diversity of life in general. One-half of the total species diversity of the Earth may be found in the tropical forests and is, therefore, threatened by their destruction or degradation. If current trends continue, almost all the remaining tropical forests will be severely damaged or reduced to small patches within the next few decades, resulting in the extinction of many as yet unknown plant species (Raven, 1988). The many and varied human uses of plants—as sources of food, medicines, fibers, waxes, oils, and construction materials; as ornamentals; and as providers of a wide range of environmental services—are too numerous to catalog here. It is important to note, however, that new uses for plants are discovered regularly, and research continues to expand our understanding of their role in ecological processes at all levels. Recent interest in taxol, for example, an anti-cancer agent derived from the bark of the Pacific yew (Taxus brevifolia), highlights not only our continued reliance on plant-derived drugs, but our lack of knowledge of the biochemical properties of even the well-inventoried plants of the Temperate Zone. The developing countries, especially those of the tropics, probably harbor many poorly known or as yet undiscovered plant species with properties of potential benefit to society. About 18,000 species of the legume family, for example, have been described, and the family

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Conserving Biodiversity: A Research Agenda for Development Agencies includes many that are widely used for foods, forage, and oils. It also includes many important tropical timber trees. Most legumes form nodules on their roots that harbor bacteria of the genus Rhizobium , which are able to convert atmospheric nitrogen directly into a form in which it can be used for plant growth by both the legumes themselves and other organisms. Both the winged bean (Psophocarpus tetragonolobus), a food plant native to Papua New Guinea whose use has spread widely through the moist tropics over the past 15 years, and the "wonder tree" ipil-ipil (Leucaena leucocephala), native to Central America but carried by the Spaniards to Hawaii and the Philippines, and now hailed as a solution to problems of soil erosion and firewood shortages, are legumes (NRC, 1975, 1979). Legumes are obviously of great economic importance and have significant potential as genetic raw material for agricultural biotechnology. However, most of those that are now used in agroecosystems were discovered quite by chance. Little is being done to investigate the enormous numbers of legume species that exist in the tropics: 6,000 can be found in Latin America alone; of these, an estimated 2,000 or more are threatened with extinction as the forests of Latin America are degraded and disappear. Unless work on these species is undertaken immediately, most will never have been studied in relation to their utility, nor will they have been incorporated into botanical gardens or seed banks. Although work in plant taxonomy continues, no coordinated effort to inventory the plants of the world has been initiated, and no general data bank exists from which information about such plants can be retrieved. International networks of botanical gardens, seed banks, and other ex situ strategies for preserving plants are in place in some regions but need to be strengthened. Of special concern in this regard is the accelerated loss of genetic diversity in domesticated crops, their varieties and landraces, and their wild relatives. This diversity of germ-plasm resources has been largely responsible for the gains made in agricultural productivity in recent decades, but even as that diversity is being called upon to meet new agronomic and environmental needs, it faces growing threats (NRC, 1991b). The expansion of plant inventories, screening, the dissemination of information, and conservation efforts on a global basis—which can build on efforts at the national level—should be matters of high priority, based on our absolute dependence on plants and our ignorance of the properties of most of them. The estimated 250,000 species of plants are manageable in the sense that the status of their population can be monitored relatively easily, and they can be cultivated and reintroduced into the wild where necessary. Progress in all of these efforts, however, is hindered by a lack of financing and by a dearth of scientists trained for systematic studies in tropical countries. The insufficient number

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Conserving Biodiversity: A Research Agenda for Development Agencies diseases are usually considered in terms of their human economic and medical consequences, microbial and parasitic diseases also play a significant role in population regulation within natural communities. Human-induced changes in ecosystems and the resulting alteration in host species abundances can have unforeseen and undesirable effects on the epidemiology of those diseases. Humans have derived many benefits from scientific knowledge of microorganisms. Actinomycetes alone have been the source of 3,000 antibiotics since 1950 (Demain and Solomon, 1981). In the future, biotechnology promises to increase the use of microorganisms in solving medical, agricultural, and environmental problems. The foundations of research and development in biotechnology are the fundamental understanding and techniques of molecular biology and genetics, and the diversity of naturally occurring organisms. For biotechnology to realize its potential, more knowledge is required about the microorganisms that are the basis for new technologies. In the past, little funding has been devoted to work in microbial systematics and ecology. In developing countries, the UNESCO-organized network of Microbiological Resource Centres (MIRCENs) helps link scientists in many countries, and serves as a repository of knowledge and germ plasm for microorganisms. However, the resources available to the MIRCENs are woefully inadequate, and they are able to concentrate their efforts only on well-known organisms such as Rhizobium and Frankia. In general, little is known about the distribution or diversity of microorganisms, much less about their functional role in ecosystems. What we are learning suggests that they are even more important in supporting healthy ecological systems and biological productivity than previously believed. Improvement in our scientific understanding of microbial ecology will require increased knowledge of microbial systematics—a daunting challenge. Because research on the biology of microorganisms, especially bacteria, involves so much biochemical experimentation, it is expensive. Furthermore, money alone is not the answer. As in other areas of systematic biology, the human resource base here is thin, and institutional support is meager. Rectifying this situation will require attention to education at all levels and to training, retraining, and employment opportunities in universities, agencies, industry, and other organizations. Invertebrates Our knowledge of invertebrate species diversity, like that of microorganisms, is poor for most of the world, especially soil and marine environments, and tropical forests. No more than 10 percent of

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Conserving Biodiversity: A Research Agenda for Development Agencies invertebrate species, and probably a far lower percentage, have actually been described. For some groups such as mites and nematodes, taxonomic work has only begun. The statistics regarding invertebrates are striking. Approximately two-thirds of the 1.4 million described species are invertebrates (Wilson, 1988). Of these, the vast majority are insects. On a single tree in the Tambopata Reserve in Peru, Wilson (1987) collected 43 species of ants belonging to 26 genera. Collections of arthropods from tropical forest canopies have led scientists to suggest that sharply higher estimates of the total number of species on Earth may be warranted (Erwin, 1982, 1983, 1991; Stork, 1988). The biomass figures are equally commanding. For example, ants alone probably comprise between 5 and 15 percent of the biomass of the entire fauna of most terrestrial ecosystems. Invertebrates play pervasive, though often unseen, roles in many ecosystem functions, including pollination, decomposition, disease transmission, and regulation of other populations. For example, the interactions of soil mesofauna (e.g., nematodes, collembolans, and mites) and soil microorganisms are crucial in maintaining the plant-soil system. Nematodes both feed on and act as dispersal agents for soil bacteria. Marine invertebrates play major roles in ecosystem function in the ocean, many of which are analogous to those in terrestrial systems (but there are no pollinators). Marine protozoans, as well as crustaceans (e.g., copepods, euphausids, isopods, amphipods, and larvae of other species), link marine primary producers (phytoplankton) with higher levels of the marine food web, such as fish and marine mammals. Some invertebrates (e.g., squid and octopods) feed on or parasitize marine vertebrates. Invertebrates such as corals and some mollusks can substantially modify the physical structure of the marine environment by building reefs. Marine grazers, such as mollusks and echinoderms, can reduce the structural complexity of the marine environment by removing marine macroalgae and angiosperms. Suspension-feeding mollusks and other invertebrates can control particle concentrations in enclosed bodies of water, affecting water turbidity and the water column concentrations of particle-bound elements and compounds. Marine invertebrates also have both positive and negative impacts on humans. Mollusks, crustaceans, and echinoderms are a major source of food in some areas of the world. Some mollusks and echinoderms are used in biomedical research. Invertebrate growth on hard surfaces, such as ships, piers, and buoys, causes major damage each year and humans spend a great deal of money every year to coat marine surfaces with toxicant-fouling materials. Other species actually burrow into wood and rocks, causing structures made of these materials to fail.

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Conserving Biodiversity: A Research Agenda for Development Agencies Marine invertebrate parasites and disease organisms are not as common as their freshwater and terrestrial counterparts. The activities of invertebrates can have major economic impacts on humans. Many crops, for example, depend on insect pollinators, yet they can incur significant damage from other insects. Many of the major human diseases—malaria, schistosomiasis, bubonic plague, encephalitis—are caused by or transmitted through invertebrates. For example, the recent spread of Lyme disease in the United States has been linked to ticks that carry the spirochete agent while spending different parts of their life cycles on white-tailed deer and mice. Abundant as they are, terrestrial invertebrates are also more prone to extinction than most other groups of organisms. Many species are highly specialized with respect to food, habitat, or other environmental requirements and thus are subject to extinction as a result of even relatively small-scale environmental degradation. This is especially true of tropical forest insects, whose ranges are often quite restricted. The alterations of habitat, on all scales, that are taking place in tropical regions thus result in far greater incidence of invertebrate species loss than would alterations on a similar scale in temperate regions. Studies of invertebrates do not reflect either their numbers or their importance in ecosystems, which represents a primary constraint of biodiversity research as a whole. Invertebrate systematics, especially in the tropical ecosystems of developing countries, is a neglected area in a neglected branch of basic biology. Important taxonomic groups of great diversity are often the responsibility of a handful of resident scientists in tropical countries, while very limited help is available from the large museums of temperate regions. Moreover, many of the present experts are senior scientists whose administrative responsibilities leave them little time for basic taxonomic work (NAS, 1980). Until scientists from temperate and tropical zones alike are encouraged and rewarded for taking up these fundamental taxonomic studies, the lack of trained systematists will be an important limiting factor in the advancement of knowledge on biological diversity. Vertebrates As a group, vertebrates have been more thoroughly studied than most other organisms. Approximately 41,000 species have been described, but many have yet to be discovered. Almost half of the known vertebrates are fish, and most of those that remain undescribed are likely to be fish, primarily because of their relatively inaccessible habitats. For example, it has been estimated that as many as 40 percent of the freshwater fish of South America have not yet been classified scientifically (Böhlke et al., 1978), and the

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Conserving Biodiversity: A Research Agenda for Development Agencies fish of tropical Asia are also poorly known. Data on life-history patterns, food webs, and the behavior of fish are for the most part lacking. Major stocks of many commercial species may be depleted to such an extent in the near future that it will be impossible to study the variety of their adaptations and the conditions under which they evolved. This is especially true with respect to migrating fish that depend on unimpeded access to upper regions of rivers, which are often favored sites for dams. Information of this type is of fundamental ecological and economic importance. Fish also represent a critical human food resource that is insufficiently understood to be used on a fully sustainable basis. In the same sense that tropical rain forests might contain many species whose products could be of great use, fish communities may include members whose nutritional modes, defense mechanisms, behavior, or growth characteristics could be applied in the production of proteins, medicines, or fertilizers, and in the management of aquatic habitats. In comparison to other taxonomic groups, there are few undescribed species of reptiles, birds, and mammals. Nonetheless, new species continue to be discovered fairly regularly. Even among primates—the most widely and carefully studied group of organisms—new discoveries are still being made. The black-faced lion tamarin, Leontopithecus caissara, a previously unknown primate, was discovered in 1990 by two Brazilian biologists on an island close to São Paulo (Lorini and Persson, 1990). Despite our relatively complete knowledge of the species diversity within these groups, we know nothing more about the vast majority of them except that they exist. Vertebrates—especially those that have been domesticated—are the species of greatest economic and aesthetic importance to human beings. Because much basic zoological research has focused on domesticated vertebrate species and because much of our previous conservation research has focused on wild vertebrate species, these are important models as biodiversity research expands. Moreover, because the highest trophic levels within ecosystems are generally occupied by reptiles, birds, and mammals, efforts to preserve diversity among these groups will have beneficial impacts on other organisms that share—and constitute—their habitat. Tropical Aquatic Systems Tropical rivers, lakes, and wetlands are among the richest, most important, yet least studied, habitats in the developing world. The 1980 National Academy of Sciences report Research Priorities in Tropical Biology noted the critical scientific and economic importance of these systems, and recommended that they be studied much more intensively

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Conserving Biodiversity: A Research Agenda for Development Agencies and monitored for long-term changes (NAS, 1980). The need for scientific study of these systems, particularly of their biological diversity, has increased in the interim. Watershed development projects of all kinds inevitably alter river systems and their biota, usually before scientific investigations of unmodified watersheds and basins take place. Research must focus on river systems prior to development if any accurate characterization is to be made of their biological diversity, ecosystem functions, and hydrological dynamics. This need, it should be noted, pertains to rivers in both tropical and nontropical developing countries. In the tropics, it includes both the great rivers—the Amazon, Orinoco, Parana, Zaire, Niger, Nile, Mekong—and the many minor rivers and tributaries. The needs and opportunities for research in this area are great. The composition, abundance, and functioning of the plankton of large rivers in their natural state are essentially unstudied, and although the opportunity has largely been lost in temperate regions, it is still possible in the tropics (NAS, 1980). The invertebrates of tropical rivers, immense in their variety, are largely unstudied because of the shortage of trained taxonomic experts. Knowledge of the fish and other vertebrates of tropical rivers is somewhat more advanced, but as more systems are altered, the opportunity for comprehensive studies of riverine community structures, trophic interactions, and vertebrate population dynamics becomes increasingly scarce. Lakes are less common in the tropics than in the temperate zones, primarily because glaciation was a less significant factor in the geological history of the tropics. Nonetheless, the special physical features, high productivity, economic importance, and vulnerability of tropical lakes make the study of their biological diversity particularly important. A number of tropical lakes, large and small, support high levels of fish endemism and merit study not only because of their inherent importance for science, but also because of their susceptibility to the effects of exotic fish introductions. The unique circumstances under which the biota of tropical lakes has evolved and the likelihood of alteration due to development pressures make these lakes important sites for expanded scientific attention. Especially important are Lake Malawi in Africa's Great Rift Valley, Lake Titicaca and smaller lakes of the high Andes, Lake Maracaibo in Venezuela, Lake Toba in Sumatra, and many smaller lakes of insular Southeast Asia (NAS, 1980). Tropical wetlands, of many varieties, are among the most productive freshwater systems in the world. They are also highly vulnerable to destruction by drainage, conversion to intensive rice production, and the alteration of associated river systems (NAS, 1980). Many of the most important—the Sudd in the Sudan, the Okavango of Botswana, the Pantanal of Brazil, the wetlands of the Sepik and Fly Rivers of Papua

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Conserving Biodiversity: A Research Agenda for Development Agencies New Guinea—exhibit distinctive species compositions, evolutionary adaptations, energy-flow characteristics, and population dynamics as a result of seasonal fluctuations in water levels and unique chemical factors. Studies of the biological diversity of these systems are critical in understanding how they function, and how human alteration and use of tropical wetlands may affect their diversity and productivity. Marine Biota Until recently, interest in biological diversity and its conservation focused primarily on terrestrial and freshwater environments, and thus neglected the most extensive habitat on Earth (Ray, 1988). The very vastness of the marine environment (oceans cover 70 percent of the Earth's surface), the variety of ecosystems it contains, and the difficulties involved in exploring and studying the life of the sea have hampered efforts to treat marine biodiversity more comprehensively. Marine organisms have long been used in cell biology and other areas of basic biological research, and certain communities—in particular, coastal wetlands, mangrove forests, and coral reefs (the species richness of which is often compared to that of tropical rain forests)—have been studied in detail. In general, however, relatively little is known about the diversity, abundance, and distribution of marine organisms or the structure and function of marine ecosystems. Marine systems are distinguished by their high degree of diversity at all taxonomic levels. Current estimates of the total number of species on the planet assume that approximately 94 percent of the species are terrestrial. Recent research, however, suggests that previously unexplored marine habitats, especially the deep sea and the ocean floor, may harbor millions of additional species, thus rivaling the species richness even of the tropical forests. Moreover, if we measure diversity in the broader taxonomic categories—phyla, classes, divisions—then the greatest variety of life on Earth is unquestionably contained within the seas (Thorne-Miller and Cantena, 1991). It is not uncommon to find representatives of a dozen or more basic classes or divisions in the same small space—a breadth of diversity that has no match on land. Fish, marine mammals, mollusks, and corals are the best-known groups of marine organisms. However, major groups of organisms and new habitats are still being discovered. The phylum Loricifera was first described in 1983 (Kristensen, 1983), and an entirely new habitat was revealed with the discovery of ocean vent systems. The bottom of the ocean is still largely unexplored; assaying and understanding its biological diversity will require resources equivalent to those committed

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Conserving Biodiversity: A Research Agenda for Development Agencies for exploring the Moon. Because such research depends on costly and specialized equipment, funding for ships and associated sampling tools is a limiting factor (NSB, 1989). The importance of marine biodiversity is almost as vast as the oceans themselves. Much of the Earth's human population depends on the oceans, especially marine coastal systems, for food. In the developing nations, more than half of the population obtains at least 40 percent of its animal protein from fish (WRI, 1986). Some 9,000 species of fish are currently exploited for food, although only 22 are harvested in significant quantities on a global scale (WRI, 1987). Approximately 80 percent of the marine species of commercial importance occur within 200 miles of a coast. Marine flora and fauna are also extensively used in the production of antibiotics and other pharmaceuticals, food additives and processing agents, and a variety of manufactured goods. Above and beyond these commodity values, marine organisms are critical determinants of the structure and function of the global ecosystem. Marine phytoplankton, for example, are the foundation of marine food chains and play an important role in atmospheric dynamics. The interactions among marine biota, the Earth's geochemical cycles, and global climate change are just coming to light, and even our most advanced computer models have been able to offer only the roughest approximations of the feedback mechanisms involved in the maintenance of biospheric conditions. The study of marine biodiversity is thus critical to understanding environmental dynamics on the global, as well as on local and regional, scales. Interest in the conservation of marine biodiversity is a relatively recent phenomenon. The immensity that makes oceans such a challenge to study has also made it possible to believe that anthropogenic disturbances would remain limited in their environmental impact. Compared to terrestrial environments, oceans provide relatively stable, extensive, open, well-buffered habitats for the organisms that inhabit them. Nonetheless, the threats to marine diversity are much the same as on land: habitat destruction (especially in coastal, estuarine, wetland, and coral reef systems); pollution (including suspended sediments, nutrients, and toxics); overexploitation of harvestable species (including fish, shellfish, turtles, and mammalian species); and the specter of global climate change with all its attendant marine impacts (Soulé, 1991; Thorne-Miller and Cantena, 1991). Although the biota of oceans has been protected from many of these impacts by the extent of the medium itself, environmental stresses can be expected to place the same pressures on marine systems that they are placing on terrestrial systems. So little is known about marine biota that rates of extinction are difficult to estimate. Ray (1988), however, suggests that the degradation of coastal zones is occurring as rapidly

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Conserving Biodiversity: A Research Agenda for Development Agencies as tropical forest destruction, and recent findings indicate that coral reefs may be among those communities most seriously imperiled by human activities (Salvat, 1987; Guzman, 1991). As in terrestrial systems, inventories and ecological studies are needed for all oceans, with special emphasis on those habitats most immediately threatened. This brief review does not reflect the full status of scientific knowledge with regard to specific taxa, geographic areas, ecosystems, or habitats, and only touches on genetic-level diversity and the vitally important relationship between ecosystem dynamics and diversity. As we seek the means to slow or reverse the losses, we will have to secure increased support for established scientific efforts in systematics and resource management, and for relatively new scientific endeavors in such integrative, applied fields as sustainable agriculture, conservation biology, and restoration ecology. We face an unprecedented situation that demands new combinations of the basic and applied sciences, the expertise of specialists and the vision of generalists, conceptual clarity as well as concrete experience. The science of biological diversity and its conservation demands not only more knowledge but new kinds of knowledge, and new ways of synthesizing what we know. IMPLICATIONS FOR DEVELOPMENT AGENCIES Biological diversity reaches its highest levels, and faces its greatest risks, in the developing nations of the world, primarily because of intensive resource exploitation and the extensive alteration of habitats. This is due in part, however, to international markets, development policies, and lending practices that transfer financial resources from developing countries to industrial countries and undermine the capacity of developing countries to sustainably manage their resources. Rapid population growth, extreme and persistent poverty, social inequity, institutional breakdown, and perverse policy incentives have brought unstable economic conditions to many developing nations. In response, many of these countries have had to adopt short-term development agendas and exploitative resource management practices aimed at increasing foreign exchange earnings from their undiversified economics. Trade in elephant ivory (mostly illegal) and tropical timber (legal) provides obvious examples that have important consequences for the maintenance of biodiversity, but other less publicized practices—overgrazing of ranges, expansion of cash crop agriculture, intensified shifting cultivation—also lead directly to the demise of species and habitats. As a result of these interrelated social, economic, and environmental trends, many developing countries have begun to question the sus-

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Conserving Biodiversity: A Research Agenda for Development Agencies tainability of current resource management practices and look for more promising alternatives. The policies and funding practices of international development agencies, if directed toward wise, long-term commitments of assistance, can aid in this by affording developing countries greater economic stability and hence greater national capacity to preserve biological diversity. In the past, development agencies have funded infrastructural development activities, agricultural expansion programs, dams, and other large-scale projects that have contributed directly to the loss of biological diversity, while doing little to ease the indirect causes of resource decline (NSB, 1989). A new vision is necessary at all levels of the development community—one that recognizes the inextricably connected fate of human communities and the biotic community, of development and conservation. Biological diversity is, in the most literal sense, the basis of sustainable development and resource management. By conserving biodiversity, we retain not only plants and animals, soils and waters, but the foundations of sustainable societies and the availability of options for future generations. Fuelwood gathering, to cite just one example, is a significant contributing factor behind the rising rates of deforestation in many parts of the tropics. A billion and half people in developing countries depend on firewood as their major fuel source. In many areas, expanding demand and declining local supplies have led to excessive harvest rates, and acute fuelwood shortages, and subsequent decline in soil and water resources. Developing renewable, cost-effective alternative energy sources, sustainable agroforestry systems, and more productive sources of firewood, charcoal, and timber will require greater attention to potentially useful species and genetic resources (NRC, 1991a). Biodiversity, in short, must come to be seen as an inherently important aspect of every nation's heritage and as a productive, sustainable resource upon which we all depend for our present and future welfare. The conservation of biological diversity is not merely an obscure, hitherto neglected area of endeavor whose importance has only now been discovered; rather, it is a fundamental concern that has been absent in short-term development planning, at the risk of long-term social and economic well-being. Responding to Research Needs In both the developing and the developed nations, immediate action needs to be taken to protect biodiversity. At the same time, there is a continuing need for research on biodiversity that improves our knowledge base and our management capacities, and leads to the development of new ways for people to live with, and not at the expense of, their biological resources.

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Conserving Biodiversity: A Research Agenda for Development Agencies It is unlikely that poor countries will be able to support major biodiversity research enterprises, however important, in the near future. If global environmental and scientific objectives are to be served, more effective means for north-south transfers of funding must be found, and more productive mechanisms for scientific collaboration must be invented (NSB, 1989). The international development agencies are essential in this regard. Other organizations are unlikely or unable to provide the necessary funds. In the long run, this assistance will allow developing nations to move toward greater independence by strengthening in-country research institutions. As their research capacity increases, so too will their ability to chart their own course of sustainable development. As they seek to meet these growing research needs, development agencies will themselves have to undertake institutional changes. Research on biological diversity is necessarily broad based and multidisciplinary, and the administration of research within the agencies must reflect this. Overlapping areas of biology, including ecology, sustainable agriculture, and conservation biology, are critically important in addressing the needs of developing countries and must be given greater support. More support must also be given to research that integrates economics, the social sciences, and biodiversity conservation. Above all, research must be carried out largely by people in and of the countries involved. Long-term institutional commitment is necessary. Support for these changes must be incorporated wherever possible into the human resource development programs of technical assistance agencies. All personnel should be given training in biodiversity science and policy. More personnel with the requisite background knowledge must be brought into the agencies on a permanent basis and given adequate specific training, as well as opportunities to remain up to date on research in their fields. Although development and science agencies can play a leading role in promoting these efforts, their work must involve agencies, institutions, and organizations that have not traditionally taken part in conservation activities. Finally, development agencies must have a ''built-in'' capacity to review outcomes, monitor practices, and recommend adjustments in policies that affect the status of biological diversity. Several development agency research programs have begun to reflect these needs. The U.S. Agency for International Development, for example, provides funds for innovative research on biodiversity under its Program of Scientific and Technical Cooperation (PSTC) and its Sustainable Agriculture and Natural Resource Management (SAN-REM) Collaborative Research Support Program. Support for this kind of research should be expanded and strengthened. Agencies will need to find creative ways to sustain funding for these endeavors over many

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Conserving Biodiversity: A Research Agenda for Development Agencies years, even indefinitely. National biological inventories, for example, could well be funded by pooling the resources of all international assistance agencies functioning within a given country. The research agenda outlined in the remainder of this report is intended to assist development agencies in their efforts to respond to these research needs. Research cannot, in and of itself, conserve biodiversity in developing nations any more than it can in the developed nations. What research can do, however, is provide the people and the leaders of these nations with information that may help them to improve their lives, while securing the biological legacy on which their livelihood depends.