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BioDiversity PART 3 DIVERSITY AT RISK: TROPICAL FORESTS
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BioDiversity An example of slash-and-burn agriculture, one of the major mechanisms used to clear forests. Photo courtesy of the Missouri Botanical Garden.
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BioDiversity CHAPTER 12 OUR DIMINISHING TROPICAL FORESTS PETER H.RAVEN Director, Missouri Botanical Garden, St. Louis, Missouri In any discussion of biological diversity, tropical forests must occupy center stage. Broadly defined, these forests are home to at least two-thirds of the world’s organisms, a number that amounts to no fewer than 3 million species, and could be 10 or more times greater than that amount. Striking, however, is the fact that only about 500,000 species from the tropical and subtropical regions of the world have been given names and been cataloged in the scientific literature. This means, very simply, that where one might expect to identify the great majority of any collection of insects or other arthropods made within the boundaries of Europe or temperate North America, only a very few of those in any reasonably diverse sample of tropical organisms—at least among relatively small and inconspicuous groups—could be located in the world’s collections, or are mentioned in the world’s literature. Even among those very few, only a tiny fraction would be known from more than one or several specimens, a few short lines of technical description, and a locality. In short, identifying them would not provide much help concerning their ecology, their evolutionary relationships, their behavior—or any of the components that might have been involved in their history, or that might contribute to their chances of survival. Such matters must be considered seriously as we learn more about the diversity of organisms itself. Regardless of whether there are 2.5 million more tropical organisms to be named or 25 million, the task facing us is enormous. All the activities of all those concerned with cataloging organisms over the past centuries in all types of ecosystems throughout the world have resulted in the naming of only about 1.5 million of them, and a task at least twice, and perhaps many times, that large confronts us now. All the scientific and societal gains that depend on an increased knowledge of these
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BioDiversity organisms (we must know that they exist before we can understand or use them) depend on the degree to which that task can be completed. Since all of human society depends directly or indirectly on our ability to manage plants, animals, and microorganisms effectively, the task is one of enormous importance. In light of the rapid destruction of tropical forests, it is an especially urgent matter to catalog the organisms in those regions and to establish well-considered priorities for this undertaking. It is clear that most tropical forests will have been destroyed or severely damaged within the next 25 years, because of the size of the human population in the tropics and subtropics, already constituting a majority of the world’s people and growing explosively; the extensive poverty there, which afflicts well over a third of the people; and our collective ignorance of effective ways to manage tropical ecosystems so that they will be productive on a sustainable basis. By 2010, the only large blocks of undamaged forest remaining will be those in the western and northern Brazilian Amazon, the interior of the Guyanas, and the central Zaire (Congo) basin in Africa. All the forests in other parts of the tropics and subtropics (those in Mexico, Central America, the West Indies, Andean South America, the eastern and southern portions of the Amazon), all the forests of Africa outside the central Zaire basin, and all the forests of tropical and subtropical Asia will have been devastated by that time. There will of course be exceptional preserved areas within these regions, their sizes depending on the effectiveness of local conservation programs and on the nature of the soils underlying particular pockets of vegetation. Some areas will simply be too steep to cultivate, others too rocky, and still others too wet. In these pockets of vegetation, populations of organisms will survive; however, they will be reduced to relatively few individuals in most cases, subjected to the effects of light and heat penetrating from the edges of the fragmented patches of forest in which they are surviving, and assaulted by human activities related to their greater accessibility. For example, the hunting of primates and other animals (discussed by Mittermeier in Chapter 16) is often greatly intensified when the surviving patches of vegetation are small. Because of the nature of small populations—they are unlikely to persist long owing to chance alone—and the increasing strains on these pockets of vegetation, many of the species that initially survive locally are likely to become extinct within a very few years. The question arises as to whether large, important preserves such as Manu Park in Peru or the Tai Forest in the Ivory Coast can survive until the projected stabilization of the human population in the second half of the next century. As in other tropical and subtropical countries, human pressures in Peru and the Ivory Coast are incredible, and resources tend to be consumed in meeting the needs of rapidly growing populations with high proportions of poor, often malnourished people. Over the next few years, the confrontation between human needs and forest preservation, already evident in many areas, will become more acute. The protection of such major reserves is conceivable, however, if there is a genuine willingness to share resources on a global level—to provide major support from industrialized countries not merely for the protection of parks and reserves but for the creation of conditions in which all people can live with a measure of human
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BioDiversity dignity. The decisive factors will be social, political, and economic; they will not be limited simply to a willingness to conserve. Putting these relationships in another context, and assuming that two-thirds of the world’s 4 to 5 million species are located in the tropics and subtropics, nearly half the world’s species of plants, animals, and microorganisms will be destroyed or severely threatened over the next quarter century—well within the expected life span of most people living today. If half these organisms become extinct during the next several decades—surely a conservative estimate—the world will experience a major episode of extinction. This episode could amount to the loss of perhaps 10% of the world’s species by the end of the century and to more than a 25% loss within the next couple of decades. These estimates are compatible with the predictions of extinction rates for primates and other relatively well-studied groups of organisms and with the closely coupled nature of the biological relationships involved. To find a comparable rate of extinction, one needs to go back more than 65 million years to the end of the Cretaceous period, when the dinosaurs disappeared along with a major loss of other life on Earth. In fact, the rate of extinction that will be characteristic of most of the remaining lifetimes of those now living is estimated to be at least 1,000 times the normal rate. Since there are now many more species than there were 65 million years ago, the absolute loss in number of species will be much greater. For a more concrete example, consider the flowering plants. We obtain 85% of our food directly or indirectly from just 20 kinds of plants, and about two-thirds from just three: maize (corn), wheat, and rice. The 20 species were brought into cultivation thousands of years ago, largely because they were easy to grow; they were not selected because of their ability to contribute to the needs of a modern industrial civilization. Despite that, they are precious. Widespread starvation in the tropics and subtropics, however, reminds us that temperate-zone agriculture is not suitable everywhere, and suggests that an enhanced ability to cultivate some of the other 250,000 species of flowering plants might offer rewards by providing food crops that can be cultivated successfully in areas where the cultivation of present food plants is now difficult or impossible. In evaluating our future opportunities to use the lesser known plants, however, consider the significance of the extinction projections reviewed above. Some 25,000 species of plants—about 5 species a day—are expected to disappear between now and the end of the century, and then perhaps 10 species a day will become extinct over the following couple of decades. Clearly, many of the 50,000 species of plants expected to vanish forever during our lives hold exceptional promise for producing food, fodder, wood, medicine—all the factors that increase the quality and stability of human existence on Earth. Given our record numbers, and the extreme pressure with which we are assaulting the global ecosystem, it seems absolutely mandatory that we redouble our efforts to survey, classify, preserve, and understand these plants, as well as members of other groups of organisms, while they still exist. The consequences of the destruction of tropical and subtropical forests are grave; basically, our collective actions are denying to our children and grandchildren the ability to play the game of survival with the tools that we have at our disposal
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BioDiversity today. In effect, we are, by our passivity, making the effort to survive through the creation and maintenance of stable, productive ecosystems more difficult for them than it is for us. The kind of restoration ecology described so eloquently by Janzen for the dry forest in Chapter 14 will undoubtedly come to be practiced widely as the human population stabilizes and our relationships with the global ecosystem become more realistic. The preservation of individual species of plants, animals, and microorganisms now offers the best chance of achieving the most complete success in this complex area during the twenty-first century. Analogous is the need to preserve genes for future use in the developing field of genetic engineering. It will be decades or centuries before it is possible to synthesize genes that can confer desirable traits on recipient organisms in any but the most simplistic ways; yet living organisms contain an enormous library of such genes, already tested by nature and available for use until the organisms themselves become extinct. Through our endless preoccupation with immediate, seemingly pressing domestic problems, we are seriously damaging our prospects for the very near future by losing scientific, societally relevant, and aesthetic possibilities beyond imagining. Nonetheless, as we confront this grim spectacle, we must remember that the opportunities for studying and preserving biological diversity are greater today than they will ever be in the future. Of critical importance will be our ability to abandon our passivity and face the situation as it is, devoting increased resources to the exploration of diversity and using the information that we gain for our common benefit. In this effort, the importance of the kinds of studies described in this section is evident; they provide models of the variety of activities that should be intensified and multiplied while the opportunities are as great as those we enjoy now.
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BioDiversity CHAPTER 13 THE TROPICAL FOREST CANOPY The Heart of Biotic Diversity TERRY L.ERWIN Curator, Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. A few years ago in a short paper in the Coleopterists Bulletin, I hypothesized that instead of the current estimate of 1.5 million species on Earth, there were 30 million species of insects alone (Erwin, 1982). This hypothesis was based on collections of beetles from tropical forest canopy samples in Panama (Erwin and Scott, 1980), rather than on the catalog counts of taxonomic names used in all the earlier estimates. I used simple arithmetic based on actual numbers of beetle species in my samples, estimated numbers of tropical forest tree species given me by the leading botanists, and a conservative estimate of the host specificity of tropical forest canopy insects. Host specificity in this sense means that a species in some way is tied to the host tree species and cannot exist without it. This reestimation of the magnitude of life on Earth got a lot more coverage than I anticipated and began the usual controversy of right or wrong. Those engaged in the controversy, most of whom never read this obscure paper in the Coleopterists Bulletin, in a way actually missed the point of the paper. Consequently, I now want to take the opportunity to clarify the situation. Science, at least in natural history, proceeds from casual observations, usually in the field or on museum specimens, to the erecting of hypotheses and finally to the testing of those hypotheses. Repeated failure to prove a hypothesis false lends support to the possibility that it may be true. For the 30 million species of insects hypothesis, which was based on a brand new set of observations never before available to scientists, I suggested that testing must begin by refining of our knowledge about host specificity of insects in tropical forests. In a subsequent paper, analyzing data from the canopies of four different forests
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BioDiversity in the central Amazon around Manaus, Brazil, I showed that 83% of the beetle species in the samples were found in only the samples of one of the types of forest, 14% of the species were shared between two, and only 1% of the species of beetles was found in all four forest types (Erwin, 1983a). This added fuel to the “numbers” controversy, because of the numerous types of forest known to exist in the Amazon Basin alone and the fact that the analysis was based on more than 1,000 species of beetles, a fairly substantial data base. At this point, I turned my attention to the now well-refined sampling techniques of insecticidal fogging of forest canopies at the Tambopata Reserved Zone in the southeast corner of Amazonian Peru. I developed these techniques for the purpose of testing the main hypothesis regarding biological diversity in tropical forests and the subhypothesis that host specificity is a main feature of the lifestyle of tropical canopy insects. The following paragraphs provide some glimpses of the Tambopata Canopy Project, some preliminary observations on the fauna itself, and what I believe to be the status of the 30 million species hypothesis. With a data base of a million specimens (we’ll get to the number of species later), it will take a long time to complete the data analysis from just 1 year of collecting. THE PROBLEM It has been predicted that in 25 to 30 years, much of the humid tropical forest could be gone or severely converted (see Raven, this volume, Chapter 12). Between 25 and 40% has already been lost to misguided human exploitation. The best estimate is that an area the size of Honduras is being lost or converted each year, and by the year 2000 some popular accounts have predicted that a million species will become extinct. Although I regard such guesses as a bit low, a point discussed later in this chapter, they mean that in our generation we, the only species on Earth with the mental capacity to reason, will see the virtual disappearance of contiguous tropical forests and probably the extermination of more than 20% of the diversity of life on Earth, and we humans will have caused it. THE HISTORY The Amazon basin (Figure 13–1) has the richest biota on Earth. There are several factors involved, not the least of which is the sheer size of the basin. We must start the historical analysis with the Amazon basin as it was on the western portion of the megacontinent Gonwanaland some 100 million years ago. The biota of today is a result of many events that occurred after two supercontinents, South America and Africa, rifted, and South America drifted in a westerly direction. As this occurred, the uplift of the Andes began. This wonderful mountain chain, extending from Venezuela down into Chile, became a dike that reversed the western flow of all the rivers of Gonwana, turning them around and beginning their flow to the east. In the last 40 million years, this event has caused a mosaic of habitats, the fine-grained resolution of which we have no comprehension at this time. As I am discovering in some of my work in Peru, the fine-grainness of habitats is far, far greater than what the botanical classifications have led us to believe. We need
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BioDiversity from the botanists a better picture of tree species distribution and habitats, and of the small communities made up by these tree species microdistributions. During this 40 million years of Andean orogeny, there were three uplifts of crystalline rock across the Amazon, represented by the red arches in Figure 13–1. The two gray areas in the north and south are bedrock, the Guyana and Brazilian Shields. From this perspective, we now see the development of this mosaic of habitats, defined by the meandering river systems of the Amazon basin itself. The study of these rivers and the areas between them offers an interpretation of the events of the past (Erwin and Adis, 1982). A mosaic component that extends throughout the Amazon basin is the oxbow lake, a lake formed when a loop of a river becomes isolated from the river as a result of sedimentation. The formation of an oxbow lake is the first stage in succession that culminates in forest. This small “island” of aquatic life will soon become an island of grassy life, which will then become an island of palm tree life and so on until it returns to climax inundation or upland forest of some type. During succession, it may be crosscut by another twist of the river or another small river, which will then subdivide it into four successional stages each with a different time differential. This kind of successional evolution on a massive 6-million-square-kilometer area is but one of the features that has provided the evolutionary pathway for Amazonia’s fantastic diversity. What we see today from the air is a forest canopy that extends more or less unbroken across those 6-million-square kilometers, except for the rivers, the hy- FIGURE 13–1 The South American land mass. The Guyana and Brazilian Shields are shown in gray; the hatched areas represent the three arches of crystalline rock.
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BioDiversity droelectric projects, the Rondonia project, and various other development projects that are starting to break up that vast expanse of forest. From the air, one can detect even finer and finer mosaics. It is very easy to pick out the trees in blossom, the trees with tough dark-green leaves, trees that lost their leaves during the dry season and are now getting a new flush of very light pale leaves (the ones the insects like to eat the most), and vines that reach up into the canopy to spread their leaves over the tree leaves or intermingle them with the leaves of the canopy trees. All 150 or more species of canopy trees or vines per hectare contribute to the mosaic. There is an intermingling of leaves between two species of trees, between the vines and the trees, and between one tree overshadowing the other, resulting in the creation of microenvironments for the little creatures that are so important in providing the richness of the world’s biotic diversity. Depending on forest type, the tops of the trees range from 15 meters to as high as 55 meters. Tambopata was chosen for my preliminary studies because logistically it is very difficult to get equipment and people into a virgin rain forest, keep them there for long periods, and get the material back to the museum to study it under the microscope. The average length of the beetles in the canopy is about 2 to 3 millimeters, so one needs pretty good facilities to make detailed studies. Tambopata served the logistic purposes as well as another purpose—approximately 11 different types of forests are found within walking distance. That seemed like too much to handle during 1 year, so only five were selected for intense collecting. In each of these five forests, we selected three 12-meter-square plots (Erwin, 1983b). All 15 plots were sampled in the early rainy, late rainy, early dry, and late dry seasons. The data collected included tree canopy sizes, species of trees, and exact location of the collecting trays. All this information has been computerized and allows museum specimens to be traced back to the actual square meter of rain forest where they were collected. This gives us the opportunity to return in subsequent years and resample in order to see what the canopy, or what the forest in general, is doing over long periods. Long-term cycles have been largely overlooked, except by a few researchers for only a few species. My research team is now beginning to computerize the canopy in three dimensions so that we can describe exactly where these insect species reside in the canopy. Beyond this data set, we also have the branching patterns, the leaf structure, and other details of microhabitats. It has taken a long time to develop our data collections, because we have paid attention to the finest details. I am trying to look at the canopy habitat through the eyes of these 2- to 3-millimeter-long beetles. To date, we have analyzed about 3,000 species of beetles from only five plots. When we complete our analysis, we will have a large data set. A comparison of the tree composition of the different kinds of forest has shown that the forest in Manaus and two of our upland terra firma forests contain entirely different tree families. There are more big trees in the Peruvian sites than in the Manaus sites. Perhaps that accounts in part for the larger size of the insects in the canopy in Peru than in Manaus. Only 2.6% of the species are shared between Manaus and Tambopata (Figure 13–2). This seems reasonable, because the two sites are 1,500 kilometers apart.
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BioDiversity FIGURE 13–2 Pie diagrams of shared beetle species among forests in Peru and Brazil in percent of fauna. But we found that of the 1,080 species analyzed, there was only a 1% overlap of species in all four forest types in Manaus (Erwin, 1983a). Data collected during three seasons for two forest plots in the same type of forest 50 meters apart in Tambopata indicate that only 8.7% species are shared. When we add the fourth season data (which will come in shortly), we predict that the percentage of shared species will drop. Figure 13–3 is a cumulation species curve, which shows the increase in the number of species as we increase the samples. After this figure was made, some more samples were analyzed and the curve became much steeper. These data are just from Plot 1 in Upland Forest Type 1 (Erwin, 1985). The 3,000 species already analyzed amount to more than all the samples from Brazil. A canopy beetle is shown in Figure 13–4. In fully describing the distribution of these insects in time and space in the tropics, we should think in terms of more than 30 million, or perhaps 50 million or more, species of insects on Earth. A large number of species are tied only to certain forest types that are found on very small patches of soil deposited differentially through time by the vast and meandering Amazon River system. The extermination of 50% or more of the fauna and flora would mean that our generation will participate in an extinction process involving perhaps 20 to 30 million species. We are not talking about a few endangered species listed in the Red Data books, or the few forbish louseworts and snail darters that garner so much media attention. No matter what the number we are talking about, whether 1 million or 20 million, it is massive destruction of the biological richness of Earth.
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BioDiversity Frechione, J., D.A.Posey, and L.Francelino da Silva. 1985. The Perception of Ecological Zones and Natural Resources in the Brazilian Amazon: An Ethnoecology of Lake Coari. Paper presented at the annual meeting of the American Anthropological Association, Washington, D.C. Goodland, R.J.A. 1980. Environmental Ranking of Amazonian Development. Pp. 1–20 in F. Barbira-Scazzocchio, ed. Land, People and Planning in Contemporary Amazonia. Centre of Latin American Studies, Occasional Publication No. 3. Cambridge University, Cambridge. Gross, D.R. 1975. Protein capture and cultural development in the Amazon Basin. Am. Anthropol. 77(3):526–549. Harner, M.J. 1972. The Jivaro: People of the Sacred Waterfalls. Doubleday/Natural History Press, Garden City, N.Y. 233 pp. Hickerson, H. 1970. The Chippewa and Their Neighbors: A Study in Ethnohistory. Holt, Rinehart and Winston, New York. 133 pp. Nimuendaju, C. 1974. Farming among the Eastern Timbira. Pp. 111–119 in P.J.Lyons, ed. Native South Americans. Little, Brown, Boston. Posey, D.A. 1983. Indigenous knowledge and development: An ideological bridge to the future. Cienc. Cult. 35(7):877–894. Posey, D.A. 1985. Indigenous management of tropical forest ecosystems: The case of the Kayapo Indians of the Brazilian Amazon. Agroforestry Sys. 3:139–158. Posey, D.A., J.Frechione, J.Eddins, and L.F.da Silva. 1984. Ethnoecology as applied anthropology in Amazonian development. Hum. Org. 43(2):95–107. Ramos, A.R. 1980. Development, integration and the ethnic integrity of Brazilian Indians. Pp. 222–229 in F.Barbira-Scazzocchio, ed. Land, People and Planning in Contemporary Amazonia. Centre of Latin American Studies, Occasional Publication No. 3. Cambridge University, Cambridge. Taylor, K.I. 1974. Sanuma Fauna, Prohibitions and Classifications. Monograph No. 18. Fundacion La Salle de Ciencias Naturales, Instituto Caribe de Antropologia y Sociologia, Caracas, Venezuela. 138 pp. Taylor, K.I. 1983. Las necesidades de tierra de los Yanomami. (Abstract in English) America Indigena XLIII(3):629–654.
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BioDiversity CHAPTER 16 PRIMATE DIVERSITY AND THE TROPICAL FOREST Case Studies from Brazil and Madagascar and the Importance of the Megadiversity Countries RUSSELL A.MITTERMEIER Vice-President for Science, World Wildlife Fund/The Conservation Foundation, Washington, D.C. Much of the early interest in wildlife conservation grew out of a desire to save some of the world’s most spectacular mammals, and to some extent, these so-called charismatic megavertebrates are still the best vehicles for conveying the entire issue of conservation to the public. They are really our flagship species, both here in the United States and in the developing countries, and primates in particular are perhaps the best flagships for tropical forest conservation. Nonhuman primates are of particular interest in this context for three basic reasons: they are of great importance to our own species; they are largely a tropical order, roughly 90% of all primate species being restricted to the tropical forest regions of Asia, Africa, and the Neotropics; and they are members of the elite group called the charismatic megavertebrates. The threats to primates and their tropical forest habitats can be seen by examining two tropical forest regions: Brazil, particularly the Atlantic forest region of eastern Brazil, and the island of Madagascar. These are clearly two of the most important countries for primate conservation, and they are among the world’s richest countries for living organisms in general—countries that I call the megadiversity countries and that are critical to the survival of the majority of the world’s biological diversity. Most people are aware of the importance of the Order Primates, which of course includes our own species, Homo sapiens. However, few realize how diverse the Order of Primates actually is, including as it does some 200 species that range from the tiny mouse lemur (Microcebus murinus) of Madagascar and the tarsiers (Tarsius spp.) of Southeast Asia to the great apes, which include our closest living relatives, the chimpanzee (Pan troglodytes) and the pygmy chimpanzee (Pan paniscus). Our
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BioDiversity nonhuman primate relatives are valuable to us in many ways, and the rapid growth of the science of primatology over the past 25 years has reflected this. Studies of these animals have taught us a great deal about the intricacies of our own behavior, they have clarified questions about our evolution and our origins, and they have played a significant role in biomedical research. Furthermore, the importance of primates as key elements of the tropical forest (e.g., seed dispersers) is only starting to be understood. Unfortunately, wild populations of most nonhuman primates are decreasing all over the world. Many spectacular species like the mountain gorilla (Gorilla gorilla beringei) from Rwanda, Uganda, and Zaire, the golden lion tamarin (Leontopithecus rosalia) and the muriqui (Brachyteles arachnoides) from Brazil, and the indri (Indri indri) and the aye-aye (Daubentonia madagascariensis) from Madagascar are already endangered, and many others are headed in the same direction. Without a doubt, the major cause of the decline of primate populations is destruction of their tropical forest habitat, which is occurring at a rate of some 10 to 20 million hectares per year (OTA, 1984), the latter figure being equivalent to a loss of an area the size of California every 2 years. Another very important factor in the decline of these populations is hunting of primates, mainly as a source of food, but these animals are also hunted for their supposed medicinal value, for the ornamental value of their skins and other body parts, and for their use as bait for other animals, or to eliminate them from agricultural areas where they have become crop raiders. The effects of hunting vary greatly from region to region and from species to species, but hunting of primates as food is known to be a very serious threat in at least three parts of the world—the Amazonian region of South America, West Africa, and Central Africa. Many thousands of primates are killed every year in these regions for culinary purposes, and such overhunting has already resulted in the elimination of certain species from large areas of otherwise suitable forest habitat (e.g., the elimination of woolly monkeys and spider monkeys in Amazonia) (Mittermeier, 1987; Mittermeier et al., 1986). Live trapping of primates, either for export or for local use, plays an important role as well. Live primates are used in biomedical research and testing, or they may be sold as pets or exhibits, both internationally and within their countries of origin. For the most part, this is a less important factor than habitat destruction or hunting, but for certain endangered and vulnerable species that happen to be in heavy demand, it can be quite serious. Species that have been hurt by the trade in live primates include the chimpanzee and the cotton-top tamarin (Saguinus oedipus), both of which were important biomedical research models, and the woolly monkeys (Lagothrix spp.), which were and still are very popular as pets for local people in Amazonia. All these factors have combined to bring about a worldwide decline in primate populations. According to the International Union for Conservation of Nature (IUCN), one out of every three of the world’s 200 primate species is already in some danger and one in seven is highly endangered and could be extinct by the turn of the century or even sooner if something isn’t done quickly. These are minimum estimates. Very often when specialists go into the field to investigate
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BioDiversity the status of poorly known species, they find it necessary to add to the endangered list. To prevent the extinction of the world’s nonhuman primates, the Primate Specialist Group of IUCN’s Species Survival Commission put together a Global Strategy for Primate Conservation in 1977. This document (Mittermeier, 1977) was the first effort to take a worldwide view of primate conservation problems, and its purpose was to make the Primate Specialist Group’s goal of maintaining the current diversity of the Order of Primates a reality. It placed dual emphasis on ensuring the survival of endangered species wherever they occur and on providing effective protection for large numbers of primates in areas of high primate diversity or abundance. This original Global Strategy, which is now out of date, is being updated by a series of new regional plans for Africa (Oates, 1986), Asia (Eudey, 1987), Madagascar, and the Neotropical region, which will guide primate conservation activities for the remainder of this decade. To find the financial support for the activities identified in the original Global Strategy, the World Wildlife Fund established a special Primate Program in 1979. Since that time, the program has funded and helped implement more than 150 projects, large and small, in 31 different countries, and it continues to grow. In addition, the program produces a wide variety of educational materials and publishes Primate Conservation, the newsletter and journal of the IUCN/SSC Primate Specialist Group, which is the major means of communication among the world’s primate conservationists. A number of other organizations have also helped to support projects identified by the Primate Specialist Group, among them the New York Zoological Society, the Wildlife Preservation Trust International, the African Wildlife Foundation, the Fauna and Flora Preservation Society, the Brookfield Zoo, and the Frankfurt Zoological Society, to name just a few. Although the combined efforts of the World Wildlife Fund Primate Program and the other organizations have achieved a great deal on behalf of primates over the past decade, it is clear that much more will have to be done over the next few years to ensure that all of the world’s 200 primate species are still with us as we enter the next century. Two tropical countries, Brazil and Madagascar, are particularly important in efforts to conserve primate diversity, since they alone are home to 40% of the world’s living primate species. Brazil, with 357 million hectares of tropical forest, is by far the richest country in the world for this biome, containing more than three times more forest than the next country on the list, which is Indonesia, and 30% of all the tropical forest on our planet (Table 16–1). Not surprisingly, Brazil is also home to far more primates than any other country; its 53 species account for about 27%, or one in every four, primates in the world (Table 16–2). Although one usually hears much more about Amazonia, the highest priority area within Brazil is its Atlantic forest region, which is the most developed and most devastated part of the country. The Atlantic forest is a unique series of ecosystems quite distinct from the much more extensive Amazonian forests to the northwest. At one time, it stretched pretty much continuously from the state of Rio Grande do Norte at the easternmost tip of South America out as far as Rio Grande do Sul, the southernmost state in Brazil, and it included some of the
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BioDiversity TABLE 16–1 Countries of the World Containing the Largest Areas of Closed Tropical Foresta Country Areas of Closed Forest (hectares) Brazil 357,480,000 Indonesia 113,895,000 Zaire 105,750,000 Peru 69,680,000 India 51,841,000 Colombia 46,400,000 Mexico 46,250,000 Bolivia 44,010,000 Papua New Guinea 34,230,000 Burma 31,941,000 Venezuela 31,870,000 Congo 21,340,000 Malaysia 20,995,000 Gabon 20,500,000 Guyana 18,475,000 Cameroon 17,920,000 Suriname 14,830,000 Ecuador 14,250,000 Madagascar 10,300,000 aFrom OTA, 1984, and Mittermeier and Oates, 1985. richest, tallest, and most beautiful forest on Earth. In its primeval state, the Atlantic forest complex covered over 1 million square kilometers in 14 states or about 12% of Brazil, and its length from north to south extended a greater distance than the entire Atlantic seaboard of the United States from northern Maine to the Florida Keys. However, this region was the first part of Brazil to be colonized, it has developed into the agricultural and industrial center of the country, and it has within its borders two of the three largest cities in all of South America—Rio de Janeiro and São Paulo, which is now one of the largest cities on Earth. The result has been large-scale forest destruction, especially in the last two decades of rapid economic development, to obtain lumber and charcoal and to make way for plantations, cattle pasture, and industry—to the point that only 1 to 5% of the original forest remains in this region. As might be expected, the animals and plants native to the Atlantic forest are not doing very well under such circumstances. Many of these are endemic (including 40% of all the small, non-volant, i.e., nonflying, mammals, 54% of the trees, and 64% of the palms), and increasing numbers are being added to the endangered species list. The best example is probably the effect on the primates, 80% of which are endemic to the Atlantic forest. Twenty-one species and subspecies of monkeys are found in this region, and the studies that have been carried out with World Wildlife Fund support since 1979 indicate that fully 14 of these are endangered and that several are literally on the verge of extinction. Of these 14 endangered species, 13 are found nowhere else in the world (Mittermeier et al., 1986).
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BioDiversity Two of the Atlantic forest primate species stand out among the rest: the muriqui (Brachyteles arachnoides), which is the largest and most apelike of the South American monkeys, and the golden lion tamarin (Leontopithecus rosalia), which is surely one of the most beautiful of all mammals. These animals are representatives of the two highly endangered genera that are endemic to the Atlantic forest, and they have been subjects of two major public awareness campaigns that have been under way for the past 5 years (Dietz, 1985; Mittermeier et al., 1985). They have really become the flagship species for the entire region, and the campaigns using them as symbols are excellent examples of the way in which key groups of animals can be used to sell the whole issue of conservation, both in the tropical countries and in the developed world. The campaigns for the muriqui and the golden lion tamarin have been multifaceted, including ecological research, survey work, development of museum exhibits, production of films, and distribution of a wide variety of educational and promotional materials, including posters, stickers, T-shirts, and various publications. The result is that these two species, which were virtually unknown to the general public in Brazil 5 years ago, are now so popular that they appear on the cover of phone books, on postage stamps, as themes of parades and theater presentations, and as subjects of numerous magazine and newspaper articles. All this, and of course a broad spectrum of some 50 other conservation projects being supported by the World Wildlife Fund in this region, has led to a general increase in conservation awareness, which we hope will be instrumental in helping to save what remains of the Atlantic forest and its spectacular fauna and flora. The situation in Madagascar is even more critical than in the Atlantic forest region of eastern Brazil. Madagascar is a unique evolutionary experiment and a living laboratory that is unlike anyplace else on Earth. The island has been separated TABLE 16–2 Countries of the World Containing the Greatest Primate Diversitya Country No. of Species No. of Genera Brazil 52 16 Indonesia 33–35 9 Zaire 29–32 13–15 Madagascar 28 13 Cameroon 28–29 14 Peru 27 12 Colombia 27 12 Nigeria 23 13 Congo 22 14 Equatorial Guinea 21–22 12 Central African Republic 19–20 11–12 Gabon 19 11 Uganda 19 11 Bolivia 17–18 11–12 Angola 18–19 10–11 aModified from Mittermeier and Oates, 1985.
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BioDiversity TABLE 16–3 Primate Endemism in the 15 Countries With the Greatest Primate Diversity Country Endemic Species (%) Endemic Genera (%) Madagascar 93 92 Indonesia 44–50 12.5 Brazil 35 12.5 Colombia 11 0 Peru 7 0 Zaire 6–7 0 Nigeria 4 0 Cameroon 0 0 Congo 0 0 Equatorial Guinea 0 0 Central African Republic 0 0 Gabon 0 0 Uganda 0 0 Bolivia 0 0 Angola 0 0 from the African mainland for perhaps as long as 200 million years, if in fact it was ever connected, and most of the plant and animal species found there have evolved in isolation and are unique to the island. The most striking and conspicuous animals on Madagascar are the primates, which consist entirely of lemurs. Among these lemurs are some of the most unusual primates on Earth, ranging from the mouse lemur, which is the smallest living primate, to the indri, which is the largest living prosimian, and the aye-aye, which is the strangest of all primates and the only representative of an entire primate family, the Daubentoniidae. This lemur radiation on Madagascar is one of the most diverse primate faunas anywhere, its 29 species placing it fourth on the world list of primate diversity behind Brazil, Zaire, and Indonesia (even though it is only 7% the size of Brazil, Table 16–2). When endemism is considered, Madagascar’s primate fauna seems even more impressive, since 93% of all its species are restricted to that country—a figure not even approached by any other country (Table 16–3). Furthermore, the two lemur species found outside Madagascar reside only on the nearby Comoros Islands and are probably recent introductions by humans. The situation is much the same for most other groups of organisms in Madagascar. Seven of the eight species of carnivores found there are endemic, as are 29 of the 30 tenrecs, 106 of the 250 birds, 233 of the 245 reptiles, 142 of the 144 frogs, 110 of the 112 species of palms, and 80% of its nearly 8,000 angiosperm plants. It is not just endemism that is impressive on Madagascar, however, but total diversity as well. Although Madagascar is only about 40% again as large as the state of California and accounts for less than 2% of the African region, its 8,000 angiosperm plants represent 25% of all angiosperms in Africa (P.Lowry, personal communication, 1987), it has more orchids than the entire African mainland, and its 13 living primate genera approach the 14 to 15 mainland genera in total diversity.
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BioDiversity Unfortunately, most of Madagascar’s spectacular fauna and flora is endangered, mainly, once again, because of forest destruction. Although human beings arrived on Madagascar only some 1,500 to 2,000 years ago, human activity has resulted in the loss of some 80% of Madagascar’s forests, and the major remaining forest formations are being chipped away for firewood and charcoal and for slash-and-burn agriculture. Hunting is a problem as well, especially with the breakdown of local cultures, which formerly included many taboos against the hunting of primates and other wildlife. Lest anyone believe that extinctions are a figment of the conservationist’s imagination, he or she need only look at what has already been lost on Madagascar over the past 2,000 years. Among the species that have disappeared are the elephant birds (Aepyornis spp.), which were the largest birds that ever lived, a pygmy hippopotamus, an aardvark, and fully six genera of lemurs, representing one-third of all known Malagasy lemur species. Included among the species lost are animals like Megaladapis (Figure 16–1), which moved like a huge koala and grew to be as large as a female gorilla (Sussman et al., 1985). Almost all the species that have already disappeared were diurnal and larger than the surviving species. If this trend continues, the next in line would be the indri, which is the largest, and the sifakas (Propithecus spp.), which are next in size. In fact, several of these are already endangered. One, the black sifaka (Propithecus diadema perrieri) from northeastern Madagascar, is now down to only about 100 individuals and must be considered on the verge of extinction. FIGURE 16–1 Above: The extinct giant lemur Megaladapis from Madagascar, as reconstructed by Stephen D.Nash. Left: An extant ring-tailed lemur in Madagascar.
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BioDiversity At present, about 40% of Malagasy lemurs are considered endangered and many more are likely to enter the endangered category as we learn more about them. And what is happening to lemurs is happening to the rest of Madagascar’s fauna and flora as well. Despite the many problems, there is cause for optimism in Madagascar. In November 1985, a special National Conservation Strategy Conference held there attracted representatives from many international organizations, including IUCN, the World Wildlife Fund, the United Nations Environment Program, the Food and Agriculture Organization, the World Bank, and a number of bilateral aid organizations, including the U.S. Agency for International Development. This conference generated a great deal of enthusiasm for conservation among the Malagasy themselves and should serve as an important take-off point for future conservation activities. Several projects supported by the World Wildlife Fund are also serving as models for community involvement in conservation, and are attracting international attention to the need for conservation in this all-important country. Of particular importance in this respect is the Beza-Mahafaly project in southwestern Madagascar, which is being conducted by researchers from the University of Madagascar, Yale University, Washington University, and the Missouri Botanical Garden (Sussman et al., 1985). To be sure, a great deal still needs to be done in Madagascar to ensure that the country’s amazing biological diversity is maintained for future generations. Nevertheless, the time appears to be ripe to accomplish something of major proportions there and in effect to change the course of conservation history in this unique country. As indicated in Table 16–2, there is a very disproportionate distribution of primate diversity in the world. Just four countries, Brazil, Madagascar, Zaire, and Indonesia, by themselves account for approximately 75% of all the world’s primate species. If we are going to maintain global primate diversity, we must pay special attention to these countries over the next few decades, not to the exclusion of others but certainly more than we have in the past. Needless to say, these megadiversity countries are not just important for primates. Although we are still in the process of compiling data, it appears that approximately 50 to 80% of the world’s total biological diversity will be found in some 6 to 12 tropical countries. The first 6 of these to have emerged from the preliminary analysis are Brazil, Colombia, Mexico, Zaire, Madagascar, and Indonesia (see Figure 16–2). Not only do these countries have a major portion of the world’s biological diversity, they have an even higher percentage of the world’s diversity at risk—the very diversity that is in danger of disappearing over the next decade and that is of so much concern to conservation biologists. All these countries are undergoing rapid environmental change, are facing severe economic problems, and in general, lack the resources to develop the broad-based conservation programs needed to conserve biological diversity on their own. This means that people of the developed world are going to have to work in much closer collaboration with colleagues in these countries in the years to come and that the developed countries will have to provide far more resources for conservation than ever before.
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BioDiversity FIGURE 16–2 Megadiversity countries identified by the World Wildlife Fund. I do not believe in a gloom-and-doom approach to conservation, which can be quite detrimental to our efforts. On a more upbeat note, I believe that much of our planet’s biological diversity can be maintained and that conservation in general has to be considered the art of the possible. The example of Brazil, which may be the single most diverse country in the world, is most encouraging. One hears a great deal about destruction and the many environmental problems faced by Brazil but very little about the successes. Nonetheless, the successes are there, and for those of us who have been working in Brazil for two decades, the advances in conservation in that country seem little short of phenomenal. They lead me to believe that a very large proportion of Brazil’s biological diversity can be maintained. With the proper input of resources from both the developed world and the developing countries themselves, there is no reason why these successes cannot be repeated on a global basis. REFERENCES Dietz, L.A. 1985. Captive-born lion tamarins released into the wild: A report from the field. Primate Conserv. 6:21–27. Eudey, A.A. 1987. Action Plan for Asian Primate Conservation. International Union for the Conservation of Nature and Natural Resources/Species Survival Commission Primate Specialist Group, World Wildlife Fund, and United Nations Environment Programme, Washington, D.C. 70 pp. Mittermeier, R.A. 1977. A Global Strategy for Primate Conservation. International Union for the Conservation of Nature and Natural Resources/Species Survival Commission Primate Specialist Group, Cambridge, Mass. 325 pp. Mittermeier, R.A. 1987. The effects of hunting on rain forest primates. Pp. 109–146 in C.Marsh and R.A.Mittermeier, eds. Primate Conservation in the Tropical Rain Forest. Alan R.Liss, New York. Mittermeier, R.A., and J.F.Oates. 1985. Primate diversity: The world’s top countries. Primate Conserv. 5:41–48.
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BioDiversity Mittermeier, R.A., C.Valle, I.B.Santos, C.Alves, C.A.Machado Pinto, and A.F.Coimbra-Filho. 1985. Update on the muriqui. Primate Conserv. 5:28–30. Mittermeier, R.A., J.F.Oates, A.A.Eudey, and J.Thornback. 1986. Primate conservation. Pp. 3–72 in G.Mitchell and J.Erwin, eds. Comparative Primate Biology, Vol. 2A, Behavior, Conservation and Ecology. Alan R. Liss, New York. Oates, J.F. 1986. Action Plan for African Primate Conservation. International Union for the Conservation of Nature and Natural Resources/Species Survival Commission Primate Specialist Group, World Wildlife Fund and United Nations Environment Programme, Washington, D.C. 41 pp. OTA (Office of Technology Assessment). 1984. Technologies to Sustain Tropical Forest Resources. Congress of the United States, Office of Technology Assessment, Washington, D.C. 344 pp. Sussman, R.W., A.F.Richard, and G.Ravelojaona. 1985. Madagascar: Current projects and problems in conservation. Primate Conserv. 5:53–59.
Representative terms from entire chapter: