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Biodiversity (1988) / Chapter Skim
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Part 3: Diversity at Risk: Tropical Forests
Pages 117-154

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From page 119...
... 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.
From page 120...
... 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 ant]
From page 121...
... 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
From page 122...
... 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.
From page 123...
... 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 knowlecige about host specificity of insects in tropical forests.
From page 124...
... 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 subLypothesis that host specificity is a main feature of the lifestyle of tropical canopy insects.
From page 125...
... 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 try' FIGURE 13-1 The South American land mass.
From page 126...
... 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.
From page 127...
... 7 families / 2.6% n = 114 \ 7 families / Manaus/Tambopata Terra firme (Upland Forest Type 1) Distance = 1,500 km 8.7% Tambopata, Peru Upland Forest Type 1 Plots 1 and 2 Distance = 50 m Dry Season FIGURE 13-2 Pie diagrams of shared beetle species among forests in Peru and Brazil in percent of fauna.
From page 128...
... LiebLe, a member of the top predatory carabid beetle group in tropical forest canopies.
From page 129...
... 1982. Tropical forests: Their richness in Coleoptera and other Arthropod species.
From page 130...
... JANZEN University of Pennsylvania, Philadelphia, Pennsylvania r ~ , ~ he rain forest is not the most threatened of the major tropical forest types. The tropical dry forests hold this honor.
From page 131...
... Some species of animals feed on dry season fruits, seeds, and flowers; for them, the dry season is the bountiful time of year and the rainy season, inimical. DIVERSITY IN THE DRY FOREST What is the level of diversity in tropical dry forests?
From page 132...
... Tropical forests can be likened to libraries and books. The value of a book is not measured by the number of words it contains or even by the number of kinds of words it contains.
From page 133...
... A traditional conservation battle for tropical dry forests would have to have been fought in 1900. Today, restoration ecology and habitat management (e.g., Janzen, in press c)
From page 134...
... ~ Fires and invasion by grasses are the most serious contemporary ecological threats to the restoration and maintenance of dry forest wildlands. Properly manipulated, domestic animals may be the best tools for managing these threats, and they may even pay for their own maintenance: they mow the competing grass, they eat the fuel for the next dry season's grass fires, and they disperse tree seeds far into pastures.
From page 135...
... In Central America, the rain forest and the dry forest are the mutual recipients of each other's migrants migrants that are important parts of the interactive structure that holds tropical habitats together. Birds migrating from Wisconsin to Costa Rica are not the only ecological link over large agroscapes.
From page 136...
... will perturb ecological inter' actions substantially more and effect them more permanently in dry forests than in most extratropical or rain forest habitats. This calls for strict zoning for habitat use and replicate habitats, both of which can be compatible with conservation management only if a large acreage is set aside.
From page 137...
... Costa Rican Natural History. University of Chicago Press, Chicago.
From page 138...
... , Washington, D.C. Deforestation of tropical forests affects not only the plants and animals of these regions but also their human inhabitants.
From page 139...
... The several fields actively cultivated by the families of the community are generally cut in primary forest, though occasionally in secondary forest, and usually no more than a 2-hour walk from the settlement. In more distant fields, a second family house is built for temporary stays of 1 to 2 weeks cluring the dry season.
From page 140...
... The Kayapo Indians are probably not unique. More likely they are typical of indigenous societies in tropical forests.
From page 141...
... of this form of agriculture and discusses the various forms it can take, in terms of whether primary or secondary forest or grasslands are being used, crop~fallow time ratios, types of crop, dispersal relative to human settlements, concomitant presence of livestock, and tools and techniques used. It is unlikely that a form of agriculture so timehonored and widespread would be inefficient or destructive of the environment; yet many people regard it as just that as one way in which the remaining tropical forests are being destroyed.
From page 142...
... The point here is simply that the Indians who live in the forest and know its ecology so well have long ago demonstrated their ability to function as valuable and effective producers of its marketable resources. THE IMPACT OF DEFORESTATION ON INDIAN LIFE The destruction of the tropical forests has both a direct and an indirect impact on the resources and livelihood of Indian populations.
From page 143...
... They can produce a wide range of natural and cultivated products for the marketplace while still pursuing their way of life in and as part of the forest. When we speak of the preservation of the tropical forests we must make clear, explicitly and emphatically, that we mean the preservation of the forests' flora and their fauna and their indigenous human inhabitants.
From page 144...
... 1985. Indigenous management of tropical forest ecosystems: The case of the Kayapo Indians of the Brazilian Amazon.
From page 145...
... 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 islanc! of Madagascar.
From page 146...
... 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)
From page 147...
... Although the combined efforts of the World Wildlife Fund Primate Program and the other organizations have achieved a great clear 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 worId's living primate species.
From page 148...
... 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.
From page 149...
... 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 ~iXlorld 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.
From page 150...
... Among these femurs are some of the most unusual primates on Earth, ranging from the mouse femur, 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 femur 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~.
From page 151...
... 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-andburn 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.
From page 152...
... 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~.
From page 153...
... 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.
From page 154...
... 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.


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