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The trajectory of change and regional dynamics
A case cannot be made at this time that Amazonia is heading inexorably for criticality. This overall statement should not be taken to mean that environmental trends in the region are all positive and that no action is required to avert potentially serious environmental damage. The vast area encompassed by the basin, coupled with the extraordinary variation in cultures, economic conditions, and habitats, invites caution when discussing the overall situation. In some areas, environmental conditions are clearly becoming worse and the plight of some social groups, particularly Indians, appears to be worsening. Yet in other parts of Amazonia, an improvement in both living conditions and ecosystem health is evident.
Although the impact of environmental changes under way in Amazonia appears to be confined to the regional or local levels, forces of destruction are likely to increase in the future. Brazil's population is growing by some 3 million people a year, and efforts to open up Amazonia for settlement and development will inevitably intensify. With a return to a democratic form of government in Brazil, pent-up social pressures for land reform and more jobs will surely lead to greater currents of migration and the opening of forest to settlement and development projects. Indeed, threats to parks and reserves are increasing during the transition to full democracy, as politicians seek to curry favour with voters, both poor and rich, by "liberating" forest areas for occupation.
Many of the environmental issues related to development in Amazonia hinge on the scale and rates of deforestation. The period spanning the late 1960s to the mid-1980s witnessed a spurt in forest removal, associated in part with the opening of pioneer highways and investments in cattle-raising (Malingreau and Tucker 1988). The mid-1980s surge in deforestation in the Brazilian Amazon may have been connected with the formulation of Brazil's new constitution, which was passed in 1988 and calls for land reform and stricter environmental controls. Landowners' fears that unoccupied land might be confiscated may have triggered a clearing frenzy (Revkin 1990, 180). This widespread effort to tame Amazonia's wilderness and integrate the region into the national economy, particularly noticeable in Brazil, stirred concern about the future of the forest and raised the spectre of deleterious regional and global environmental change.
Considerable controversy has characterized the debate about deforestation rates in Amazonia (Bonalume 1989a). Different definitions of forest, the difficulty of separating advanced second growth from forest, and whether temporary or permanent forest removal figures in the equation have contributed to different scenarios and conclusions about the dangers of deforestation. Some groups may have exaggerated deforestation rates to further political aims, whereas others may have downplayed figures in order to encourage further development of the region. No attempt will be made here to sort out all the claims and counter-claims as to how much of the Amazonian forest has been truly "lost." Three main points, however, are worth emphasizing: the notion of virgin Amazonian forests is a myth; considerable areas of Amazonia are still in mature forest (particularly in the western and northern parts of the basin); and rates of deforestation appear to be declining (Bonalume 1989b, 1991).
Deforestation since 1985 has slowed in Rondônia, an acknowledged "hot spot" for forest destruction (Fearnside 1989). Satellite imagery reveals a drop of approximately 27 per cent in deforestation in the Brazilian Amazon from 1989 to 1990 alone. The precise causes of this slow-down are unclear, but the severe recession gripping Brazil, the blocking of substantial portions of savings accounts by the government, and the desire of farmers and ranchers to put second growth back into production or to upgrade weed-choked pastures are partly responsible. Forests have waxed and waned in the face of economic cycles in other regions, such as the Mediterranean (Westoby 1989, 64). Farmers and ranchers in the Altamira area of the Transamazon Highway, for example, are cutting more second growth than forest. A similar pattern prevails among middle-scale ranchers in the Paragominas area.
Increased pressures to protect parks and reserves and to enforce environmental regulations in Amazonia have probably had negligible impacts. The notion that the removal of fiscal incentives for cattle-ranching in the Brazilian Amazon has slowed deforestation is implausible. The implications that the recession is a major factor in the slow-down in forest destruction, if correct, are worrisome. When the economy resumes growth on any significant scale, deforestation rates could pick up again. Only by adequately raising living standards for broad segments of society and taking a more systematic approach to environmental protection will ecological problems in the region be alleviated.
Unless alternatives to deforestation are offered, any widespread effort to halt forest-clearing could lead to lowered food production and more unemployment. Because of depletion of soil nutrients, weed invasion, and the build-up of pests and diseases, many farmers periodically clear new fields from forest. Farming methods that minimize forest-clearing, such as agro-forestry, thus need to be perfected for various soil and other environmental conditions.
Environmental degradation, such as soil erosion and the loss of fisheries and genetic resources, has not progressed on a scale sufficiently large to undercut economic development at this point. Poverty in the region is still largely a problem of access to better roads, schooling, and medical care, rather than putting out environmental brushfires. In the aggregate, wealth in the Amazon region is increasing. Cities are growing with new industries, and the middle class has expanded substantially in the last 25 years. It is true that a large proportion of the rural and urban population remains poor, but people today are probably better off in absolute terms than before 1960. The proportion of poor may have actually shrunk as new opportunities have arisen for land ownership or employment.
Progress towards improved well-being declined in the 1980s in response to inflationary pressures in Brazil and a downturn in rates of growth in the global economy. When inflation reached over 1,000 per cent a year by the close of the 1980s, very few segments of the economy were expanding. Inflation slowed considerably with the change in government in March 1990, but it has since headed up. Unless the management of national and international economies improves, it will be difficult to secure gains in living standards.
Not all segments of Amazonian society have benefited from the impressive investments in improving infrastructure and services in the region. Overall, indigenous groups have reaped few rewards from economic development in the region. And new proprietors have driven some smallholder farmers with no land titles off the land. But both rural and urban poor undoubtedly have better access to services and to educational and job opportunities than their parents had when they were young. Except in a few isolated areas, environmental gradation has not yet seriously undermined the long-term capacity of the landscape to cater to the needs of this and future generations.
Although environmental deterioration is not so alarming as is often portrayed in the media, and well-being and incomes are generally improving in the region, the stakes are ever higher. As more Amazonian ecosystems are altered to make room for people and development projects, nutrient recycling pathways are interrupted, heat and water fluxes may change, and other unseen ecological chain reactions may be taking place. The assumption here is that, as forest and aquatic environments are increasingly altered, human activities could become increasingly vulnerable to ecological surprises.
As Amazonia is increasingly occupied and the tempo of resource extraction accelerates, management input will have to increase accordingly. As farmers switch from extensive slash-and-burn systems to more intensive cropping patterns in response to population pressure and increasing land values, even more sophisticated management is needed. Traditional agro-forestry systems are certainly complex, but modern mixed-cropping patterns must also make adjustments to market conditions as well as shifting biotic pressures. Modern farms are characterized by a more rapid turnover of crop varieties and other technologies, all of which require a finely tuned agricultural research and development system. Farmers could become vulnerable to serious production shortfalls if the R&D pipeline becomes inefficient (Plucknett and Smith 1986).
Thus far, only 2 per cent of the Brazilian Amazon is in parks, reserves, or national forests. Even the inclusion of Indian reserves leaves less than 4 per cent of the region nominally protected. Sizeable tracts of forest will survive into the next century only if forests can be managed on an economically and ecologically sustainable basis and farms, pastures, and plantations are made more productive. Sustainable agriculture and forestry that provide cash income will be crucial to the survival of substantial tracts of forest in the next century. Poverty is arguably the greatest enemy of Amazonian forests.
Given the inevitable pressure to develop and occupy the Amazon, careful management of forest resources and agricultural activities will become ever more urgent. Although research is under way on many fronts to further our understanding of Amazonian ecosystems and socioeconomic processes, much more needs to be learned if the region's resources are to be managed on a sound basis. The Amazonian flood plain, in particular, could be a major food-producing area for South America if more were known about how to tap its natural and cultural resources.
A better integration of research efforts across the many institutions conducting research within and outside of Amazonia would also help further our understanding of biodiversity patterns, sustainable agricultural practices, and the potential and impact of new technologies. Networking is poorly developed among Amazonian research institutions, ranging from basic and applied science to university centres. Networking can help avoid redundancy and can make more efficient use of resources, which is particularly important in countries with limited resources (Plucknett, Smith, and Ozgediz 1990). Fortunately, innovative farmers and ranchers and skilled researchers are adopting and developing new technologies to help overcome constraints to raising and sustaining agricultural and silvicultural yields in Amazonia. Although much more research and testing of agricultural technologies developed at scientific institutes and in farmers' fields is needed, ongoing efforts offer hope that many tracts of Amazonia's unique forests will survive.
If properly managed, a wide range of agricultural and silvicultural activities is possible in the region. Both smallholder farmers and corporate operations are achieving sustainable yields in various parts of the basin. The continued vitality of Amazonian agriculture will rest on controlling inflation, a deeper understanding of the natural history of Amazonian ecosystems, including man-made environments, and greater support for research at agricultural research stations, institutes for basic and applied research, and growing universities in the region.
This chapter has made an argument that some promising trends are under way in Amazonia that could help save more forest from the power saw and axe as well as provide more sustainable livelihoods for small-, medium-, and large-scale producers. Furthermore, the case suggests that the Amazon is not yet at a stage of criticality, although the definitions used in this volume would place the region in the endangered category. Amazonia is also an important environmental region, both regionally and globally, because of two main facets: its enormous biodiversity, and the fragility of many of its ecosystems.
The region's enormous wealth in species and genetic resources has already been pointed out. Policy makers may remain unimpressed. After all, some of the world's poorest people live in the world's richest biomass. In the short term, many land users in the region clear and burn wilderness for a variety of motives, with little thought to the genetic treasures and potential new plant and animal species that could be domesticated. How much will the Amazon be impoverished for future generations? Current economic models can hardly tackle this issue. Let us be honest at this point. We simply do not know the worth of forest currently being destroyed; all we can do is work hard to mitigate deforestation, primarily by raising standards of living and improving productivity, and by supporting research into this biological wonderland. And conservation? Unless the social needs of local people are met, most of the elaborate plans for parks and reserves will founder.
Research is essential for averting large-scale environmental catastrophes in Amazonia for two reasons. In comparison with its biological riches, little is yet known about Amazonian ecosystems and how they can be wisely managed. Second, heavily leached, infertile soils underlie vast stretches of Amazonian forests and other plant communities. More research needs to address how to manage these "problem" soils so that they remain productive without relying excessively on expensive and environmentally damaging inputs. Many farmers are already experimenting with novel crop combinations and land-management techniques, and stronger links among scientists, farmers, and NGOs are necessary to encourage this process. Ultimately, local people will decide the fate of the forest, and international policy makers should always address their needs and not impose solutions acceptable only to the first world.
Alvim, Paulo. 1990. Agricultura apropriada pare uso contínuo dos solos da região Amazonica. Espaço, Ambiente e Planejamento 2, no. 11: 3-71.
Anderson, A. B. 1987. Forest management issues in the Brazilian Amazon. Report to the Ford Foundation. New York: Ford Foundation.
Barbira-Scazzocchio, Françoise, ed. 1980. Land, people and planning in contemporary Amazonia: Proceedings of the Conference on the Development of Amazonia in Seven Countries, Cambridge, 23-26 September, 1979. Centre of Latin American Studies, Occasional Publication no. 3. Cambridge: Cambridge University.
Bennett, C., G. Budowski, H. Daugherty, L. Harris, J. Milton, H. Popenoe, N. Smith, V. Urrutia, and E. Beltrán. 1974. Interaction of man and tropical environments. In Fragile ecosystems: Evaluation of research and applications in the neotropics, ed. Edward G. Farnworth and Frank B. Golley, 139-182. New York: Springer-Verlag.
Bonalume, R. 1989a. Rainforests: Destruction area disputed. Nature 339: 86.
Bonalume, R. 1989b. Amazonian forests: Burning continues, slightly abated. Nature 339: 569.
Bonalume, R. 1991. Deforestation rate is falling. Nature 350: 368.
Bramble, B. J. 1987. The debt crisis: The opportunities. Ecologist 17, no. 4/5: 192-199.
Braunschweiler, H. 1991. Provisional report for the Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq about the Project of Mercury Load in the Tucurui Lake and Surrounding Areas. Belém Brazil: Instituto de Pesquisas Ecologicas da Amazonia.
Brown, Lester R. 1991. The new world order. In State of the World: A Worldwatch Institute Report on Progress Toward a Sustainable Society, ed. Lester R. Brown et al., 3-20. New York: W. W. Norton.
Bunker, Stephen G. 1985. Underdeveloping the Amazon: Extraction, unequal exchange, and the failure of the modern state. Urbana, IL: University of Illinois Press.
Cleary, David. 1990. Anatomy of the Amazon gold rush. Iowa City: University of Iowa Press.
Crist, R. E. 1967. Quelques aspects des migrations humaines et de la colonisation en Amérique Latine. In Les problèmes agraires des Amériques Latines, Paris, 11-16 octobre 1965, 501-510. Colloques Internationaux du Centre National de la Recherche Scientifique. Paris: Editions Centre.
Dean, Warren. 1987. Brazil and the struggle for rubber: A study in environmental history. Cambridge: Cambridge University Press.
Domning, D. P. 1982. Commercial exploitation of manatees Trichechus in Brazil c. 1785-1973. Biological Conservation 22: 101-126.
Eidt, R. C. 1962. Pioneer settlement in eastern Peru. Annals of the Association of American Geographers 52: 255-278.
Falesi, Italo Claudio. 1976. Ecosystema de pastagem cultivada na Amazônia brasileira. Boletim Técnico no. 1. Belém, Brazil: Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA).
Falesi, Italo Claudio, Antonio Ronald Camacho Baena, and Saturnino Dutra. 1980. Consequências do exploração agropecuária sobre as condições des físicas e químicas dos solos microregiões de Nordeste Paraense. Boletim de Pesquisa no. 14. Belém, Brazil: EMBRAPA, Centro de Pesquisa Agropecuá do Trópico Úmido.
Fearnside, Phillip M. 1986. Human carrying capacity of the Brazilian rainforest. New York: Columbia University Press.
Fearnside, Phillip M. 1989. Deforestation in Brazilian Amazonia: The rates and causes of forest destruction. Ecologist 19: 214-218.
Ferreira, Alexandre Rodrigues. 1971. Viagem filosófica pelas capitanias do Grão Pará., Rio Negro, Mato Groso e Cuiaba. Vol. 2. Zoologia, Botânica. Rio de Janeiro: Conselho federal de culture.
Flavin, Christopher. 1989. Slowing global warming: A worldwide strategy. Worldwatch Paper 91. Washington DC: Worldwatch Institute.
Fowler, Cary, and Patrick R. Mooney. 1990. Shattering: Food, politics, and the loss of genetic diversity. Tucson, AZ: University of Arizona Press.
Gentry, A. H., and J. Lopez-Parodi, 1980. Deforestation and increased flooding of the Upper Amazon. Science 210: 1354-1356.
Godfrey, B. 1990. Boom towns of the Amazon. Geographical Review 80: 103-117.
Graaf, N. R. 1982. Sustained timber production in the tropical rainforest of Suriname. In Proceedings of the Joint Workshop on Management of Low Fertility Acid Soils of the American Humid Tropics, Paramaribo, Suriname, 23-26 November 1981, ed. J. F. Wienk and H. A. de Wit. San Jose, Costa Rica: Inter-American Institute for Cooperation in Agriculture (IICA).
Gradwohl, Judith, and Russell Greenberg. 1988. Saving the tropical forests. Washington DC: Island Press.
Hall, Anthony L. 1978. Drought and irrigation in north-east Brazil. Cambridge: Cambridge University Press.
Hecht, Susanna. 1985. Environment, development and politics: Capital accumulation and the livestock sector in eastern Amazonia. World Development 13, no. 6: 663-684.
Hecht, Susanna, and Alexander Cockburn. 1989. The fate of the forest: Developers, destroyers, and defenders of the Amazon. London: Verso.
Hemming, John, ed. 1985a. Change in the Amazon basin. Vol. 1, Man's impact on forests and rivers. Manchester: Manchester University Press.
Hemming, John, ed. 1985b. Change in the Amazon basin. Vol. 2, The frontier after a decade of colonisation. Manchester: Manchester University Press.
Hicks, James F., Herman E. Daly, Shelton H. Davis, and Maria de Lourdes de Freitas. 1990. Ecuador's Amazon region: Development issues and options. World Bank Discussion Papers 75. Washington DC: World Bank.
Hiraoka, M. 1980. Settlement and development of the Upper Amazon: The East Bolivian example. Journal of Developing Areas 14: 327-347.
Hiraoka, M., and S. Yamamoto. 1980. Agricultural development in the Upper Amazon of Ecuador. Geographical Review 70: 423-445.
Homma, Alfredo Kingo Oyama. 1989a. A extração de recursos naturals renováveis: O caso do extrativismo vegetal na Amazônia. Ph.D. dissertation. Viosa, Minas Gerais: Universidade Federal de Viosa.
Homma, Alfredo Kingo Oyama. 1989b. Perspectivas da economia extrativista vegetal na Amazônia. Belém Brazil: EMBRAPA, unpublished report.
Homma, Alfredo Kingo Oyama. 1991. A desmistificação do extrativismo vegetal na Amazonia. Paper presented at the Seminario Grandes Projetos, Desorganização e Reorganização do Espaco, Belém 3-5 April.
Homma, Alfredo Kingo Oyama, A. R. Teixeira Filho, and E. P. Magalhaès. 1991. Análise do preço da terra como recurso natural durável: O caso da Amazonia. Revista de economía e sociología rural (Brasilia) 29, no. 2: 103-116.
Kleinpenning, J. M. G. 1975. The integration and colonisation of the Brazilian portion of the Amazon basin. Nijmeegse Geografische Cahiers 4, Geografisch en Planologisch Instituut. Nijmegen, Netherlands: Katholieke Universiteit.
Lavelle, P. 1987. Biological processes and productivity of soils in the humid tropics. In The geophysiology of Amazonia: Vegetation and climate interactions, ed. Robert E. Dickinson, 175-214. New York: J. Wiley, for the United Nations University.
Ledec, George, and Robert Goodland. 1988. Wildlands: Their protection and management in economic development. Washington DC: World Bank.
Mahar, Dennis J. 1989. Government policies and deforestation in Brazil's Amazon region. Washington DC: World Bank.
Malingreau, J., and C. J. Tucker. 1988. Large-scale deforestation in the southeastern Amazon basin of Brazil. Ambio 17: 49-55.
Malm, O., W. C. Pfeiffer, C. M. M. Souza, and R. Reuther. 1990. Mercury pollution due to gold mining in the Madeira River basin, Brazil. Ambio 19: 11-15.
Martinelli, L. A., J. R. Ferreira, B. R. Forsberg, and R. L. Victoria. 1988. Mercury contamination in the Amazon: A gold rush consequence. Ambio 17, no. 4: 252-254.
Mee, Margaret. 1988. Margaret Mee: In search of flowers of the Amazon forests. Woodbridge, Suffolk, UK: Nonesuch Expeditions.
Mitchell, J. F. B., C. A. Senior, and W. J. Ingram. 1989. CO2 and climate: A missing feedback? Nature 341: 132-134.
Montecinos, C., and Michael A. Altieri. 1991. Status and trends in grass-roots crop genetic conservation efforts in Latin America. Berkeley, CA: Consorcio Latino Americano sobre Agroecologia y Desarrollo.
Moran, Emilio F. 1981. Developing the Amazon. Bloomington: Indiana University Press.
Moran, Emilio F. 1988. Following the Amazon highways. In People of the tropical rain forest, ed. Julie Sloan Denslow and Christine Padoch, 155-162. Berkeley: University of California Press.
Muller, Keith D. 1988a. The impact of agricultural mechanization on population and migration in South Brazil: The example of West Paraná. Latin American Studies (University of Tsukuba) 9: 59-86.
Muller, Keith D. 1988b. The impact of agricultural mechanization on land tenancy and farm size in South Brazil: The example of West Paraná. Latin American Studies (University of Tsukuba) 10: 181-210.
Myers, Norman. 1991. Tropical deforestation: The latest situation. Biotropica 41, no. 5: 282.
Nations, J. D., and D. I. Kromer. 1983. Central America's tropical rainforests: Positive steps for survival. Ambio 12, no. 5: 232-238.
Nelson, Michael. 1973. The development of tropical lands: Policy issues in Latin America. Baltimore, MD: Johns Hopkins University Press.
Norman, Colin. 1981. The god that limps: Science and technology in the eighties. New York: W. W. Norton.
NRC (National Research Council). 1981. The water buffalo: New prospects for an underutilized animal. Washington DC: National Research Council, National Academy Press.
Parsons, J. J. 1989. Forest to pasture: Development or destruction. In Hispanic lands and peoples: Selected writings of James J. Parsons, ed. William M. Denevan, 275-295. Dellplain Latin American Studies 23. Boulder, CO: Westview Press.
Pearce, F. 1990. Brazil, where the ice cream comes from. New Scientist 127, no. 1724: 45-48.
Penny, Norman D., and Jorge R. Arias. 1982. Insects of an Amazon forest. New York: Columbia University Press.
Peters, C. M., A. H. Gentry, and R. O. Mendelsohn. 1989. Valuation of an Amazonian rainforest. Nature 399: 655-656.
Plucknett, Donald L., and Nigel J. H. Smith. 1986. Sustaining agricultural yields: As productivity rises, maintenance research is needed to uphold the gains. Bioscience 36: 40-45.
Plucknett, Donald L., Nigel J. H. Smith, and Selcuk O. Ozgediz. 1990. Networking in international agricultural research. Ithaca, NY: Cornell University Press.
Radulovich, R. 1990. A view on tropical deforestation. Nature 346: 214.
Revkin, Andrew. 1990. The burning season: The murder of Chico Mendes and the fight for the Amazon rain forest. Boston: Houghton Mifflin.
Richey, J. E., C. Nobre, and C. Deser. 1989. Amazon River discharge and climate variability. Science 246: 101-103.
Rudel, T. K. 1983. Roads, speculators, and colonization in the Ecuadorian Amazon. Human Ecology 11, no. 4: 385-403.
Schmink, Marianne. 1988. A case study of the closing frontier in Brazil. In Power and poverty: Development and development projects in the Third World, ed. Donald W. Attwood, Thomas C. Bruneau, and John G. Galaty, 135-153. Boulder, CO: Westview Press.
Schmink, Marianne, and Charles H. Wood, eds. 1984. Frontier expansion in Amazonia. Gainesville, FL: University of Florida Press.
Schmink, Marianne, and Charles H. Wood, eds. 1987. The "political ecology" of Amazonia. In Lands at risk in the Third World: Local level perspectives, ed. Peter D. Little and Michael M. Horowitz, 3857. Boulder, CO: Westview Press.
Serrão, Emanuel Adilson S. 1986a. Pastagem em area de floresta no trópico úmido brasileiro: conhecimentos atuais. In Anais do Primeiro Simpósio do Trópico Umido, Belém, Pará, 12 a 17 de novembro de 1984, vol. 5: 147-174.
Serrão, Emanuel Adilson S. 1986b. Pastagens natives do trópico úmido brasileiro: Conhecimentos atuais. In Anais do Primeiro Simpósio do Trópico Úmido, Belém, Pará,, 12 a 17 de novembro de 1984, vol. 5:183-205.
Serrão, Emanuel Adilson S. 1990. Pasture development and carbon emission/accumulation in the Amazon. Paper presented at the Intergovernmental Panel on Climate Change (IPCC) Meeting on Gas Emission from Conversion of Tropical Forests. São Paulo: Universidade de São Paulo.
Serrão, Emanuel Adilson S., and A. K. O. Homma. 1989. A questão da sustentabilidade da pecuária substituindo florestas na Amazônia: A influencia de variveis agronómicas, ecological, economical, e socials. Unpublished manuscript.
Serrão, Emanuel Adilson S., and A. K. O. Homma. 1993. Brazil. In Sustainable agriculture and the environment in the humid tropics. Report for the Comminee on Agriculture Sustainability and the Environment in the Humid Tropics, National Research Council. Washington DC: National Academy Press.
Serrão, Emanuel Adilson S., and J. M. Toledo. 1988. Sustaining pasture-based production systems for the humid tropics. Paper presented at the Man and the Biosphere (MAB) Conference on Conversion of Tropical Forests to Pasture in Latin America, 4-7 October 1988, Oaxaca, Mexico.
Smith, Nigel J. H. 1974. Destructive exploitation of the South American river turtle. Yearbook of the Pacific Coast Geographers 36: 85-102.
Smith, Nigel J. H. 1980. Anthrosols and human carrying capacity in Amazonia. Annals of the Association of American Geographers 70, no. 4: 553-566.
Smith, Nigel J. H. 1981. Man, fishes, and the Amazon. New York: Columbia University Press.
Smith, Nigel J. H. 1982. Rainforest corridors: The transamazon colonization scheme. Berkeley: University of California Press.
Smith, Nigel J. H. 1995 (forthcoming). Human-induced landscape change in Amazonia and implications for development. In Principles, patterns, and processes: Some legacies of the Columbian exchange, ed. B. L. Turner II. Madrid: Consejo Superior de Investigaciones Científicas (CSIC).
Smith, Nigel J. H., and R. E. Schultes. 1990. Deforestation and shrinking crop gene pools in Amazonia. Environmental Conservation 17, no. 3: 227-234.
Smith, Nigel J. H., Paulo Alvim, Alfredo K. O. Homma, Emanuel Adilson S. Serrão, and Italo C. Falesi. 1991. Human-induced environmental changes in Amazonia. Global Environmental Change 1, no. 4 (September): 313-320.
Smith, Nigel J. H., J. T. Williams, Donald L. Plucknett, and J. P. Talbot. 1992. Tropical forests and their plants. Ithaca, NY: Comstock.
Spitler, A. 1987. Exchanging debt for conservation. Bioscience 37: 781.
Stearman, A. M. 1978. The highland migrant in lowland Bolivia: Multiple resource migration and the horizontal archipelago. Human Organization 37, no. 2: 180-185.
Sternberg, H. O'R. 1973. Development and conservation. Erdkunde 27, no. 4: 253-265.
Sternberg, H. O'R. 1987. Aggravation of floods in the Amazon River as a consequence of deforestation? Geografiska Annaler (Series A, Physical Geography) 69A, no. 1: 201-219.
SUDAM (Superintendência de Desenvolvimento da Amazônia). 1990. Ação governamental na Amazônia: Subsídios ao zoneamento ecológico-económico e ao piano de desenvolvimento da Amazônia. Belém,: Sudam.
Turner, B. L., II, William C. Clark, Robert W. Kates, John F. Richards, Jessica T. Mathews, and William B. Meyer, eds. 1990. The earth as transformed by human action. Global and regional changes in the biosphere over the past 300 years. Cambridge: Cambridge University Press with Clark University.
Uhl, Christopher, and I. C. G. Vieira. 1989. Ecological impacts of selective logging in the Brazilian Amazon: A case study from the Paragominas region of the state of Pará,. Biotropica 21, no. 2: 98-106.
Weinstein, Barbara. 1983. The Amazon rubber boom 1850-1920. Stanford, CA: Stanford University Press.
Wesche, Rolf, and Thomas Bruneau. 1990. Integration and change in Brazil's middle Amazon. Development International vol. 7. Ottawa: University of Ottawa Press.
Westoby, Jack C. 1989. Introduction to world forestry: People and their trees. Oxford: Basil Blackwell.
Williams, Michael. 1990. Forests. In The earth as transformed by human action: Global and regional changes in the biosphere over the past 300 years, ed. B. L. Turner II, William C. Clark, Robert W. Kates, John F. Richards, Jessica T. Mathews, and William B. Meyer, 179-201. Cambridge: Cambridge University Press with Clark University.
Wood, Charles H., and Jose Alberto Magro de Carvalho. 1988. The demography of inequality in Brazil. Cambridge Latin American Studies, vol. 67. Cambridge: Cambridge University Press.
Wood, Charles H., and Marianne Schmink. 1978. Blaming the victim: Small farmer production in an Amazon colonization project. In Changing agricultural systems in Latin America, ed. Emilio Moran, 77-93. Studies in Third World Societies, Publication No. 7. Williamsburg, VA: Department of Anthropology, College of William and Mary.
Wood, W. B. 1990. Tropical deforestation: Balancing regional development demands and global environmental concerns. Global Environmental Change 1, no. 1 (December): 23-41.