Abstract
This paper describes four global-change phenomena that are having major impacts on Amazonian forests. The first is accelerating deforestation and logging. Despite recent government initiatives to slow forest loss, deforestation rates in Brazilian Amazonia have increased from 1.1 million ha yr−1 in the early 1990s, to nearly 1.5 million ha yr−1 from 1992–1994, and to more than 1.9 million ha yr−1 from 1995–1998. Deforestation is also occurring rapidly in some other parts of the Amazon Basin, such as in Bolivia and Ecuador, while industrialized logging is increasing dramatically in the Guianas and central Amazonia.
The second phenomenon is that patterns of forest loss and fragmentation are rapidly changing. In recent decades, large-scale deforestation has mainly occurred in the southern and eastern portions of the Amazon — in the Brazilian states of Pará, Maranhāo, Rondônia, Acre, and Mato Grosso, and in northern Bolivia. While rates of forest loss remain very high in these areas, the development of major new highways is providing direct conduits into the heart of the Amazon. If future trends follow past patterns, land-hungry settlers and loggers may largely bisect the forests of the Amazon Basin.
The third phenomenon is that climatic variability is interacting with human land uses, creating additional impacts on forest ecosystems. The 1997/98 El Niño drought, for example, led to a major increase in forest burning, with wildfires raging out of control in the northern Amazonian state of Roraima and other locations. Logging operations, which create labyrinths of roads and tracks in forsts, are increasing fuel loads, desiccation and ignition sources in forest interiors. Forest fragmentation also increases fire susceptibility by creating dry, fire-prone forest edges.
Finally, recent evidence suggests that intact Amazonian forests are a globally significant carbon sink, quite possibly caused by higher forest growth rates in response to increasing atmospheric CO2 fertilization. Evidence for a carbon sink comes from long-term forest mensuration plots, from whole-forest studies of carbon flux and from investigations of atmospheric CO2 and oxygen isotopes. Unfortunately, intact Amazonian forests are rapidly diminishing. Hence, not only is the destruction of these forests a major source of greenhouse gases, but it is reducing their intrinsic capacity to help buffer the rapid anthropogenic rise in CO2.
References
Abramovitz, J.: 1998, Taking a Stand: Cultivating a New Relationship with the World's Forests. World Watch Institute, Washington, D.C.
Anon.: 1995, Japanese logging in Bolivia: An Analytical Review of the Operations of Industria Maderera Suto Ltd. and its Social and Environmental Impacts. Report by the Japan-Brazil Network, Rainforest Action Network, 26 April 1995.
Anon.: 1997a, Controle sobre florestas exige a reforma do IBAMA. A Critica (Manaus, Brazil), 19 January 1997.
Anon.: 1997b, A rain forest imperiled. Editorial, The New York Times, 15 October 1997.
Anon.: 1997c, Malaysian loggers in the Amazon. Action Albert, Rainforest Action Network, 24 February 1997.
Anon.: 1998a, NGOs press for more forest reserves. Inter-Press Service, 23 December 1998.
Anon., 1998b, Brazil's rainforest plan under fire. Associated Press, 25 November 1998.
Anon.: 1998c, House approves debt relief for tropical forest conservation. Associated Press, 19 March 1998.
Bennett, E. L.: 1996, In: Effects of Logging on Wildlife in the Tropics (proceedings of a conference sponsored by BOLFOR [Bolivia] and Wildlife Conservation Society [New York]).
Brasil, K.: 1996, Madeireiras asiáticas desrespeitam leis no AM, O Estado de S. Paulo, São Paulo, Brazil, 14 August 1996.
Brown, N.: 1998. Trends Ecol. Evol. 13, 41.
Christie, M.: 1997, ‘Green groups frown as Brazil auctions off jungle,’ Reuters News Service, 4 August 1997.
Cochrane, M. A., Schulze, M. D.: 1998, Conserv. Biol. 12, 948-950.
de Cassia, R.: 1997, BR-174: FHC anuncia abertura de nova frontiera agricola no norte. Amazonas em Tempo (Manaus, Brazil), 25 June 1997.
Dale, V. H., Pearson, S. M.: 1997, In: W. F. Laurance and R. O. Bierregaard, Jr., eds., Tropical Forest Remnants: Ecology, Management, and Conservation of Fragmented Communities. University of Chicago Press, Chicago, pp. 400-409.
Enting, I. G., Trudinger, C. M., Francey, R. J.: 1995, Tellus 47B, 35-53.
Epstein, J., Moore, L.: 1997, Far East goes deep south. Latin Trade Magazine, July 1997, pp. 61-66.
Fan, S., Gloor, M., Mahlman, J., et al.: 1998, Science 282, 442-446.
Fearnside, P. M.: 1987, Conserv. Biol. 1, 214-221.
Fearnside, P. M. 1990, In: A. B. Anderson, ed. Alternatives to Deforestation: Towards Sustainable Use of the Amazonian Rain Forest. Columbia University Press, New York, pp. 235-251.
Fearnside, P. M.: 1993, Ciencia Hoje 19, 6-8.
Fearnside, P. M.: 1995, Environ. Conserv. 22, 7-19.
Fearnside, P. M.: 1997a, Environ. Conserv. 24, 303-306.
Fearnside, P. M.: 1997b, Mitigation Adapt. Strat. Global Change 2, 285-302.
Fearnside, P. M., Leal-Filho, N.: In press. In: R. O. Bierregaard, Jr., et al., eds. Lessons from Amazonia: The Ecology and Conservation of a Fragmented Forest. Yale University Press, New Haven, Connecticut.
Ferreira, L. V., Laurance, W. F.: 1997, Conserv. Biol. 11, 797-801.
Grace, J., Lloyd, J., McIntyre, J., et al.: 1994, Science 270, 778-780.
Grieser Johns, A.: 1997, Timber Production and Biodiversity Conservation in Tropical Rain Forests. Cambridge Univ. Press, Cambridge, U.K.
Holmes, B.: 1996, New Scientist 151(2048), 43.
Houghton, R. A.: 1991, Climatic Change 19, 99-118.
Houghton, R. A.: 1996, Tellus 48B, 419-432.
INPE: 1996, ‘Deforestation Estimates in the Brazilian Amazon, 1991–1994.’ Instituto Nacional de Pesquisas Espaciais, San Jose dos Campos, Brazil.
INPE: 1998, ‘Deforestation Estimates in the Brazilian Amazon, 1995–1997.’ Instituto Nacional de Pesquisas Espaciais, San Jose dos Campos, Brazil.
Ito, T. M., Loftus, M.: 1997, ‘Cutting and dealing.’ U.S. News and World Report, 3 October 1997.
Kapos, V.: 1989, J. Trop. Ecol. 5, 173-185.
Keller, M., Clark, D. A., Clark, D. B., et al.: 1996, Science 273, 201.
Laurance, W. F.: 1998, Trends Ecol. Evol. 13, 411-415.
Laurance, W. F.: 1999, ‘Gaia's lungs: Are the rainforests inhaling earth's excess carbon dioxide?’ Natural History Magazine, March 1999, p. 96.
Laurance, W. F., Ferreira, L. V., Rankin de Merona, J. M., et al.: 1998a, Ecology 79, 2032-2040.
Laurance, W. F., Laurance, S. G.: 1997, Biotropica 28, 310-322.
Laurance, W. F., Laurance, S. G., Delamonica, P.: 1998b, Forest Ecol. Manage. 110, 173-180.
Laurance, W. F., Laurance, S. G., Ferreira, L. V., et al.: 1997, Science 278, 1117-1118.
Laurance, W. F., Williamson, G. B., Delamonica, P., et al.: Submitted, Science.
Lean, J., Warrilow, D. A.: 1989. Nature 342, 411-413.
Leighton, M.: 1986. In: G. T. Prance, ed., Tropical Rain Forests and the World Atmosphere, Cambridge University Press, Cambridge, England, pp. 75-102.
Malhi, Y., Baldocci, D. D., Jarvis, P. G.: In press, Plant. Cell and Environment.
Malhi, Y., Nobre, A. D., Grace, J., et al.: 1998, J. Geophys. Res. Atmospheres 103(D24), 31593-31612.
Meggers, B. J.: 1994, Climatic Change 28, 321-338.
Nepstad, D. C.: 1998, ‘Origin, incidence, and implications of Amazon fires.’ U.S. Global Change Research Program Seminar Series, U.S. Global Change Program, Washington, D.C., 30 March 1998.
Nepstad, D. C., Klink, C. A., Uhl, C., et al.: 1997, Ciencia e Cultura 49, 73-86.
Nepstad, D. C., Moreira, A., Verissimo, A., et al.: 1998, Conserv. Biol. 12, 951-955.
Nobre, C. A., Sellers, P. J., Shukla, J.: 1991, J. Climate 4, 957-988.
Phillips, O. P., Malhi, Y., Higuchi, N., Laurance, W. F., et al.: 1998, Science 282, 439-442.
Rayner, P. J., Enting, I. G., Francey, R. J., Langenfelds, R.: In press, Tellus.
Schimel, D. S.: 1995, Global Change Biol. 1, 77-91.
Schomberg, W.: 1998a, ‘Amazon fire risk rises due to logging, farmers.’ Reuters News Service, 15 March 1998.
Schomberg, W.: 1998b, ‘Brazil introduces new law to protect environment.’ Reuters News Service, 13 February 1998.
Schomberg, W.: 1999, ‘Brazil suspends issuing of Amazon clearing permits.’ Reuters News Service, 12 February 1999.
Shukla, J., Nobre, C. A., Sellers, P.: 1990, Science 247, 1322-1325.
Skole, D., Tucker, C. J.: 1993, Science 260, 1905-1910.
Uhl, C., Buschbacher, R.: 1985, Biotropica 17, 265-268.
Uhl, C., Kauffman, B.: 1990, Ecology 71, 437-449.
Verissimo, A., Barreto, M., M. Mattos, et al.: 1992, Forest Ecol. Manage. 55, 169-199.
Vitousek, P. M., Aber, J. D., Howarth, R. W., et al.: 1997, Ecol. Applic. 7, 737-750.
Walker, G.: 1996, New Scientist 151(2048), 40-42.
Whitmore, T. C.: 1997, In: W. F. Laurance and R. O. Bierregaard, Jr., eds., Tropical Forest Remnants: Ecology, Management, and Conservation of Fragmented Communities. University of Chicago Press, Chicago, pp. 3-12.
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Laurance, W.F. Mega-Development Trends in the Amazon: Implications for Global Change. Environ Monit Assess 61, 113–122 (2000). https://doi.org/10.1023/A:1006374320085
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DOI: https://doi.org/10.1023/A:1006374320085