Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 13 July 1984:
Vol. 225. no. 4658, pp. 129 - 138
DOI: 10.1126/science.225.4658.129
Prev | Table of Contents | Next

Articles

Amazon Basin: A System in Equilibrium

Eneas Salati 1 and Peter B. Vose 2

1 Director of the Centro de Energia Nuclear na Agricultura, University of São Paulo, C.P. 96, Piracicaba, 13400, São Paulo, Brazil
2 Project manager of the International Atomic Energy Agency Amazon Project and is also at the Centro de Energia Nuclear na Agricultura.

Despite the very active deforestation of the last decade, the Amazon Basin is still primarily covered with trees and is a system in equilibrium. The Andes form a barrier at the western end of the basin and, coupled with the prevailing easterly winds, ensure an almost unique precipitation and water-recycling regime. On average 50 percent of the precipitation is recycled, and in some areas even more. The soils are poor. Most of the nitrogen and phosphorus is found in the soil, and the remaining nutrient elements are found in the standing biomass. There is some nutrient recycling and little loss from the intact ecosystem, and the small input of nutrients from precipitation maintains a small positive nutrient balance. Continued large-scale deforestation is likely to lead to increased erosion and water runoff with initial flooding in the lower Amazon, together with reduced evapotranspiration and ultimately reduced precipitation. Reduced precipitation in the Amazon could increase the tendency toward continentality and adversely affect climate and the present agriculture in south-central Brazil.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Biodiversity Meets the Atmosphere: A Global View of Forest Canopies.
C. M. P. Ozanne, D. Anhuf, S. L. Boulter, M. Keller, R. L. Kitching, C. Korner, F. C. Meinzer, A. W. Mitchell, T. Nakashizuka, P. L. S. Dias, et al. (2003)
Science 301, 183-186
   Abstract »    Full Text »    PDF »
Tropical deforestation and climate change.
K. L. O'Brien and K. L. O'Brien (1996)
Progress in Physical Geography 20, 311-335
   Abstract »    PDF »
Tropical Deforestation and Habitat Fragmentation in the Amazon: Satellite Data from 1978 to 1988.
D. Skole, D. Skole, and C. Tucker (1993)
Science 260, 1905-1910
   Abstract »    PDF »
Biomass Burning in the Tropics: Impact on Atmospheric Chemistry and Biogeochemical Cycles.
P. J. Crutzen, P. J. Crutzen, and M. O. Andreae (1990)
Science 250, 1669-1678
   Abstract »    PDF »
Amazon Deforestation and Climate Change.
J. Shukla, J. Shukla, C. Nobre, and P. Sellers (1990)
Science 247, 1322-1325
   Abstract »    PDF »
Amazon River Discharge and Climate Variability: 1903 to 1985.
J. E. Richey, J. E. RICHEY, C. NOBRE, and C. DESER (1989)
Science 246, 101-103
   Abstract »    PDF »
Exchange of Materials Between Terrestrial Ecosystems and the Atmosphere.
H. A. Mooney, H. A. MOONEY, P. M. VITOUSEK, and P. A. MATSON (1987)
Science 238, 926-932
   Abstract »    PDF »
Hydrological interactions between the land surfaces and the atmosphere as a factor in climatic change.
J. G. Lockwood (1987)
Progress in Physical Geography 11, 103-111
   PDF »
Conservation in South America: Problems, Consequences, and Solutions.
M. A. Mares and M. A. MARES (1986)
Science 233, 734-739
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)