Amazon Rainforest
From Simple English Wikipedia, the free encyclopedia
The Amazon Rainforest is the forest that grows in the tropical and subtropical basin of the Amazon River.
The forest lies in a basin drained largely by the Amazon River, with 1100 tributaries. This basin was formed in the Paleozoic period, between 500 and 200 million years ago.
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[edit] Biodiversity
Wet tropical forests are the most species-rich biome, and tropical forests in the Americas are consistently more species rich than are African and Asian wet forests[1]. As the largest tract of tropical rainforest in the Americas, Amazonian rainforests have unparalleled biodiversity.
The region is home to ~2.5 million insect species, tens of thousands of plants, and some 2000 birds and mammals. The diversity of plant species is the highest on earth with some experts estimating that one square kilometre may contain over 75,000 types of trees and 150,000 species of higher plants. One square kilometre of Amazon rainforest can contain about 90,000 tons of living plants. This constitutes the largest collection of living plants and animal species in the world. One in five of all the birds in the world live in the rainforests of the Amazon. To date, an estimated 438,000 species of plants of economic and social interest have been registered in the region with many more remaining to be discovered or cataloged. (Note: Brazil has one of the most advanced laws to avoid biopiracy, but enforcing it is a problem.)
[edit] Amazonian forests as a store of carbon dioxide
More than one fifth of the Amazon Rainforest has already been destroyed. The forest which remains is threatened. People who care for the envirnoment warn about the loss of biodiversity. They also point out that releasing the carbon which is stored in the trees will increase global warming.
About 10% of the worlds carbon is stored in the Amazonian forest. [2] — on the order of 1.1 x 1011 metric tonnes of carbon [2]. Amazonian forests are estimated to have accumulated 0.62 ± 0.37 tonnes of carbon per hectare per year between 1975 and 1996 [3]. Fires related to Amazonian deforestation have made Brazil one of the biggest greenhouse gas producers. Brazil produces about 300 million metric tonnes of carbon dioxide a year; 200 million of these are from logging and burning in the Amazon (pdf file). In 1996, the Amazon was reported to have a 34 per cent increase in deforestation since 1992. A new report by a congressional committee says the Amazon is vanishing at a rate of 52,000 square kilometers (20,000 miles²) a year, over three times the rate for which the last official figures were reported, in 1994.
[edit] Conservation
Some people have calculated that it may even pay to save the forest. They said that one hectare of Amazonian forest in Peru is worth about US $ 6280, if it is used to harvest fruits, latex and timber (wood). If all the wood is cut down for timber, it has a value of about US $ 1000. Obviously, this can only be done once; it is not sustainable. When the forest has been cleared, the hectar of land can be used as a pasture, and is worth about US $ 148. Not all people agree on the study; some have questioned the assumptions behind it.
The Força Aérea Brasileira has been using EMBRAER R-99 surveillance aircraft to monitor the forest. This was done as part of the SIVAM program. At a conference in July 2004, scientists warned that the rainforest will no longer be able to absorb the millions of tons of greenhouse gases annually, as it usually does, because of the increased speed of rainforest destruction.
9,169 square miles of rain forest were cut down in 2003 alone. In Brazil alone, European colonists have destroyed more than 90 indigenous tribes since the 1900's. With them have gone centuries of knowledge of the medicinal value of rainforest species. As their homelands continue to be destroyed by deforestation, rainforest peoples are also disappearing.
[edit] See also
[edit] Notes
1. ^ Turner, I.M. 2001. The ecology of trees in the tropical rain forest. Cambridge University Press, Cambridge. ISBN 0521801834
2. ^ Melillo, J.M., A.D. McGuire, D.W. Kicklighter, B. Moore III, C.J. Vörösmarty and A.L. Schloss. 1993. Global climate change and terrestrial net primary production. Nature 363:234–240.
3. ^ Tian, H., J.M. Melillo, D.W. Kicklighter, A.D. McGuire, J. Helfrich III, B. Moore III and C.J. Vörösmarty. 2000. Climatic and biotic controls on annual carbon storage in Amazonian ecosystems. Global Ecology and Biogeography 9:315–335.
[edit] External links
- Amazon conservation
- Save the Amazon rainforest
- Amazon burning
- Sustainable Development and Biodiversity in the Amazon Rainforest
- More info on the Amazon Rainforest
[edit] References
- Peters, C.M. et al. "Valuation of an Amazonian Forest", Nature 339: 655-656, 1989.
- The Value of Tropical Forest to Local Communities: Complications, Caveats, and Cautions