The region's rainforest is spread across the Amazon River Basin (approx. 6.7 million km2), a vast natural tropical area more than half of which is located in Brazil. The basin also covers parts of Bolivia, Peru, Colombia, Ecuador, Venezuela and Guyana.
A considerable number of the world's plants and animals live in the Amazon, most of which remain undiscovered by scientists. Amazon wildlife shares this huge space with some 30 million people, including more than 220 indigenous groups in the Brazilian Amazon, 40 in Peru and 10 in Ecuador. In Venezuela, some 17 indigenous languages are spoken in the Amazon part of the country. This number is dwarfed by the Bolivian and Colombian Amazon, where 33 and 52 indigenous languages respectively are in use.
The organic material and nutrients in a tropical rainforest are found in the vegetation itself, not in the soil. This eroded hillside along a river in Amazonia shows the infertile soil typical of tropical environments (pinkish-tan) topped by a very thin layer of fertile soil and forest detritus (brown):
The Amazon accounts for more than half of the world's rainforest. No other ecosystem on Earth is home to so many species nor exerts such control on the carbon cycle. For years the Amazon forest acted as a vast carbon sink that absorbed one fifth of global fossil fuel emissions. But in 2005 this process was reversed.
Between May 2000 and August 2006, Brazil lost nearly 150,000 square kilometers (58,000 square miles) of forest and since 1970, over 600,000 sq km (232,000 sq mi) of Amazon rainforest have been destroyed.Deforestation in the Amazon
- Amazon Eye is an environmental information system for the Amazon Basin providing easily browsable data and imagery on recent environmental change in Google Earthsource
Brazil's National Institute of Amazonian Research suggests that the felling is both drying up the entire forest and helping to cause the hurricanes that have been battering the United States and the Caribbean. The hot, wet Amazon normally evaporates vast amounts of water, which rise high into the air as if in an invisible chimney. This draws in the wet north-East trade winds, which have picked up moisture from the Atlantic. This in turn controls the temperature of the ocean; as the trade winds pick up the moisture, the warm water that is left gets saltier and sinks.
Deforestation disrupts the cycle by weakening the Amazonian evaporation which drives the whole process. One result is that the hot water in the Atlantic stays on the surface and fuels the hurricanes. Another is that less moisture arrives on the trade winds, intensifying drought in the forest. "We believe there is a vicious cycle" says Dr. Antonio Nobre.
So far about a fifth of the Amazonian rainforest has been razed completely. Another 22 per cent has been harmed by logging, allowing the sun to penetrate to the forest floor drying it out. And if you add these two figures together, the total is growing perilously close to 50 per cent, which computer models predict as the "tipping point" that marks the death of the Amazon.Dying Forest