Hyla granosa, Tiputini Biodiversity Station, Rio Tiputini, Ecuador.
Bolitoglossa sp., Tiputini Biodiversity Station, Rio Tiputini, Ecuador.
The Amazon (from Wikipedia)
The Amazon River (occasionally River Amazon; Spanish: Río Amazonas, Portuguese: Rio Amazonas) of South America is one of the two longest rivers on Earth, the other being the Nile in Africa. The Amazon has by far the greatest total flow of any river, carrying more than the Mississippi, Nile, and Yangtze rivers combined — so while it may not be the longest river, it is undoubtedly the largest. Its drainage area, called the Amazon Basin, is the largest of any river system.
The quantity of fresh water released to the Atlantic Ocean is enormous: up to 300,000 m³ per second in the rainy season. Indeed, the Amazon is responsible for a fifth of the total volume of fresh water entering the oceans worldwide. It is said that offshore of the mouth of the Amazon potable water can be drawn from the ocean while still out of sight of the coastline, and the salinity of the ocean is notably lower a hundred miles out to sea.
The main river (which is usually between one and six miles wide) is navigable for large ocean steamers to Manaus, 1,500 km (more than 900 miles) upriver from the mouth. Smaller ocean vessels of 3,000 tons and 5.5 m (18 ft) draft can reach as far as Iquitos, 3,600 km (2,250 miles) from the sea. Smaller riverboats can reach 780 km (486 mi) higher as far as Achual Point. Beyond that, small boats frequently ascend to the Pongo de Manseriche, just above Achual Point.
The Amazon drains an area of some 6,915,000km² (2,722,000 mile²), or some 40 percent of South America. It gathers its waters from 5 degrees north latitude to 20 degrees south latitude. Its most remote sources are found on the inter-Andean plateau, just a short distance from the Pacific Ocean; and, after a course of about 6,400 km (4,000 mi) through the interior of Peru and across Brazil, it enters the Atlantic Ocean at the equator.
The Amazon has changed its drainage several times, from westward in the early Cenozoic to its present eastward locomotion following the uplift of the Andes.
Source and upper reaches
The ultimate source of the Amazon has only recently been firmly established as a stream on a 5,597 metre (18,363 ft) peak called Nevado Mismi in the Peruvian Andes, roughly 160 km west of Lake Titicaca and 700 km S.E. of Lima. The mountain was first suggested as the source in 1971 but this was not confirmed until 2001. The waters from Nevado Mismi flow into the Río Apurímac which is a tributary of the Ucayali which later joins the Marañón to form the Amazon proper.
After the confluence of Río Apurímac and Ucayali, the river leaves Andean terrain and is instead surrounded by flood plain. From this point to the Marañón, some 1,600 km (1,000 mi), the forested banks are just out of water, and are inundated long before the river attains its maximum flood-line. The low river banks are interrupted by only a few hills, and the river enters the enormous Amazon Rainforest.
The Amazon Rainforest is a term widely used to describe the moist broadleaf forests of the Amazon Basin. It encompasses 7 million km2 (1.2 billion acres), with parts located within nine nations: Brazil (with 60% of the rainforest), Colombia, Peru, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. This forest represents over half of the planet's remaining rainforests. States or departments in four nations bear the name Amazonas for the Amazon. Amazonian rainforests comprise the largest and most species rich tract of tropical rainforest that exists.
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. 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.)
More than one fifth of the Amazon Rainforest has already been destroyed, and the forest which remains is threatened. Not only are environmentalists concerned about the loss of biodiversity which will result from the forest's destruction, they are also concerned about the release of the carbon contained within the trees, which increases global warming.
Amazonian evergreen forests account for about 10% of the world's terrestrial primary productivity and 10% of the carbon stores in ecosystems  — on the order of 1.1 x 1011 metric tonnes of carbon . Amazonian forests are estimated to have accumulated 0.62 ± 0.37 tonnes of carbon per hectare per year between 1975 and 1996 . Fires related to Amazonian deforestation have made Brazil one of the top greenhouse gas producers. Brazil produces about 300 million metric tonnes of carbon dioxide a year; 200 million of these are come from logging and burning in the Amazon (pdf file).
In 1996, the Amazon was reported to have shown 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.
Some environmentalists commonly stress the fact that there is not only a biological incentive to protecting the rain forest, but also an economic one. One hectare in the Peruvian Amazon has been calculated to have a value of $6820 if intact forest is sustainably harvested for fruits, latex, and timber; $1000 if clear-cut for commercial timber (not sustainably harvested); or $148 if used as cattle pasture. The assumptions of this study have been widely challenged however.
The Força Aérea Brasileira has been using EMBRAER R-99 surveillance aircraft, as part of the SIVAM program, to monitor the forest. 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 pace 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 accumulated knowledge of the medicinal value of rainforest species. As their homelands continue to be destroyed by deforestation, rainforest peoples are also disappearing.
Tiputini Biodiversity Station, Rio Tiputini, Ecuador.
last updated: March 2006'
One of the many small streams in the lowland rainforest of the Ecuadorian Amazon, Tiputini Biodiversity Station, Rio Tiputini, Ecuador.
Glass-wing butterfly, Tiputini Biodiversity Station, Rio Tiputini, Ecuador.
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