Amazon Basin

node · earth · Northern South America

The drainage basin of the Amazon River and the largest continuous tropical forest on Earth, conventionally given as around 6.9 million square kilometres of catchment across eight sovereign states - Brazil, Peru, Colombia, Bolivia, Ecuador, Venezuela, Guyana and Suriname - plus French Guiana. Brazil holds roughly six-tenths of it and Peru roughly an eighth. Its scale is not the interesting fact about it; its self-sufficiency is. Rain arriving from the tropical Atlantic would exhaust itself within a few hundred kilometres of the coast if the land simply shed it to the sea. Instead the forest returns most of what lands on it to the atmosphere through transpiration, and the easterly trade winds carry that returned water further inland to fall again. The basin is therefore not a passive recipient of rainfall but a participant in producing it. Its tree flora is estimated at roughly sixteen thousand species and some 390 billion individual trees, of which a very small number of hyperdominant species account for about half of all stems.