The largest tropical rainforest on Earth, about 5.5 million square kilometres
Roughly 60% lies in Brazil, the rest across Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana
Geography · Physical geography
The Amazon rainforest
South America — nine countries, about 60% of it in Brazil
The largest tropical rainforest on Earth, some 5.5 million square kilometres draped over the basin of the world's greatest river. It holds perhaps a tenth of all known species, recycles its own rainfall through "flying rivers" of transpired moisture, and sits on soils so poor that the fertility is almost entirely in the living canopy — which is why clearance is so hard to undo.
How to spot them
- ▸The largest tropical rainforest in the world, spanning nine countries
- ▸Quiz clue: 'terra preta', 'flying rivers', 'várzea', 'Meeting of the Waters', 'Manaus'
- ▸Often called the lungs of the planet — a nickname ecologists dislike, because mature forest consumes nearly as much oxygen as it produces
- ▸Its rainfall is partly self-made: moisture transpired by the trees falls again further inland
Key facts
Called the lungs of the planet, though a mature forest's net oxygen contribution is close to zero
Respiration and decay consume nearly as much oxygen as photosynthesis releases; the real climate value is stored carbon
Its trees transpire 'flying rivers' of moisture that carry rainfall thousands of kilometres inland
A single large tree can release hundreds of litres of water vapour a day
Its soils are famously poor, except for the dark, charcoal-rich anthropogenic patches called terra preta
Made by pre-Columbian populations — evidence that the basin supported large settled societies
At Manaus the black Rio Negro runs beside the pale Solimões for kilometres without mixing
The Meeting of the Waters: different temperature, density and speed keep the two apart
Seasonal floods raise the water by over ten metres, creating the várzea and igapó flooded forests
River dolphins and fruit-eating fish feed among the tree crowns
Henry Walter Bates and Alfred Russel Wallace collected here together from 1848 (1848)
Bates described the mimicry that bears his name; Wallace lost most of his specimens when his ship burned on the voyage home
Quick-fire facts
- •It covers about 5.5 million km², within a drainage basin of some 7 million km²
- •Roughly 60% lies in Brazil, with Peru holding the next largest share
- •It is estimated to hold around 390 billion trees of some 16,000 species, and about 10% of all known species on Earth
- •Terra preta — dark, fertile, charcoal-enriched soil — is evidence of dense pre-Columbian settlement, not untouched wilderness
- •Deforestation has been tracked by satellite by Brazil's space agency INPE since 1988
- •The Central Amazon Conservation Complex was inscribed as a UNESCO World Heritage site in 2000 and extended in 2003
- •Common misconception: it is not 'the lungs of the planet' — old-growth forest is roughly oxygen-neutral; its importance is as a carbon store and a rainfall engine
- •Another misconception: its soils are not rich — most nutrients are locked up in the standing vegetation
Drill it — 8 cards
1 / 8new card
Sources
- UNESCO World Heritage Centre — Central Amazon Conservation Complex
- NASA Earth Observatory — World of Change: Amazon Deforestation
- Henry Walter Bates — The Naturalist on the River Amazons