Amazon Rainforest

The largest tropical rainforest ecosystem on Earth, spanning the drainage basin of the Amazon River across Brazil and eight neighboring South American countries. It holds an estimated ten percent of all known species on the planet within roughly a third the land area of the contiguous United States, and its trees release enough water vapor through transpiration to generate a substantial share of the region's own rainfall, a self-sustaining moisture cycle scientists call flying rivers. Large-scale deforestation for agriculture and cattle ranching has reduced the forest's original extent by close to a fifth, and research suggests continued clearing risks pushing parts of the ecosystem past a tipping point into a drier, savanna-like state that would not readily reverse.