The region is home to about 2.5 million insect species, tens of thousands of plants, and some 2000 birds and mammals. To date, at least 40,000 plant species, 3,000 fish, 1,294 birds, 427 mammals, 427 amphibians, and 378 reptiles have been scientifically classified in the region . Scientists have described between 96,660 and 128,843 invertebrate species in Brazil alone. 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 90,790 tonnes 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 worldlive 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 catalogued.

Deforestation is the conversion of forested areas to non-forested areas. The main sources of deforestation in the Amazon are human settlement and development of the land. Between 1991 and 2000, the total area of forest lost in the Amazon rose from 415,000 to 587,000 km², an area twice the size of Portugal, with most of the lost forest becoming pasture for cattle. Amazonian colonization was ruled by cattle raising because ranching required little labor, generated decent profits, and awarded social status in the community. However the results of the farming lead to extensive deforestation