South America and Central America (with the exception of southern Chile) together with small parts of the southern USA form the neotropical flora kingdom (Neotropis). 40% of all tropical plant species have their origin here. In terms of development history, South America has many peculiarities (endemics) because it has been separated from the rest of the land masses of the southern hemisphere since the collapse of Gondwana and the Central American land bridge was also frequently interrupted in the geological past. The most distinctive Neotropical families are the bromeliads (around 2,000 species) and the cacti, which comprise around 1,500 species. Because of the enormous north-south extent, which includes almost all climatic zones, and the pronounced vertical extension (Andes), a number of flora regions are distinguished.
According to countryaah, the core of South America is formed by the Amazon basin, the largest contiguous rainforest area on earth (Hyläa). This flat or slightly undulating landscape has only a slight gradient. Due to the changing water level of the Amazon and its tributaries, there is a seasonally differently large flood area with different forms of rainforests. The forests with the highest number of species are those whose soil lies outside the flood zone (terra firme). The adjacent floodplain forests (Igapó forests) have fewer species and are characterized by lower tree growth. They are regularly influenced by floods (water level difference up to 15 m) and are often under water for months. The even more humid areas are occupied by flood plains (Várzea), the deepest parts of which form shallow lakes of often large dimensions, which are fed by rainwater running off from higher areas. The higher Várzea locations have sparse trees, the lower grass growth and the lakes rich floating leaf flora. The rivers are from Accompanied by gallery forests. The rainforests are rich in species, including many well-known crops such as: B. Para rubber tree and cocoa tree.
South of the Amazon basin is the southern Brazilian flora region. It is characterized by a damp climate and great floristic variability. The most noticeable formations are forests of changeable moisture in the area of the east coast, savannas (Campos cerrados) and thorn bush (Caatinga). Another larger savannah area lies north of the Amazon basin (Llanos).
Between tropical Brazil and Patagonia, east of the Andes, there are wide, species-poor grasslands (pampas) in a warm, temperate climate), which turn further south into semi-deserts. In the equatorial part of the Andes, cloud forests dominate at 2,000–3,000 m above sea level, on the eastern flanks (uphill rain) up to almost 4,000 m above sea level, which are typical of tree ferns and tropical epiphytes. Above the tree line, grasslands (páramo) predominate, in which crested trees from the Espeletia genus are the dominant feature of the landscape. Further south (Peru, Bolivia, northern Chile, northern Argentina) the inner Andean highlands (Puna) show increasing semi-desert character to the south with frost-hard clump grasses, hard cushion and rosette plants. The western slopes of the Andes are dry and desert-like in these latitudes due to cold coastal currents (Atacama), whereas the rain-drenched eastern slopes are covered by forest. From about 30 ° south latitude, with better rainfall, thorn bush and hard deciduous trees appear, then evergreen forests with Nothofagus (pseudo beech), which extend as far as Patagonia. The main distribution area of the araucarias lies between the 37th and 40th parallel degrees of southern latitude, about 800–1,500 m above sea level.
The wildlife of South America is part of the Neotropical Region Neotropical. The isolation of South America from the other continents as a result of continental drift and because of the disruption of land connections with North America (until the end of the Tertiary) resulted in the development of a large number of endemic animal groups. In addition, the mosaic-like diversity of habitats corresponds to a diversity of animal species that is nowhere else on earth. However, the animal world, especially in the tropical rainforests of the Amazon region, is still largely unexplored (less than a tenth of the insect species that live in the treetops are known).
In terms of mammal fauna, the marsupials with 87 species that are otherwise only found in the Australian region stand out: opossums (with the exception of opossums, which also immigrated to North America) and opossum mice are only found in South America. Endemic are also sloths, anteaters, armadillos, tree prickles, guinea pigs, capybaras, pakaranas, agoutis, chinchillas, nutria, comb rats, stingrats, peccaries, tapirs (with the exception of the black-backed tapirs in Southeast Asia), guanaco, vicuna, large-nosed monkeys of the 140 bat species. The ocelot, jaguar and giant otter populations are endangered by fur hunters. The spectacled bear, which lives in the central regions of the Andes, is also threatened. Two types of river dolphins and two types of manatees live in the rivers of South America.
With around half of all known species, the bird world in South America has such an unusually high biodiversity that this area has also been referred to as the »bird continent«. More than 450 species have been counted in a single Amazon valley alone. Endemic are rheas, warbirds, hokko chickens, condors, macaws, many hummingbirds, glossy birds, lazy birds, toucans, potter birds, tyrants and ornamental birds.
Among the reptiles, snake-necked turtles, iguanas, coral snakes, lance snakes, giant snakes and caimans predominate. Among the amphibians, tree and stump foot frogs predominate. Fish and their parasites are related to African and Australian species and are v. a. represented in the Amazon with great biodiversity; z. B. Pirayas, hatchet-bellied fish, bone-tongues (with arapaima) and the electric trembling and knife eels. Also colibuses, mussel crabs, millipedes, stone flies and others. have family ties over the former South Pacific land bridge. The butterfly fauna is the richest on earth with at least 10,000 species.