<P> More than half of the world's species of plants and animals are found in the rainforest . Rainforests support a very broad array of fauna, including mammals, reptiles, birds and invertebrates . Mammals may include primates, felids and other families . Reptiles include snakes, turtles, chameleons and other families; while birds include such families as vangidae and Cuculidae . Dozens of families of invertebrates are found in rainforests . Fungi are also very common in rainforest areas as they can feed on the decomposing remains of plants and animals . </P> <Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (December 2008) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (December 2008) </Td> </Tr> <P> Despite the growth of vegetation in a tropical rainforest, soil quality is often quite poor . Rapid bacterial decay prevents the accumulation of humus . The concentration of iron and aluminium oxides by the laterization process gives the oxisols a bright red colour and sometimes produces mineral deposits such as bauxite . Most trees have roots near the surface, because there are insufficient nutrients below the surface; most of the trees' minerals come from the top layer of decomposing leaves and animals . On younger substrates, especially of volcanic origin, tropical soils may be quite fertile . If rainforest trees are cleared, rain can accumulate on the exposed soil surfaces, creating run - off and beginning a process of soil erosion . Eventually streams and rivers form and flooding becomes possible . </P>

How many rainforests are there in the world wikipedia