Plant growth is rapid and dense. About 85 percent of the country is covered by tropical humid forest. The dense green of the vegetation never changes, since the more than 6,000 species of plants flower and lose their leaves continuously throughout the year according to species. Tree growth is especially rapid; some trees tower as high as 60 m, and the trunks are thickly entwined with vines. There are about 300 species of trees. In the coastal regions, marine plants abound, and wide expanses are covered with tall papyrus grass.
Wildlife includes forest elephants, buffalo, various antelope and monkey species, sitatungas, leopards, three species of crocodiles, chimpanzees and gorillas, and several marine turtle species which nest along the coast. As of 2002, there were at least 190 species of mammals.