They are found in Central America, in Southeast Asia, on the coast of Brazil, and in other locations. The upper canopy of trees is relatively open, and there are fewer vines in the middle strata than in equatorial rain forests. Monsoon rain forests occur at low altitudes at the climatic and latitudinal edges of equatorial rain forests. In monsoon rain forests, the trees are generally shorter than those of equatorial rain forests, and there is a marked dry season when many species become leafless. As a result, more light passes through the canopy, and a dense, rich undergrowth thrives.
Monsoon forests are especially widespread in southeast Asia and Indonesia.
Plant species are derived generally from more temperate plant groups. The trees are smaller, and diversity is reduced. Montane rain forests are especially abundant in Central Africa, Indonesia, and the Andes in South America. Soil, Plants, and Animals Tropical soils are generally poor because minerals are continuously leached from the upper layers by heavy rainfall. The vertical stratification of trees is a characteristic feature of rain forests.