Lowlands receive very little rain fall, and develop thorn forests. Nearer the equator regions have distinct wet and dry seasons and tropical deciduous forests occur. Trees releaf following heavy rains. Near the equator, where rainfall is abundant ,and the dry season lasts less than a few months is tropical rain forest. Contain more plant and animal species than any other community.
Competition is strong for light, soil is poor due to the rapid recycling of nutrients.
Animals are mostly tree dwellers. Soil is generally porous with a thin humus layer. Frequent fires inhibit invasion of trees. Hot deserts occur in S.W. USA, W. South America, North Africa, Middle East, Central Australia. Reptiles and seed eaters are common.