| Tropical rain forest, in which neither
water nor low temperature is a limiting factor, is by far the
richest biome in terms of number of plant and animal species.
The trees are evergreen and characterized by medium-sized leathery
leaves. A poorly developed layer of herbs grows on the forest
floor, but there are many vines and epiphytes in the illuminated
zone far above the forest floor. Tropical soils are often acidic
and very poor in nutrients; such soils lose their fertility rapidly
when the forest is cleared. This biome now is estimated to be
about half the forested area of the earth, but sadly it is in
the process of being systematically destroyed by human activities. |
