All types of canopy of tropical and subtropical forests may create specific micro-site conditions below their crown, which act as a candidate for those species trying to regenerate underneath. According to the level of permeability or impermeability, each type of umbrella can partially determine the structure and composition of the plant community under the projection of the crown. Therefore, the current and future forest plant community biodiversity can be partially determined by the current structure of the canopy tree species community (filter effect).

The canopy system characteristic of tropical rain forests further increases diversity by creating new niches in the form of new sources of food, new shelters, new hiding places, and new areas for interaction with other species. In fact, it is estimated that 70-90 percent of life in the rain forest is found in the trees. One of the best examples of a canopy niche which multiplies diversity are the epiphytes, many of which form tiny ecosystems of their own. The tank bromeliads of New World forests can hold over eight liters (two gallons) of water in catchments formed in their stiff, upturned leaves. These pools of water serve as nurseries for frog tadpoles and insect larvae specifically adapted to life in this tiny obscure niche, and provide water for millions of other canopy dwellers. Over 28,000 epiphyte species are known to science, although many more have never been catalogued.