The number of species of plants and animals that are present in a region constitutes its species
diversity. This diversity is seen both in natural ecosystems and in agricultural ecosystems.
Some areas are more rich in species than others. Natural undisturbed tropical forests have a
much greater species richness than plantations developed by the Forest Department for timber
Biodiversity 83 production. A natural forest ecosystem provides a large number of non-wood products that local people depend on such as fruit, fuel wood, fodder, fiber, gum, resin and medicines.