Species diversity

The number of species of plants and animals that are present in a regieon constitues Its species diversity.This diversity is seen both in natural ecosystems and in agricultural ecosystems.some areas are richer in species than others.For example,natural undisturbed tropical ecosystems.some areas are richer in species richness then monoculture plantations developed by the forest Department for timber production .A natural forest ecosysstem provides a large number of non-timber forest products(NTPF's)that local people depand on ,such as fruit ,fuelwood,fooder,fiber,gum ,resin and medicins.Timber plantations do not provide the large variety of goods that are essential for local consumption .In the long-term ,the economic sustainble returns from NTFPs is said to be greater than the returns from felling a forest for its timber.Thus ,the commercial value of a ntural forest ,with all its species richness is much greater than a plantation .Moderen intensive agricultual ecosystem have a relatively lower diversity of crops than treditional agro-pastoral farming systems,where multiple crops were planted.

At present ,conservation scientists have been able to identify and catagerize about 1.8 million species on Earth .However,this this is only a fraction of what really exists .Many new species are being identified especially in the flowering plants and insects.Areas that are exceptionally rich in speicies diversity are called especially'hotspots'of diversity ;India is among the world's 15 nations that are exceptionally rich in species diversity.