11.1.3 Magnitude of biodiversity

Biodiversity is often quantified as the number of species in a region at a given time. The current estimate of different species on earth is around - million. However, we really don’t know the exact magnitude of our natural wealth. This is called the ‘The Taxonomic impediment’.

So far about . million species of microorganisms, animals and plants have been Fig. .1a Species biodiversity described. Each year about - thousand new species are identified and published worldwide, of which % are invertebrates.

The number of undescribed species is undoubtedly much higher. India is very rich in terms of biological diversity due to its unique bio-geographical location, diversified climatic conditions and enormous eco-diversity and geo-diversity. According to world biogeographic classification, India represents two of the major realms (The Palearctic and Indo-Malayan) and three biomes (Tropical humid forests, Tropical Dry/