The distribution of biodiversity is not uniform across the geographical regions of the earth. Certain regions of the world have very large number of species. These regions are called mega diversity zone. Twelve countries have been identified as mega diversity countries, which contain 60-70% of the world’s biodiversity. India is one of the mega diversity countries which contribute approximately 8% of the biodiversity.

Hot spots are the areas which are reservoirs of plant and animal life and are severely threatened. There are two factors that determine a hot spot:

i)                     Number of endemic species i.e. the species which are found nowhere else

ii)                   Degree of threat which is measured in terms of habitat loss.

All over the world 25 areas have been identified as hot spots out of which 4 are in India i.e. Himalayas, Western Ghats, North East India and Andaman and Nicobar Islands.