ABSTRACT
On the basis of the ecosystems, India has been divided into 10 biogeographic zones and 26 biotic provinces. Physically, the country is divided into four relatively well-defined regions: the Himalayan Mountains; the Gangetic Plains; the southern (Deccan) Plateau; and the islands of Lakshadweep, Andaman and Nicobar. With over 50,200 plant species, India represents over 12% of the world's known floral diversity. Insect diversity in India is characterized by a high level of endemism. The diversity of insects is greater in the northeastern states, the Western Ghats and the Andaman and Nicobar Islands, and these areas also have a high level of endemism. The Indian subcontinent has 2123 species and subspecies under 78 families and 20 orders thus representing 13.66 % of the world avian diversity. The recent estimate of aves, based on the discovery as well as the new records to India, is 1302 species.
