India as a Mega-diversity Nation & Biodiversity Hotspots

1. India — a mega-diverse country

• India is one of the 17 mega-diverse countries identified by Conservation International (with Brazil, Indonesia, Australia, China and others).
• With about 2.4% of the world's land area, India holds about 7–8% of recorded species — over 1 lakh animal and about 50,000 plant species (fungi and others included).
• Reasons: varied climate (tropical to alpine), physiography (Himalayas to coasts and islands), and its position where the Indo-Malayan, Afro-tropical and Palaearctic realms meet.
• India is also a centre of origin of crops (Vavilov) — rice, sugarcane, mango, citrus, banana, pepper and many legumes.

Biogeographic zones

India is divided into 10 biogeographic zones (Rodgers & Panwar): Trans-Himalaya, Himalaya, Desert, Semi-arid, Western Ghats, Deccan Peninsula, Gangetic Plain, North-East, Coasts, Islands.

Endemism

• Endemic species occur naturally nowhere else — high in the Western Ghats, North-East and Andaman & Nicobar Islands.
• Examples: Nilgiri tahr, lion-tailed macaque, Malabar civet, purple frog, Asiatic lion (wild only in Gir).

2. Biodiversity hotspots