Heywood and Watson evaluated 17 lakhs 50 thousand species in this universe. However Primental et al estimated 5-15 million species in this universe and out of which 80%, are arthropod and microbes and only small percentage is identified.
In India 46,610 species of plants and 630820 species of animals are present. 166 species is used in agriculture and 89 species of animals are domestic.
Biodiversity is not distributed uniformly across the globe. Some habitats, particularly tropical forest among terrestrial system possess a greater number or density of species than others.
An important study that has attempted to use endemic species to identify areas of global conservations concern was that of Myers (1988, 1990). Focusing on tropical forests, Myers identified 18 regions or ‘hot spots’ that are characterized by high concentration of endemic species and are experiencing unusually rapid rates of habitat modification or loss. Together these 18 sites contain approximately 50,000 endemic plant species or 20% of the worlds recorded plant species, in only 746,400 sq. km or 0.5% of earth’s land surface.
(1) Alaska (USA), (2) Alps (Europe), (3) Amazon (Latin America), (4) Antarctica (South Pole), (5) Arctic (North Pole), (6) Britain sea shore (France), (7) Callieyel island (Philippines), (8) Caribbean island (South Prasant), (9) Hudson way (USA Canada), (10) Medagarkar island (Eastern Africa), (11) Victoria lake (Kenya), (12) Lord Harre island, (13) Maldives island (SE Asia), (14) Masai Mara (Kenya), (15) Mediterranean sea-sore (16) Ryne river (Switzerland), (17) Sachalis island (18) St. Helena island.
Hot spots in India:
India is divided into 25 Hot spots:
1. Himalaya (India / Nepal)
2. Andaman & Nicobar Island
3. North Eastern Himalaya
4. Western Ghats
5. Manas (Assam)
6. Gir Forest (Assam)
7. Chota Rann of Kutch (Gujarat)
8. Narayan Sarovar (Gujarat)
9. Renuka lake and wet regions (Haryana)
10. Sivalik Hills (Himanchal Pradesh)
11. Poyam kutti valley (Kerala)
12. Silent valley (Kerala)
13. Dull lake (J & K)
14. Loktak lake (Manipur)
15. Chilka lake (Orissa).
16. Bharatpur lake & west region (Rajasthan)
17. Sariksha lake (Rajasthan)
18. Thar desert (Rajasthan)
19. Kodai lake (Tamil Nadu)
20. Neelgiri lake (Tamil Nadu)
21. Utti lake (Tamil Nadu)
22. Pilani Hills (Tamil Nadu)
23. Pulkit Mineral Lake (Tamil Nadu)
24. Doon Ghati (Uttarakhand)
25. Sunderbans (West Bengal)