India-a Megadiversity Nation

     

 India is situatedat the tri- junction of three realms: Afrotropical, Indo-Malayan and Paleo - Arctic realms which makes it rich in biological diversity.It represents 10 Biogeography zones, 26 Biogeography provinces with  ecosystems like forest, wetland, desert,  costal and marine. Though India shares 2.4% of world's land area, but represents 11% flora and 6.5% fauna of the world.Out of 17 megabiodiverse nations India ranks 9th in terms of richness of  higher plant species.

     Approximately 65% of Indian  geographical area has been survayed and over 46,000 plant  species and 81,000 animal species has been recorded .To preserve this rich biodiversity it has been divided into10 biogeographic zones: 

(1) Trans Himalayas with 3 provinces :

(A) Ladakh Mountains

(B) Tibetan Plateau 

(C) Sikkim Himalayas 

(2) The Himalayas with 4 provinces:

(A) North West Himalayas 

(B) West Himalayas

(C) Central Himalayas

(D) East Himalayas 

(3) The Indian Desert with 2 provinces: 

(A) Thar 

(B) Kutch

(4) The Semi Arid with 2 provinces:

(A) Punjab Plains

(B) Gujrat Rajputana

(5) Weaster Ghats with 2 provinces:

(A) Malabar Plains

(B) Western Ghat Mountains

(6) The Deccan Peninsula with 5 provinces:

(A) Central Highlands

(B) Chottanagpur

(C) Eastern Highlands 

(D) Central Plateau 

(E) Deccan South

(7) The Gangetic Plains with 2 provinces : 

(A) Upper

(B) Lower

(7) The Coasts with 3 provinces:

(A) West

(B) East

(C) Lakshadweep 

(9) Northeast India with 2 provinces:

(A) Brahmaputra Valley 

(B) North East Hills

(10) Islands with 1 province:

(A) Andaman and Nicobar 

 Biodiversity Hotspots:

A region with high species richness and a high degree of endemism is termed as Biodiversity Hotspot . Norman Mayer coined   Biodiversity Hotspot in 1988. Conservation International (CI) has adopted Mayer's hotspots in1996 and declared two restrictions for a hotspots:

(1) It must contain at least 1500 species of vascular plants ( >0.5% of the world's total) ae endemics .

(2) It has to have lost at least 70% of its original habitat i.e., it must have 30% or less of its original natural vegetation.

    In 2011 , the Forest of East Australia is declared as the 35th biography hotspots.

Biodiversity Hotspots in India :

(1) The Himalayas: It holds 163 endangered species including the Wild Asian Water Buffalo, One- horned rhino;and 10000 plant species of which 3160 are endemics.

(2) Indo- Burma Regions:  It has 1300 different bird species , including the threatened White eared Night heron, the grey crowned Crocias and orange nacked Partriged along with the endemics fresh water turtle species. It is also a home to large antlered Muntjac, the grey shanked Douc, the Annamite Striped Rabbit, the L eaf Deer and the Saola.

(3) Western Ghats : It is home to 325 globally threatened flora and fauna among them 129 as vulnerable, 145 as endangered and 51 as critically endangered. Among them 229 plant species, 31 mammal species, 15 bird species, 43 amphibian species 5 reptile species and 1fish species.

(4) Sundaland : It comprises 25000 plant species, out of which 15000 are endemics. It covers Andaman and Nicobar Islands(India), Singapore, Thailand, Brunei and Indonesia .