Biogeographic classification of India
Biogeography is the study of the distribution of species (biology), organisms, and ecosystems in geographic space and through geological time.
[2] India is also home to four biodiversity hotspots—Andaman & Nicobar Islands, Eastern Himalaya, Indo-Burma region, and the Western Ghats.
The Hindu Kush, Karakoram, and Himalaya are a major biogeographic boundary between the subtropical and tropical flora and fauna of the Indian subcontinent and the temperate-climate Palearctic realm.
Based on Olson et al. (2001),[9] the Worldwide Fund for Nature divided the land area of world into 14 terrestrial biomes or habitat types, based on vegetation,[Note 1] which are further subdivided into a total of 867 terrestrial ecoregions,[Note 2] which are exemplars of the concerned biome or habitat type.
[9] Only two terrestrial ecoregions from India – the Western Ghats and the Eastern Himalayas – figure in the Global 200 priority list of the WWF.
The forest type maps were prepared on 1;50,000 scale according to the Champion & Seth classification (1968) of the country and included States and UTs and districts.
[2][13] The Trans-Himalayan region with its sparse vegetation has the richest wild sheep and goat community in the world.
The snow leopard, black and brown bears, wolf, marmots, marbled cat, ibex, and kiang is found here, as are the migratory Black-necked Cranes.
The 2,400 kilometres (1,500 mi) long Himalayan mountain arc have a unique biodiversity owing to their high altitude, steep gradient and rich temperate flora;[16] biogeographically, they form part of the Palearctic realm.
Important animals living in the Himalayan ranges include wild sheep, mountain goats, ibex, musk deer and serow.
The larger is the Thar or Great Indian Desert, adjoining Pakistan and which comprises Rajasthan and parts of Punjab and Haryana.
Camels, gazelles, foxes, spiny-tailed lizards and snakes are found in hot and arid parts of the desert.
Other mammals found in the Rann include the Indian wolf, desert fox, chinkara, nilgai, blackbuck and others.
This region is characterised by discontinuous vegetation cover with open areas of bare soil and soil-water deficit throughout the year.
[14][15] The mountains along the west coast of peninsular India are the Western Ghats, which constitute one of the unique biological regions of the world.
The Western Ghats extend from the southern tip of the peninsula (8°N) northwards about 1600 km to the mouth of the river Tapi (21°N).
The mountains rise to average altitudes between 900 and 1500 m above sea level, intercepting monsoon winds from the southwest and creating a rain shadow in the region to their East.
The varied climate and diverse topography create a wide array of habitats that support unique sets of plant and animal species.
Rice cultivation in the fertile valley proceeded gardens of early commercial crops like areca nut and pepper.
The original vegetation of the ill-drained valley bottoms with sluggish streams in elevations below 100m would be often a special formation, the Myristica swamp.
The Western Ghats are well known for harboring 14 endemic species of caecilians (i.e., legless amphibians) out of 15 recorded from the region so far.
The Deccan plateau includes the region lying south of the Satpura range.it extends up to the southern tip of peninsular India.
The aggradational Great Plains cover about 72.4mha area with the Ganga and the Brahmaputra forming the main drainage axes in the major portion.
The east coast plains, in contrast are broader due to depositional activities of the east-flowing rivers owing to the change in their base levels.
Larger parts of the coastal plains are covered by fertile soils on which different crops are grown.
The main states of coastal areas are- Gujarat, Maharashtra, Goa, Karnataka, Kerala, west Bengal, Odisha, Andhra Pradesh, Tamil Nadu and Puducherry.
[22] This concept was developed by the British environmental expert Norman Myers in 1998 and subsequent years, and finalised in a paper published in Nature in 2000.
[3] India is home to four biodiversity hotspots—Andaman & Nicobar Islands, Eastern Himalaya, Indo-Burma region, and the Western Ghats.
The region has extremely rich plat and faunal communities as well as a number of iconic endangered species.
This region centres upon the Western Ghats range of mountains that runs along the west coast, which accounts for less than 6% of the national land area, but contains a rich endemic assemblage of plants, reptiles and amphibians, that comprises more than 30% of all bird, fish, herpetofauna, mammal, and plant species found in the country, including endangered iconic species such as the Asian elephant (Elephas maximus) and tiger (Panthera tigris), besides others.
