Zoogeographical Region of India
India falls under the Oriental Zoogeographical Region of the World. This region includes the Indian Subcontinent, Southern China, Malaysia, Phillipines, and the islands of and around Indonesia.
The majority of the areas denoted under this region are Tropical Forests, with considerable dry and partially desert areas in the North-western region where highly specialised adaptions are seen in species.
Species overlap in these regions across various orders and families, yet the taxonomical difference between them is not very dissimilar.
Sub-regions of the Oriental Region :
- Indian : From the foot of the Himalayas, across the Western & Eastern Ghats till the southernmost tip upto Mysore.
- Indo-Ceylonese : Sri Lanka and Southern India
- Indo-Chinese : Burma, Thailand, Laos, Vietnam and parts of Southern China
- Indo-Malayan : Malayan Peninsula, islands of the Malay Archipelago and Indonesia.
India comprises of just 2.4% of the Earth’s landmass, and it hosts biodiversity which amounts to 8% of the Earth’s species known to man today. India is considered a mega-diverse nation. The reasons for this are the unique geographical features which shape the landscape.
The 10 Bio-geographic Regions of India are
1. Trans Himalayan region
This is the high-altitude rain-shadow area of the Himalayan Mountains which display cold and arid conditions. These are unique cold deserts comprising of bare hills and sparse alpine steppe vegetation.
2. Himalayan Zone
3. Desert Region
4. Semi- Arid Region
5. Gangetic Plains Zone
The waters largely of the river Ganga, Brahmaputra and their tributaries drain a massive part of North India ; from the Foothills of the Himalayas in the North, Eastward in West Bengal and right up till the Deccan Plateau at its southernmost.
This is the lifeline of India, the alluvial soil of these great rivers provides livelihood and is the food belt of the country. The plains, once gigantic grasslands, are utilised for agriculture.
The natural ecosystem comprises of Alluvial Grasslands, Tropical forests of Sal, Teak & Mixed Forests, Riverine Forests, Swamps and Wetlands. Mega-herbivores and large carnivores can survive here with the varied floral diversity and relative availability of water.
The North-eastern States east of West Bengal, have absolutely the most varied flora and fauna of India. This area represents the transition zone between the Indian, Indo-Malayan and Indo-Chinese bio-geographical regions and is also the meeting point of the Himalayan Mountains and Peninsular India. It is indeed a biodiversity hotspot. It has a high incidence of endemism, and is a unique geographical zone of the world. Due to limited development, large corridors of connected forest and ecosystems yet remain intact lending to it, the reputation of being the Last Wildlife Frontier of India.
The area is mainly comprised of Tropical Evergreen Forests, Rainforests, Bamboo Forests, Rhododendron Forests, Mixed Forests, Pine Forests, Grasslands, Floating Islands, Wetlands, and Eastern Himalayan foothills.
7. Deccan Plateau
8. Western Ghats
The oldest mountain range of India, the Western Ghats is a precious ecosystem and of prime importance to India. The highest incidence of endemism in birds, fish, reptiles, insects and amphibians and flora is seen here. The area covers 5% of India’s land mass, yet 27% of all bio-diversity is recorded here, with more discoveries to be made.
Endemism of the Western Ghats :
Over 2100 species of plants, 83 amphibian species, 82 reptile species, 22 bird species, 16 mammal species, 8 species of butterfly are endemic to the Western Ghats. The major forest types are Tropical Evergreen forests, Shola Grasslands, Deciduous Forests, Scrub Land and Montane forests.
9. Coastal Region
India’s coastline stretches over 5500 km. Peninsular India is flanked on the Western side by the Arabian Sea, and on the Eastern Side by the Bay of Bengal. In the South, it is met by the Indian Ocean.
These areas consist of Sandy Beaches, Mud Flats, Mangroves, Salt Pans, Backwaters, Coral Reefs, Lagoons and Pastures of Marine Angiosperm ; acting as a protector of life along the coast and all its inhabitants.
India’s largest nesting ground for Sea-Water turtles is found on the east coast at Gandhisagar Wildlife Sanctuary in Orissa where almost 6,00,000 Olive Ridley Turtles make the beaches their nesting grounds.
5 out of 7 Marine Turtles in the world are found in the Indian Coastline.
The Sundarbans in Kolkata are the largest Mangrove Forests in the World, over 4000 sq.km in size.
Almost 12% of the worlds Fish Species are found in these areas.
30% of India’s population live along the Indian coastline.
The islands of India constitute about 0.3% of the land mass of India. The Andaman & Nicobar Islands contribute a huge amount to India’s Biodiversity – almost 10%.
The habitats here are Tropical Evergreen Forest – 1 of 3 areas where such forests occur in India – Andaman Moist Deciduous Forests, Littoral Forests, Mangroves and sandy Beaches.
Endemism of the Andaman & Nicobar Islands :
- Of around 9100 species found here, 1032 are endemic : more than 11%
- The endemism of marine species here is almost 4 times than on land.
The non-endemic species reflect a mixture of taxa from the Indo-China, Indo-Malayan and mainland India. This is likely due to the fact that these islands represent submerged peaks which once was a hill range extending from Myanmar to Indonesia.