Biogeographic Regions / Zones of India

India is a megadiverse country. With only 2.4 per cent of the total land area of the world, the known biological diversity of India contributes 8 per cent to the known global biological diversity. In terms of Biogeography, India has been divided into 10 biogeographic zones as shown in the below table:

India has been divided into ten recognizable biogeographic zones as follows:

Trans-Himalayan Region

It constitutes 5.6 per cent of the total geographical area, includes the high altitude, cold and arid mountain areas of Ladakh, Jammu & Kashmir, North Sikkim, Lahaul and Spiti areas of Himachal Pradesh. This zone has sparse alpine steppe vegetation that harbours several endemic species and is a favourable habitat for the biggest populations of wild sheep and goat in the world and other rare fauna that includes Snow Leopard and the migratory Blacknecked Crane (Grus nigricollis).  The cold dry desert of this zone represents an extremely fragile ecosystem.

Himalayan Zone

It constitutes 6.4 per cent of the total geographical area includes some of the highest peaks in the world.  The Himalayan zone makes India one of the richest areas in terms of habitats and species.

The alpine and sub-alpine forests, grassy meadows and moist mixed deciduous forests provide diverse habitat for endangered species of bovids such as Bharal (Pseudois nayaur), Ibex (Capra ibex), Markhor (Capra falconeri), Himalayan Tahr (Hemitragus jemlabicus), and Takin (Budoreas taxicolor). Other rare and endangered species restricted to this zone include Hangul (Cervus eldi eldi) and Musk Deer (Moschus moschiferus) .

Indian Desert Zone

Indian Desert Zone, constituting 6.6 per cent of the total geographical area, includes the Thar and the Kutch deserts and has large expanses of grassland that supports several endangered species of mammals such as Wolf (Canis lupus), Caracal (Felis caracal), Desert Cat (Felis libyca) and birds of conservation interest viz., Houbara Bustard (Chamydotis undulate) and the Great Indian Bustard (Ardeotis nigriceps).

Semi Arid Region

Semi-arid Region, constituting 16.6 per cent of the total geographical area, is a transition zone between the desert and the dense forests of Western Ghats.

Peninsular India has two large regions, which are climatically semi-arid. This semi-arid region also has several artificial and natural lakes and marshy lands.

The dominant grass and palatable shrub layer in this zone supports the highest wildlife biomass. The cervid species of Sambar (Cervus unicolor) and Chital (Axis axis) are restricted to the better wooded hills and moister valley areas respectively. The Lion (Leo persica), an endangered carnivore species (restricted to a small area in Gujarat), Caracal (Felis caracal),Jackal (Canis aureus) and Wolf (Canis lupus) are some of the endangered species that are characteristic of this region.

Western Ghats

Constitutes 4.0 per cent of the total geographical area. It is one of the major tropical evergreen forest regions in India and represents one of the two biodiversity ‘hot spots’. Western Ghats are home to viable populations of most of the vertebrate species found in peninsular India, besides an endemic faunal element of its own.

Significant species endemic to this region include Nilgiri Langur (Presbytis jobni), Lion Tailed Macaque (Macaca silenus), Grizzled Giant Squirrel (Ratufa macroura), Malabar Civet (Viverricula megaspila), Nilgiri Tahr (Hemitragus bylocrius) and Malabar Grey Hornbill (Ocycerous griseus). The Travancore Tortoise (Indotestudo forstem) and Cane turtle (Heosemys silvatica) are two endangered taxa restricted to a small area in central Western Ghats.

Deccan Plateau

Deccan Plateu is India’s largest biogeographic region making 42 per cent of the total geographical area. It’s a semi-arid region that falls in the rain shadow area of the Western Ghats. This bio-geographic zone of peninsular India is by far the most extensive zone, covering India’s finest forests, particularly in the States of Madhya Pradesh, Maharashtra and Odisha.

Majority of the forests are deciduous in nature but there are regions of greater biological diversity in the hill ranges.  The zone comprising of deciduous forests, thorn forests and degraded scrubland support diverse wildlife species.

Species found in this region are Chital (Axis axis), Sambar (Cervus unicolor), Nilgai (Boselapbus tragocamelus) and Chousingha (Tetracerus quadricornis), Barking deer (Muntiacus muntjak) and Gaur (Antilope cervicapra), Elephant (Elephas maximus) in Bihar-Orissa and Karnataka-Tamil Nadu belts, Wild  Buffalo (Bubalus bubalis) in a small area at the junction of Orissa, Madhya Pradesh and Maharashtra and the hard ground Swamp Deer (Cervus duvauceli), now restricted to a single locality in Madhya Pradesh.

Gangetic Plain

Gangetoc plain constitutes around 10.8 per cent of the total geographical area. The Gangetic plain is topographically homogenous for hundreds of kilometers.  The characterstic fauna of this region include Rhino (Rhinoceros unicornis), Elephant (Elephas maximus), Buffalo (Bubalus bubalis), Swamp Deer (Cervus duvauceli), Hog-Deer (Axis porcinus) and Hispid Hare (Carprolagus bispidus).

North East Region

North East Region constitutes 5.2 per cent of the total geographical area. This region represents the transition zone between the Indian, Indo-Malayan and Indo-Chinese bio-geographical regions as well as being a meeting point of the Himalayan mountains and peninsular India. The North-East is thus the biogeographical ‘gateway’ for much of India’s  fauna and flora and also a biodiversity hotspot (Eastern Himalaya).  Many of the species contributing to this biological diversity are either restricted to the region itself, or to the smaller localized areas of the Khasi Hills.

Coastal Region

Coastal region constitutes 2.5 per cent of the total geographical area with sandy beaches, mangroves, mud flats, coral reefs and marine angiosperm pastures make them the wealth and health zones of India.  The coastline from Gujarat to Sunderbans is estimated to be 5,423 km long. Atotal of 25 islets constitute the Lakshadweep, which are of coral origin, and have a typical reef lagoon system, rich in biodiversity. However, the densely populated Lakshadweep islands virtually have no natural vegetation.

Andaman and Nicobar Islands

This constitutes 0.3 per cent of the total geographical area are one of the three tropical moist evergreen forests zones in India. The islands house an array of flora and fauna not found elsewhere. These islands are centres of high endemism and contain some of India’s finest evergreen forests and support a wide diversity of corals. In India, endemic island biodiversity is found only in the Andaman and Nicobar Islands. Some of the endemic fauna of Andaman & Nicobar islands include Narcondam hornbill, South Andaman krait etc.