Biogeographic Zones of India: All 10 Zones and Wildlife

The biogeographic classification of India is the map that explains why a snow leopard, a lion-tailed macaque and a one-horned rhinoceros all count as Indian wildlife. A biogeographic zone is a large region whose climate, landform, soil and evolutionary history have produced a distinct assemblage of plants and animals. In 1988 W. A. Rodgers and H. S. Panwar of the Wildlife Institute of India, Dehradun, divided the country into ten biogeographic zones in their report on planning a wildlife protected area network, and this ten-zone scheme is the one every examiner uses. The zones are further broken into smaller biotic provinces, the revised scheme counting twenty-six of them. Examiners like the topic because it reduces to clean one-mark pairs: a zone and its state, a zone and its signature animal, a zone and its share of the country.

Zone, realm and forest type: three different things

A biogeographic realm is a continental unit; India lies mainly in the Oriental realm, with the Trans-Himalayan belt belonging to the Palaearctic realm, which is why Ladakh has Tibetan rather than tropical fauna. A biogeographic zone is the national subdivision of Rodgers and Panwar. A forest type, by contrast, comes from the Champion and Seth classification of 1968, which sorts Indian forests into sixteen major groups such as tropical wet evergreen and subtropical pine. Confusing the three is the commonest mistake in this chapter: Champion and Seth classified forests, Rodgers and Panwar classified biogeography.

The ten biogeographic zones at a glance

Zone-by-zone points worth memorising

• The Trans-Himalaya is a cold desert: rainfall is very low because the ranges lie in the rain shadow of the Great Himalaya, and the vegetation is sparse alpine steppe. Its fauna is Tibetan, not Indian tropical.
• The Himalayan zone rises through subtropical pine, temperate oak and deodar, and alpine meadow. The Hangul or Kashmir stag survives only in Dachigam, and the red panda and musk deer belong to this zone.
• The Indian Desert zone has two provinces, the Thar sand desert and the salt wastes of Kachchh. Khejri is its characteristic tree, the Indian wild ass is confined to the Little Rann of Kachchh, and the Desert National Park near Jaisalmer protects the great Indian bustard.
• The Semi-Arid zone, the belt between the desert and the Deccan, carries thorn and dry deciduous forest. Gir, home of the Asiatic lion, lies in this zone and not in the desert zone, a favourite trap.
• The Western Ghats zone holds tropical wet evergreen forest and the high-altitude shola grassland mosaic, with the highest endemism in peninsular India.
• The Deccan Peninsula is the largest zone, covering about two-fifths of the country, and is the heartland of India tiger reserves in sal and teak forest.
• The Gangetic Plain is the most densely farmed zone, so little natural vegetation is left; its wildlife survives in Terai grassland and swamp pockets such as Dudhwa.
• North-East India, the meeting ground of Indian, Chinese and Malayan elements, is the wettest zone and holds the alluvial grasslands of Kaziranga.
• The Coasts zone is a thin strip, but it carries the mangroves, including the sundari tree of the Sundarbans, and the mass nesting beaches of the olive ridley turtle.
• The Islands zone is the smallest in area yet the richest in endemic species, with coral reefs, Narcondam hornbill and Nicobar megapode found nowhere else.

Why the classification is used

The scheme was not academic: it was drawn up to check whether every natural region of India had protected areas of its own. A representative network means a national park or sanctuary for each zone and province, so that cold desert, mangrove and shola are each conserved, instead of protecting only the showy tiger forests. The same framework supports the identification of biosphere reserves, which are declared to cover representative ecosystems; Nokrek in Meghalaya, for instance, represents the North-East zone. India, one of the seventeen megadiverse countries, has only about 2.4 per cent of the world land area yet a far larger share of its recorded species, and parts of four global biodiversity hotspots fall within it: the Himalaya, Indo-Burma, the Western Ghats and Sri Lanka, and Sundaland through the Nicobar group.

Exam point traps

Three pairs decide most questions. Deccan Peninsula is the largest zone and Islands the smallest. Trans-Himalaya is the cold desert while Indian Desert is the hot desert. Gir belongs to the Semi-Arid zone, Kachchh wild ass to the Desert zone, and Kaziranga to North-East India. Remember also that the Western Ghats zone includes the Malabar coastal plain, which is why it is not counted inside the Coasts zone.