Most of the far northeast (north and east of Bangladesh), northern West Bengal, and the west coast from Cochin to somewhat north of Bombay get more than 80 inches (200 centimeters) of rainfall annually. This is usually enough to keep the soil moist throughout the year. The natural vegetation associated with these regions is an exceedingly varied, broadleaf, evergreen rain forest, typically tall and dense. Much of the rain forest, however, is in hilly regions that have been repeatedly burned over and cleared for slash-and-burn agriculture, a type of farming particularly associated with India's tribal population. As a result, the soil has become less fertile. Where the forest has grown again, it is generally lower and less open than the original vegetation.

Areas with from 40 to 80 inches (100 to 200 centimeters) of rainfall (enough to grow at least one crop of rice) include almost the whole northeastern peninsular region, the eastern Gangetic Plain, a narrow belt on the plains and hills just south of the Himalayas as far west as Kashmir, another belt just east of the crest of the Western Ghats, and most of the southeastern, or Coromandel, coast. In these areas, as average rainfall declines the forests become progressively shorter, less dense, and less varied.

In addition, as rainfall declines from 80 to 60 inches (200 to 150 centimeters) evergreens gradually give way to deciduous species, which in these regions lose their leaves during the cool, dry season. Where government protection from slash-and-burn agriculture has kept forests intact, they include good stands of teak, sal, and other excellent timber species.

Most of the rest of India averages from 20 to 40 inches (50 to 100 centimeters), enough to grow one crop of grain other than rice. The natural vegetation consists of low, open forests, intermixed with thorny shrubs and grasses. Little of the original vegetative cover remains.

A wide variety of distinctive vegetation types occurs as a result of special ecological conditions. Tall grass savannas, with scattered acacias, grow on the moist soils of the Terai, the fringe of plains bordering the northern mountains. Mangrove forests are found in the brackish deltas of the east coast, and many types of palms grow in sandy or salty soils. Often impenetrable stands of bamboo sprout up in fields formerly given over to slash-and-burn cultivation.

The alterations in India's vegetation over the centuries have brought about many changes in the animal life. Today the dominant forms are cattle, goats, buffalo, sheep, and, in the drier regions, camels. While cattle are essential to the nation's economy, there is a religious taboo against their slaughter.

In the forests and the high, rugged areas where wild species are still dominant, the array of animals remains rich. Among large mammals are the Indian elephant, still regularly rounded up and domesticated in several areas; the rhinoceros, living almost exclusively in game sanctuaries; over a dozen species of deer and antelope; and wild cattle, sheep, goats, and boars.