Chapter 17 — 5.6 Natural Vegetation of India

Natural vegetation is the plant community that has grown in a region on its own, over a long period, without the interference of human beings, and has adapted itself to the climate, soil and relief of the place. It is called virgin vegetation when it has never been disturbed. It includes forests, grasslands, scrub and the tundra of high mountains. It is distinguished from cultivated plants such as rice, wheat and tea, which are sown and tended by people, and from planted forests such as the eucalyptus and teak plantations of the Forest Department, which are put in by people even though they are trees. Plants that are native to a region are called endemic or indigenous, and plants that have been brought from outside, such as the eucalyptus from Australia and the lantana from South America, are exotic.

India's vegetation is very rich. The country has about 47,000 species of plants, some 6 per cent of the world's total and the tenth largest number for any country, including about 15,000 flowering plants, of which 5,000 are endemic. It has 89,000 species of animals. The reason is the variety of the physical environment: the country stretches from the equatorial forests of the Nicobar islands to the cold desert of Ladakh and from the wettest place on earth to a desert, and every climate carries its own plant community.

Natural vegetation matters for many reasons. Forests moderate the climate by adding moisture to the air through transpiration and by reducing the extremes of temperature. They regulate the water cycle, holding rain in their litter and soil and releasing it slowly to springs and rivers, so that floods are smaller and rivers do not dry up. They bind the soil with their roots and shelter it with their canopy, preventing erosion and the silting of reservoirs. They absorb carbon dioxide and release oxygen. They are the home of wildlife and the storehouse of the genes from which new crops and medicines are bred. And they supply timber, fuel, fodder, bamboo, resin, gum, lac, honey, fruits and medicinal plants, on which the tribal population of central India and the north-east directly depends.

The climax vegetation of a region is the stable community that finally develops when the vegetation has been left undisturbed long enough to reach balance with the climate; in most of India this would be forest, and the grasslands and scrub of today are largely the result of clearing, burning and grazing.

The character of the vegetation at any place is decided by the interplay of climate, soil and relief. The most important single factor in India is rainfall, because temperature is high enough for plant growth almost everywhere and it is water that limits it. Where the annual rainfall exceeds 200 cm and there is no long dry season, trees can keep their leaves all year and the forest is evergreen. Where rainfall is between 100 and 200 cm with a dry season of several months, the trees shed their leaves to reduce transpiration in the dry months and the forest is deciduous. Where rainfall is 50 to 100 cm the forest is dry deciduous and open. Below 50 cm only thorny scrub and grass survive, with small leaves, thick bark, long roots and thorns to reduce loss of water. Below 25 cm the land is desert with scattered bushes. The rainfall map and the vegetation map of India therefore follow each other closely.

Temperature matters where it falls low enough to check growth, that is on the mountains and in the extreme north. Along with rainfall it determines the type of forest: the humid tropics give broad-leaved evergreens, the cool temperate hills give oak and chestnut and the cold zone gives conifers.

Altitude works through temperature, which falls by 6.5°C for every 1,000 m, so that climbing a mountain is like travelling towards the pole. In the Himalaya the forest changes from tropical at the foot to temperate in the middle and alpine near the snow line within 4,000 m of height. Relief also decides how much rain a slope receives, so the windward southern slopes of the Himalaya and the western slopes of the Ghats are wetter and more densely forested than the leeward sides.

Soil decides the vegetation locally: the sandy soil of the desert and the saline mud of the tidal coast each carry a special flora, mangroves growing only where the soil is waterlogged with salt water, and sal preferring the well-drained laterite and red soil while teak prefers the moister black and alluvial soils. Sunlight and the length of the growing season add smaller effects, and in the last two thousand years the actions of people, cutting, burning, grazing and cultivating, have changed the vegetation of most of India more than any natural factor.

Indian forests are classified in several ways. By administration the Forest Department divides them into reserved forests, about 53 per cent of the total, which are permanently protected for timber and where grazing and collection are forbidden without permission; protected forests, about 29 per cent, where local people may graze cattle and collect fuel under rules; and unclassed forests, about 18 per cent, which are unsurveyed and mostly in the north-east and belong to communities. By ownership most forests are state forests, with small areas of community and private forest.

The classification that geography uses is by climate and character, based on the work of the botanists Champion and Seth, who recognised sixteen types. The school course groups them into five major types: tropical evergreen and semi-evergreen forests, of the areas with more than 200 cm of rain; tropical deciduous or monsoon forests, of 70-200 cm, themselves divided into moist and dry deciduous; tropical dry or thorn forests and scrub, of below 70 cm; tidal, littoral or mangrove forests, of the deltas and coasts; and mountain or montane forests, of the Himalaya and the higher peninsular hills, which change with altitude from sub-tropical through temperate to alpine. Some books add the semi-desert and desert vegetation of Rajasthan as a sixth type and the alpine zone as a seventh.

The two largest types by area are the tropical deciduous forests, which make up about two-thirds of India's forest, and the tropical dry forests; the evergreen and mountain forests each cover a small fraction, and the mangroves less than one per cent. The deciduous forest is thus the typical forest of India, and sal and teak are its typical trees, as the banyan and peepul are its typical village trees.

In the examination the student is expected to write the five types with their rainfall conditions, distribution, characteristics and three or four trees each, to draw them on a map, and to explain why a particular forest grows where it does. The topics that follow take each type in turn.

Tropical evergreen forests, also called tropical rain forests, grow where the annual rainfall exceeds 200 cm, the mean annual temperature is above 22°C, humidity is above 70 per cent and the dry season is short or absent. Under these conditions plants can grow all year, and the trees have no common season for shedding their leaves; each tree sheds and renews its leaves at its own time, so the forest as a whole never looks bare and is always green. This is what evergreen means.

Such forests are found on the western slopes of the Western Ghats from Maharashtra through Karnataka to Kerala and the hills of Tamil Nadu; in the north-eastern states of Assam, Arunachal Pradesh, Meghalaya, Nagaland, Manipur, Mizoram and Tripura and the Terai of north Bengal; and in the Andaman and Nicobar islands. Along the wetter parts of Odisha and the Bengal Duars the forest is semi-evergreen, a mixture of evergreen and deciduous trees where rainfall is 150-200 cm.

Their characteristics are those of the rain forest everywhere. The trees are very tall, 45-60 m, with straight trunks and buttressed bases, and they grow so densely that the forest has several layers or storeys: an upper canopy of giant emergents, a closed middle canopy, an understorey of smaller trees and shrubs, and a dark floor of ferns and mosses where the sun does not reach. Climbing plants, lianas, hang from the trees and epiphytes such as orchids grow on their branches. There are hundreds of species in a single hectare, mixed together rather than in stands of one kind, so that the forest is heterogeneous; this, with the hardness of the wood and the difficulty of transport in the dense, wet, roadless country, makes commercial exploitation difficult and expensive.

The important trees are rosewood, mahogany, ebony, ironwood, cinchona, rubber, gurjan, chaplash, toon, bamboo and cane, with hollong in Assam and coconut and palms along the coast. Rosewood and ebony give the most valued furniture timber, cinchona bark gives quinine, and the tea and rubber plantations of Assam and Kerala have replaced parts of this forest. The forests are the home of the elephant, the one-horned rhinoceros of Kaziranga, the hoolock gibbon and the lion-tailed macaque.

Tropical deciduous forests are the forests of the monsoon climate and are therefore also called monsoon forests. They grow where the annual rainfall is between 70 and 200 cm and there is a dry season of several months. To save water during the dry months the trees shed their leaves together, usually from February to April, so that the forest stands bare in the hot season and turns green with the first rain. This common leaf-fall is what the word deciduous means. These are the most widespread forests of India, covering about two-thirds of the forested area, and they are the country's chief source of timber.

They are divided by rainfall. Moist deciduous forests grow where the rainfall is 100 to 200 cm: the eastern slopes of the Western Ghats, the north-eastern states, the foothills of the Himalaya from Uttarakhand to north Bengal, Jharkhand, Odisha, Chhattisgarh, eastern Madhya Pradesh and the western districts of West Bengal. Their trees are 30-40 m tall and the forest is fairly dense, with bamboo and grass in the openings. Dry deciduous forests grow where the rainfall is 70 to 100 cm: the rain-shadow plateau of the Deccan in Maharashtra, Karnataka, Telangana and Andhra Pradesh, the plains of Uttar Pradesh and Bihar, western Madhya Pradesh and the eastern parts of Rajasthan and Gujarat. They are more open, with shorter trees and stretches of grass, and grade into thorn forest as rainfall falls.

Unlike the evergreens, the deciduous forests are comparatively homogeneous: a few valuable species occur in nearly pure stands over large areas, and the forest is more open, drier and easier to work, so it is heavily exploited. The two great trees are sal (Shorea robusta), the tree of the wetter east from Uttarakhand through north Bengal to Jharkhand, Odisha, Chhattisgarh and the rarh of West Bengal, whose hard timber is used for railway sleepers, beams and doors; and teak (Tectona grandis), the tree of the drier west and south in Madhya Pradesh, Maharashtra, Karnataka, Kerala and Tamil Nadu, whose durable, termite-resistant wood is the best furniture and ship timber in India. Other trees are shisham, sandalwood of Karnataka and Tamil Nadu, mahua, arjun, khair, bamboo, mulberry, palas, semul, haldu, amla, tendu, whose leaves are used for bidi, and neem. The forests shelter the tiger, leopard, sambar, chital, gaur, sloth bear and elephant, and most of India's tiger reserves are in them: Corbett, Kanha, Bandhavgarh, Simlipal and Palamau.

Where the annual rainfall is below 70 cm, and especially below 50 cm, with a long dry season, high temperature and low humidity, the deciduous forest gives way to tropical thorn forest and scrub. This is the vegetation of western and central Rajasthan, the southern Punjab and Haryana, Kutch and north Gujarat, and the driest parts of the interior Deccan plateau in Maharashtra, Karnataka, Telangana and Andhra Pradesh, especially the rain-shadow belt behind the Western Ghats around Solapur, Bijapur and Anantapur.

The plants of these regions are xerophytes, adapted to drought. The trees are short, 6-10 m, with thick bark, small waxy or hairy leaves that reduce transpiration, sharp thorns that protect them from browsing animals, and very long roots that reach deep for water; the acacia sends its roots 30 m down. They stand widely apart, so that the sun reaches the ground and the forest is open scrub with grass and bare earth between the trees; the grass grows in the short rainy season and withers in the dry. The characteristic trees are the acacias, especially babul (kikar) and khejri, the sacred tree of Rajasthan whose pods feed cattle and whose leaves are lopped for fodder, ber, neem, khair, date palm, the wild khair and kanju, euphorbias and cactus, and the thorny shrubs of the desert.

In the true desert of the Thar, where rainfall is below 25 cm, the vegetation is sparser still: scattered thorny bushes, tufts of grass such as sewan, the dune-fixing phog and khimp shrubs, and after a shower a brief flush of annual herbs that seed and die within weeks. Sand dunes have little cover, and the old dunes are fixed by the roots of the bushes; where these are cut or grazed the dunes move again. The Central Arid Zone Research Institute at Jodhpur has planted shelter belts and pastures to check the spread of the desert, and the Indira Gandhi canal has turned strips of the desert green with irrigated crops and planted trees.

The thorn forests are of little value for timber but of great value locally: babul gives gum, tanning bark and fuel, khejri gives fodder, ber gives fruit, and the grasses feed the vast herds of cattle, sheep, goats and camels of Rajasthan. Overgrazing has reduced much of this forest to bare scrub, and the semi-desert is spreading eastward.

Along the coasts, in the deltas and the estuaries where the rivers meet the sea, the land is flooded twice a day by the tide and the soil is waterlogged with salt or brackish water. Here grows a special vegetation called tidal forest, littoral forest or mangrove forest. The mangroves are found in the deltas of the Ganga-Brahmaputra (the Sundarbans), the Mahanadi (Bhitarkanika), the Godavari, the Krishna and the Kaveri (Pichavaram), along the coasts of Gujarat in the Gulf of Kutch and Gulf of Khambhat, and in the Andaman and Nicobar islands. India has about 4,900 sq km of mangrove, about 3 per cent of the world's total, and the Sundarbans alone account for over 40 per cent of India's mangroves.

The Sundarbans, shared by India and Bangladesh, is the largest mangrove forest in the world, about 10,000 sq km, of which about 4,200 sq km of forest lie in the South and North 24 Parganas districts of West Bengal. It takes its name from the sundari tree (Heritiera fomes), whose hard, durable timber is used for boats, houses and furniture. It is a UNESCO World Heritage Site, a national park and a tiger reserve, and the home of the Royal Bengal tiger, the estuarine crocodile, the Gangetic dolphin, spotted deer, wild boar and the olive ridley turtle.

The mangrove plants are halophytes, adapted to salt and to soft, oxygen-poor mud. They have stilt roots or prop roots that arch out from the trunk to hold the tree in the shifting mud, pneumatophores or breathing roots that grow upward from the mud like pencils to take in air at low tide, thick leathery leaves that store water and excrete salt, and viviparous seeds that germinate on the parent tree and drop as seedlings ready to root in the mud. The trees are of moderate height, dense, and form an almost impenetrable tangle. The characteristic trees are sundari, gewa (the raw material of the Khulna newsprint mill), goran, keora, hental, garjan, bain, kankra, golpata (nipa palm, for thatch), rhizophora and avicennia, with coconut, palmyra, casuarina, screwpine and pandanus on the sandy beach ridges of the coast.

The mangroves are of great value. They protect the coast against cyclones and storm surges by breaking the waves, as the Sundarbans did in Aila and Amphan; they hold the delta mud against erosion; they are the nursery of the prawns, crabs and fish on which the coastal economy depends; they supply honey, wax, fuel, timber and thatch; and they store more carbon per hectare than any other forest. They are threatened by clearance for prawn farms and rice, by the reduction of fresh water from the Ganga, by pollution and by the rising sea, and the Sundarbans has been made a biosphere reserve for their protection.

In the mountains the vegetation changes with height as temperature falls, so that the Himalaya shows on one slope the succession of plant types that a traveller would meet in going from the tropics to the arctic. This altitudinal zonation is the special feature of mountain or montane forests. The zones are clearest in the eastern Himalaya, which is wetter and where each zone begins lower, and in the Darjeeling hills of West Bengal a student can see them all within a day's journey.

The tropical zone at the foot of the mountains, up to about 1,000 m, has the sal and moist deciduous forest of the Terai and Duars with bamboo, semul and simul, grading into semi-evergreen forest in the wetter east. The sub-tropical zone, from 1,000 to 2,000 m, has wet hill forest of oak, chestnut, magnolia, laurel and tree ferns in the east, and chir pine forest on the drier western slopes of Himachal and Uttarakhand; the tea gardens of Darjeeling occupy this zone. The temperate zone, from 2,000 to 3,000 m, has broad-leaved forest of oak, maple, chestnut, walnut, birch, elm and rhododendron and the valuable conifers deodar (the Himalayan cedar, the finest timber of the western Himalaya), blue pine, silver fir, spruce and hemlock; the forests of Kashmir, Shimla, Mussoorie and Darjeeling belong here. The sub-alpine zone, from 3,000 to 3,600 m, has stunted silver fir, juniper, birch and dense thickets of rhododendron. The alpine zone, from 3,600 m to the snow line at about 4,500-5,000 m, is above the tree line and has alpine meadows of grass and flowering herbs (the bugyals of Uttarakhand and the margs of Kashmir, such as Gulmarg and Sonamarg), with dwarf rhododendron, juniper, mosses and lichens; these pastures are grazed in summer by the sheep and goats of the Gujjars, Bakarwals and Bhotias, who move down in winter. Above the snow line there is no vegetation.

In Ladakh and the trans-Himalaya, in the rain shadow, the vegetation is cold desert with scattered willow and poplar along the streams and thorny shrubs on the slopes. In the peninsular hills, the Nilgiris, Anaimalai and Palni hills of the south above 1,500 m, the mountain forest is temperate, called shola, with rolling grassland between patches of evergreen forest, and has been planted with eucalyptus, wattle and cinchona. Similar temperate forest occupies the higher parts of the Western Ghats and the Satpura.

The mountain forests hold the soil of the steepest slopes in India and regulate the flow of the Himalayan rivers; their felling for timber, roads, dams and fuel is the cause of the landslides and floods of the hills, and it was to save them that the Chipko movement began in the villages of Uttarakhand.

The National Forest Policy of 1952, repeated in 1988, laid down that one-third of India's land, 33 per cent, should be under forest or tree cover, with 60 per cent in the hills and 20 per cent in the plains, because that is the proportion needed to maintain the climate, the soil and the water supply. The country is far from that target. According to the biennial India State of Forest Report of the Forest Survey of India at Dehradun, the forest cover, that is the land actually carrying tree canopy of more than 10 per cent density as seen by satellite, is about 7.1 lakh sq km or about 21.7 per cent of the area of the country; with tree cover outside forests added, the total is about 24.6 per cent. The recorded forest area, the land legally classed as forest whether or not it carries trees, is larger, about 23.6 per cent.

The forest cover is unevenly distributed. By area Madhya Pradesh has the largest forest, followed by Arunachal Pradesh, Chhattisgarh, Odisha and Maharashtra. By percentage of the state's area the small north-eastern states lead: Mizoram about 85 per cent, Arunachal Pradesh 79 per cent, Meghalaya, Manipur and Nagaland above 70 per cent, and Lakshadweep 90 per cent among the union territories; the plains states are at the bottom, Haryana with about 3.6 per cent, Punjab 3.7 per cent, Rajasthan 4.9 per cent, Uttar Pradesh 6 per cent and Bihar 8 per cent. West Bengal has about 16,800 sq km of forest cover, about 19 per cent of the state, most of it in the Darjeeling and Jalpaiguri hills and Duars, the Sundarbans and the western rarh districts.

The forest cover is divided by density into very dense forest (canopy above 70 per cent, about 3 per cent of India), moderately dense forest (40-70 per cent, about 9.3 per cent) and open forest (10-40 per cent, about 9.3 per cent), and much of what counts as forest is thus degraded open woodland. In recent decades the total cover has stabilised and grown a little, largely through plantations, but the dense natural forest has continued to shrink in the north-east and the central belt.

The reasons for the low cover are historical and continuing: the clearing of the plains for agriculture over two thousand years, the felling of the hill forests for railway sleepers and timber in the nineteenth century, the pressure of a population that has multiplied five times since 1900 on a fixed area of land, and the demands of fuel, fodder, industry and dams. The examination expects the student to know the target, the present figure and the leading and lagging states.

The importance of forests is usually described under two heads. The direct or productive uses are the goods that forests yield. Timber for buildings, furniture, railway sleepers, boats and packing comes from sal, teak, deodar, shisham, rosewood and sundari. Fuel wood is still the cooking fuel of a large part of rural India, and more wood is burnt than sawn. Bamboo is used for houses, scaffolding, baskets, mats and paper pulp, and softwoods of the Himalaya and eucalyptus plantations feed the paper mills. The minor forest products are many: lac from the insect on palas and kusum trees in Jharkhand and Bengal, resin and turpentine from chir pine, gum from acacia, tendu leaves for bidi in Madhya Pradesh and Odisha, honey and wax from the Sundarbans, sal seed oil, mahua flowers, tanning bark, cane, medicinal plants such as cinchona, sarpagandha, neem and amla, fruits and fodder. About 300 million people, including most of the tribal population, depend on the forest for part of their livelihood, and forest-based industries such as paper, matches, plywood, sports goods, furniture and lac employ millions more.

The indirect or protective uses are the services that forests give without being cut. They regulate the climate, adding moisture to the air and moderating temperature, and are believed to help the monsoon rain fall. They conserve water: the forest floor absorbs the rain and releases it slowly, so that springs flow through the dry season, the ground water is recharged and floods are reduced. They protect the soil from erosion by the cover of the canopy and the binding of the roots, and so protect the reservoirs from silting. They purify the air, absorbing carbon dioxide and dust and releasing oxygen, and a tree of moderate size gives the oxygen of several people. They check the spread of deserts by fixing dunes and breaking the wind. They are the habitat of wildlife and the reservoir of biodiversity, the genes of wild rice and wild relatives of crops that plant breeders need. They give recreation and tourism, from the tiger reserves to the hill stations. And they have a cultural and religious value: the sacred groves of the Khasi hills, Kerala and the Western Ghats have preserved patches of virgin forest for centuries.

Economists now speak of the ecosystem services of forests and try to value them; by any measure the protective value of an Indian forest is many times its timber value, which is why the Forest Policy of 1988 put conservation before revenue.

Deforestation is the permanent clearing of forest for other uses. India has lost most of its natural forest over the centuries, and the loss continues, chiefly in the north-east, the central tribal belt and the Himalaya. Its causes are these. Agricultural expansion is the oldest and the largest: the whole Ganga plain was once forest, and clearing for fields continues at the margins of the forest wherever population grows. Shifting cultivation (jhum) in the north-eastern hills clears and burns forest on steep slopes and, as the fallow period has fallen from twenty years to three or four, the forest no longer recovers. Commercial felling for timber, railway sleepers and paper, legal and illegal, has stripped the sal and teak forests and the deodar and chir of the hills. Fuel wood and fodder collection by a population of over a billion, most of whom still cook on wood, removes the young growth and the regeneration. Overgrazing by 500 million cattle, goats and sheep kills seedlings and compacts the soil. Mining for coal, iron ore, bauxite and limestone in Jharkhand, Odisha, Chhattisgarh and Goa, dams and reservoirs such as Tehri, Sardar Sarovar and Narmada Sagar, which drown large forests, roads, railways, industry and towns, and forest fires, most of them set by people, complete the list.

The consequences are grave. Soil erosion increases many times on bare slopes, and the eroded silt fills the reservoirs and raises the river beds. Floods become more frequent and more severe because the rain runs off instead of soaking in; the floods of the Brahmaputra and the Kosi and the flash floods of Uttarakhand in 2013 are linked to the felling of the hill forests. Droughts and the drying of springs follow, because the ground water is no longer recharged, and the water table falls. Landslides multiply on the deforested Himalayan slopes. Climate becomes more extreme, local rainfall may decline, and the carbon dioxide released by burning forests adds to global warming. Wildlife loses its habitat, and species such as the cheetah have disappeared from India while the tiger, the rhinoceros, the lion-tailed macaque and hundreds of plants are endangered; the loss of biodiversity is irreversible. The desert spreads: the Thar is advancing eastward at an estimated half a kilometre a year where the thorn forest and grass have gone. And the tribal and forest-dwelling people lose their livelihood, their food, their medicines and their culture.

Deforestation is thus not a local loss of trees but a chain of damage that runs from the hillside to the delta, and the case for forest conservation rests on this chain.

Forest conservation means the protection of existing forests, their wise use so that they regenerate, and the planting of new ones. India's measures fall under law and policy, planting programmes and people's movements.

The National Forest Policy of 1952 set the 33 per cent target; the revised policy of 1988 shifted the aim of forestry from revenue to environmental stability and the needs of local people, and put the protective role of forests first. The Forest Conservation Act of 1980 requires the permission of the central government before any forest land is diverted to another use, and has slowed the loss of forest to dams, mines and roads; every diversion must now be matched by compensatory afforestation on an equal area. The Wildlife Protection Act of 1972 created the network of national parks (about 106) and wildlife sanctuaries (about 570) and banned hunting; Project Tiger of 1973 set up the tiger reserves, beginning with Corbett and including Sundarbans and Buxa in West Bengal, and Project Elephant of 1992 protects the elephant corridors of the Duars and the south. Biosphere reserves such as the Sundarbans, Nilgiri and Nanda Devi protect whole ecosystems with their people. The Forest Rights Act of 2006 recognised the rights of tribal and forest-dwelling communities to the forest they have used for generations, on the principle that they are its best guardians.

Afforestation and planting programmes include social forestry, begun in 1976, which plants trees on village common land, roadsides, canal banks and railway land and in farmers' fields (farm forestry) to meet the demand for fuel, fodder and small timber outside the natural forest and so relieve the pressure on it; agro-forestry, the growing of trees with crops; the Van Mahotsav tree-planting festival held every July since 1950; and joint forest management, begun in Arabari in Paschim Medinipur, West Bengal, in 1972 by the forest officer A. K. Banerjee, under which villagers protect a degraded sal forest and receive a share of its produce; the Arabari success became national policy in 1990 and there are now over one lakh forest protection committees.

The people's movements are the third strand. The Chipko movement began in 1973 in the Alaknanda valley of Uttarakhand when villagers of Reni, led by Gaura Devi and inspired by Sunderlal Bahuguna and Chandi Prasad Bhatt, hugged the trees to stop contractors from felling them; it spread through the Himalaya, won a fifteen-year ban on felling above 1,000 m and inspired the Appiko movement of Karnataka in 1983. The Silent Valley agitation of Kerala saved a rain forest from a dam in 1983, and the Bishnois of Rajasthan have protected the khejri and the blackbuck for three centuries. Along with these go the control of shifting cultivation, the substitution of fuel wood by LPG and biogas, the prevention of forest fires, the eviction of encroachers and the education of the public.

The forests of India are the home of a wildlife as varied as the vegetation: about 89,000 species of animals including 1,200 species of birds, 400 of mammals and 2,500 of fishes, more than 6 per cent of the world's fauna. Each forest type has its animals. The evergreen forests of the north-east hold the elephant, the one-horned rhinoceros of Kaziranga and Jaldapara, the hoolock gibbon, the clouded leopard and the hornbill; those of the Western Ghats the lion-tailed macaque, the Nilgiri tahr, the Malabar giant squirrel and the king cobra. The deciduous forests of the peninsula are the country of the tiger, leopard, gaur, sloth bear, wild dog, sambar, chital, barking deer and the swamp deer of Kanha; the Asiatic lion survives only in the dry deciduous Gir forest of Gujarat. The thorn forests and grasslands have the blackbuck, chinkara, nilgai, wolf, desert fox and the great Indian bustard, one of the rarest birds in the world; the mangroves have the Royal Bengal tiger, the estuarine crocodile, the fishing cat and the olive ridley turtle of Odisha's beaches; and the Himalaya has the snow leopard, musk deer, red panda of Darjeeling and Sikkim, Himalayan tahr, bharal, black bear, monal pheasant and the yak of Ladakh.

Many of these are endangered. The cheetah became extinct in India in 1952; the tiger fell from an estimated 40,000 in 1900 to 1,827 in 1972, and after Project Tiger has risen to about 3,600; the rhinoceros fell to a few hundred and has recovered to about 4,000 in Assam and north Bengal; the lion to fewer than 700 in Gir; the great Indian bustard to about 150. The causes are the loss and fragmentation of habitat by deforestation, poaching for skins, ivory, horn and bone, the killing of animals that raid crops or livestock, the spread of roads and canals through corridors, the pollution of rivers and wetlands, and hunting for sport in the past.

Protection rests on the Wildlife Protection Act of 1972, which lists protected species and bans their hunting and trade; the network of protected areas, about 106 national parks, 570 sanctuaries, 18 biosphere reserves and 54 tiger reserves covering about 5 per cent of the country; Project Tiger, Project Elephant, the crocodile breeding and vulture breeding programmes; the ban on the trade in ivory, skins and rhino horn under the international CITES convention; and the involvement of local people through eco-development. In West Bengal the protected areas include the Sundarbans national park and tiger reserve, Jaldapara and Gorumara national parks for the rhinoceros, Buxa tiger reserve, Neora Valley and Singalila national parks in the Darjeeling hills for the red panda, and the elephant corridors of the Duars.

West Bengal is a small state, but because it runs from the snow of the Singalila ridge at 3,636 m to the tidal mud of the Bay of Bengal it carries four of India's five forest types. Forests cover about 16,800 sq km, about 19 per cent of the state, well below the national target, and they lie in three separate blocks: the northern hills and Duars, the western rarh, and the Sundarbans.

The Darjeeling Himalaya shows the full altitudinal series. The Terai at the foot of the hills, below 300 m, has tall sal forest with semul, khair and sissoo and tall grasses, the habitat of the rhinoceros at Jaldapara and Gorumara and of the elephant. The lower hills from 300 to 1,000 m have moist deciduous and semi-evergreen forest with sal, toon, champ and bamboo. From 1,000 to 2,000 m the sub-tropical wet hill forest of chestnut, oak, alder, magnolia, laurel and tree fern surrounds the tea gardens of Kurseong and Darjeeling. From 2,000 to 3,000 m the temperate forest of oak, maple, birch, hemlock and rhododendron with orchids covers the ridges around Darjeeling and Ghum. Above 3,000 m on the Singalila ridge and at Sandakphu and Phalut the rhododendron thickets and silver fir give way to alpine meadow, where the red panda and the Himalayan black bear live in Singalila National Park.

The Duars of Jalpaiguri and Alipurduar, with 300-400 cm of rain, have dense moist deciduous and semi-evergreen forest of sal, hollong, chaplash, champ, gamar, simul and bamboo, cut by rivers and elephant corridors and containing the Buxa tiger reserve, Gorumara and Jaldapara; this is the best-forested part of the state, with Alipurduar and Jalpaiguri districts over 40 per cent forest.

The Rarh region in the west, Purulia, Bankura, Birbhum, western Bardhaman, Jhargram and Paschim Medinipur, on the laterite and red soil with 120-140 cm of rain and a long dry season, has tropical dry deciduous forest dominated by sal, with mahua, palas, kusum, kendu (tendu), arjun, piyal and bamboo, largely degraded to coppice and scrub by centuries of cutting and grazing and now regrowing under joint forest management; the Arabari forest is here, and the elephant herds that cross from Jharkhand. The Ayodhya hills of Purulia and the Susunia hill of Bankura carry this forest.

The Ganga plain and delta of central Bengal, the most densely peopled land in India, has almost no natural forest left; its vegetation is the village trees, banyan, peepul, mango, jackfruit, tamarind, coconut, betel nut, date palm and bamboo groves, and the water plants of the bils and marshes. The Sundarbans of the South and North 24 Parganas has the mangrove forest of sundari, gewa, goran, keora, hental and golpata described above, about 4,200 sq km, the largest single forest in the state, and the coast of Purba Medinipur at Digha has casuarina, screwpine and coconut on its sand ridges.

The Madhyamik examination tests this chapter through short answers, explanatory answers and map-pointing, and the student should practise each form. The short-answer questions ask for the definition of natural vegetation, the meaning of evergreen and deciduous, the names of two trees of each forest type, the tree from which the Sundarbans takes its name, the percentage of forest cover in India or its target, the year and place of the Chipko movement, the state with the largest forest area or the highest percentage, and the difference between reserved and protected forests. The answer should be one or two exact sentences with the figure or the name.

The explanatory questions ask why the forests of the Western Ghats are evergreen while those of the Deccan are deciduous, why the mangroves have breathing roots, why the vegetation of the Himalaya changes with height, why deforestation causes floods, how social forestry differs from joint forest management, what the importance of forests is, or what the causes and effects of deforestation are. The answer should define, give the conditions or causes in order with figures, and illustrate with a named example; a diagram of the altitudinal zones or the mangrove tree adds marks.

The map-pointing questions regularly ask for: a region of tropical evergreen forest (the Western Ghats of Kerala, or Assam); a region of tropical deciduous forest (the Chhotanagpur plateau or central Madhya Pradesh); a region of thorn forest (western Rajasthan); a region of tidal or mangrove forest (the Sundarbans); a region of mountain or coniferous forest (Himachal Pradesh or Uttarakhand); the Sundarbans itself; the state with the highest percentage of forest (Mizoram); a national park such as Kaziranga, Corbett, Gir or Kanha; and, in West Bengal questions, the Duars, Singalila, Jaldapara, Buxa and the Ayodhya hills.

A useful way to revise is a table with the five forest types as rows and columns for rainfall, temperature, distribution, characteristics and trees; another is a sketch map of India with the five types shaded in colour, drawn from memory until it is right. The student should be able to write the five types from the wettest to the driest, name the tree that identifies each (rosewood, sal or teak, babul, sundari, deodar), and match each to its West Bengal example (the Duars, the rarh, Rajasthan has none, the Sundarbans, Darjeeling).