Forest types of India and their distribution
Natural vegetation means plants that grow by themselves and have been left undisturbed by people for a long time. Rainfall and temperature decide the type.
1. Tropical evergreen and semi-evergreen forests
Rain over 200 cm and warm all year. Tall trees (up to 60 m) in layers, so thick that sunlight hardly reaches the ground. No fixed time for leaf fall, so they look green all year. Trees: rosewood, ebony, mahogany. Where: western slopes of the Western Ghats, the north-east hills, the Andaman and Nicobar Islands. Semi-evergreen forests grow in slightly less rainy parts of the same regions.
2. Tropical deciduous forests (the most widespread)
Also called monsoon forests. Trees shed leaves for 6–8 weeks in the dry season. Moist deciduous (100–200 cm rain): teak, sal, shisham, sandalwood; north-east foothills, Jharkhand, Odisha, Chhattisgarh, eastern slopes of the Western Ghats. Dry deciduous (70–100 cm): teak, tendu, bel; rainier parts of the peninsula and the plains of Uttar Pradesh and Bihar. Many are cleared for farming.
3. Tropical thorn forests
Rain under about 70 cm (the driest parts under 50 cm). Thorny bushes, cactus-like plants, acacia, babul, ber, khejri. Long roots and small or no leaves to save water. Where: Rajasthan, Kachchh, south-west Punjab, Haryana and dry interior parts of the Deccan.
4. Montane forests
On mountains, temperature falls with height, so forests change like going from the tropics to the poles. In the Himalayas: 1,000–2,000 m wet temperate broadleaf forests (oak, chestnut); 1,500–3,000 m conifers (pine, deodar, spruce, fir); above about 3,600 m alpine forests and meadows (bugyals or margs) used for summer grazing; then tundra-like mosses, lichens and snow. In the south: sholas in the Nilgiris, Anaimalai and Palani hills.
5. Littoral and swamp forests (mangroves)
Grow in wetlands, deltas and tidal coasts. Mangroves have stilt and breathing roots in salty water. Where: the Ganga–Brahmaputra delta (Sundarbans, home of the Royal Bengal tiger and sundari trees), the Mahanadi, Godavari and Krishna deltas, and the Andaman and Nicobar Islands. India has about 3% of the world's mangroves.
Forest and wildlife conservation
Why forests matter
Forests give wood, fuel, fruit, gum, medicine and jobs. They hold soil, keep rivers flowing, store carbon and give homes to animals. India is one of the world's 17 mega-diverse countries with about 8% of the world's species on only 2.4% of its land.
Why they are shrinking
Clearing for farms, dams, mines, roads and towns, over-grazing, forest fires and illegal hunting and trade.
What India does
- Forest policy: the National Forest Policy aims for one-third (33%) of the land under forest; today forest cover is about 22% (about 25% with tree cover outside forests).
- Social forestry: planting trees on public and waste land, road and canal sides; farm forestry — farmers grow trees on their own fields; urban forestry — parks and green belts in cities.
- Wildlife (Protection) Act, 1972: bans hunting and trade of protected animals and allows national parks and sanctuaries. India has over 100 national parks and over 550 wildlife sanctuaries.
- Special projects: Project Tiger (1973), Project Elephant (1992), Crocodile Breeding Project, and projects for the rhino, snow leopard and Great Indian Bustard.
- People's movements: Chipko, Appiko, and joint forest management where villagers protect forests and share their produce.
Biosphere reserves
A biosphere reserve is a large protected area of land or coast that saves the whole ecosystem — plants, animals and the way of life of local people — while allowing careful use. It follows UNESCO's Man and the Biosphere programme.
Three zones
- Core zone: the centre, fully protected. No human activity except research and monitoring.
- Buffer zone: around the core. Research, education, training and limited eco-tourism.
- Transition zone: the outer ring. Villages, farms and other activities, with people and managers working together.
Biosphere reserves in India
India has 18 biosphere reserves. The first was the Nilgiri (1986), shared by Tamil Nadu, Kerala and Karnataka. More than 12 of them are in UNESCO's world network, for example Nilgiri, Gulf of Mannar, Sundarbans, Nanda Devi, Nokrek, Pachmarhi, Similipal, Achanakmar-Amarkantak, Great Nicobar, Agasthyamala, Khangchendzonga and Panna. Others include Manas, Dibru-Saikhowa, Dehang-Debang, Kachchh, Seshachalam and Cold Desert.
Difference: a national park protects wildlife with no human use; a sanctuary allows some activities; a biosphere reserve protects a whole landscape with its people.
Key formulas and definitions
- Rain > 200 cm → tropical evergreen; 100–200 cm → moist deciduous; 70–100 cm → dry deciduous; < 70 cm → thorn and scrub
- Himalaya by height: 1,000–2,000 m oak/chestnut → 1,500–3,000 m pine/deodar → 3,600 m+ alpine meadows → snow
- Mangroves = littoral and swamp forests of deltas and tidal coasts (largest: Sundarbans)
- Target forest cover = 33% of land; present ≈ 22%
- Biosphere reserve = Core (protected) + Buffer (research, eco-tourism) + Transition (people live and work)
- India: 18 biosphere reserves; first = Nilgiri (1986)
Worked examples
1. A place gets 250 cm of rain and is warm all year. Which forest will grow there? Name one tree.
Rain over 200 cm and warm → tropical evergreen forest. Trees: rosewood, ebony or mahogany.
2. Why do teak trees in Madhya Pradesh shed their leaves in March–May?
These are dry months. Leaves lose water through tiny pores. By shedding leaves the tree saves water until the monsoon returns; so they are called deciduous or monsoon forests.
3. A trekker climbs from 1,200 m to 4,000 m in Uttarakhand. List the vegetation she will pass.
About 1,200–2,000 m: oak and chestnut (wet temperate). 2,000–3,000 m: pine, deodar, spruce, fir. Above about 3,600 m: alpine shrubs and meadows (bugyals). Near 4,000 m and above: mosses, lichens, then snow.
4. A state has 90,000 km² of land and 18,000 km² of forest. What percentage is forest, and how far is it from the 33% goal?
18,000 ÷ 90,000 × 100 = 20%. Goal 33% of 90,000 = 29,700 km². It needs 29,700 − 18,000 = 11,700 km² more forest (13 percentage points).
5. In a biosphere reserve, where would you place (a) a tiger research camp, (b) a nature walk trail, (c) a village school?
(a) Core zone (research only). (b) Buffer zone (limited eco-tourism). (c) Transition zone (people live and work).
6. Why are mangroves called the 'guards of the coast'?
Their dense stilt roots slow down waves and storm surges, hold mud so the coast does not wash away, and give breeding places for fish. After cyclones, villages behind mangroves suffer less damage.
Common mistakes
- Thinking evergreen forests never shed leaves. They do, but at different times for different trees, so the forest looks green all year.
- Saying evergreen forests are the most common in India. Tropical deciduous (monsoon) forests cover the largest area.
- Mixing up national park and biosphere reserve. A biosphere reserve protects a whole ecosystem including local people, with three zones.
- Believing the forest-cover target is 50%. The National Forest Policy target is 33% (one-third) of the land.