Natural Vegetation and Wildlife

1. Factors Affecting Vegetation

Natural vegetation refers to a plant community that grows naturally without human aid. It is also called virgin vegetation. The character and extent of natural vegetation depends on three major sets of factors:

A. Relief

• Land/Altitude: Vegetation changes with altitude. The Himalayas show distinct vegetation zones from tropical at the foothills to tundra-like near the snowline. Plains and plateaus support different vegetation from mountain slopes.
• Slope: Steeper slopes have thinner soils and less moisture — forests here are sparser. Gentle slopes and valley floors support denser and taller forests.

B. Climate

• Temperature: Controls the type of vegetation. Tropical regions (high temperature year-round) support evergreen species; cooler zones support coniferous or deciduous species. Temperature falls with altitude, changing vegetation type.
• Rainfall/Precipitation: The single most important climatic factor. Areas receiving over 200 cm support dense evergreen forests; 70–200 cm supports deciduous forests; below 70 cm supports scrub and thorny vegetation.
• Photoperiod (sunlight hours): Trees grow faster in summer because of longer hours of sunlight. Sunlight also varies with latitude and altitude.
• Wind: Strong winds in coastal areas can stunt growth; winds also help in seed dispersal.

C. Soil

• Different soils support different types of vegetation. Sandy desert soils support cactus and xerophytes; deltaic and alluvial soils support mangroves; laterite soils (poor nutrients) support grasses and shrubs.
• Soil depth, texture, and water-holding capacity all influence the density and type of plants that can survive in a place.

2. Tropical Evergreen Forests

Also called Tropical Rainforests. These are the densest, most species-rich forests in India.

Conditions required

• Rainfall: more than 200 cm per year.
• Temperature: high throughout the year (warm and humid climate).
• No distinct dry season — trees do not shed leaves simultaneously, so the forest remains green all year — hence the name "evergreen".

Where they are found

• Western slopes of the Western Ghats (the windward side receiving heavy monsoon rainfall).
• Parts of the North-Eastern states — Assam, Meghalaya, Nagaland, Mizoram, Manipur, Tripura — and the foothills of the Himalayas.
• Andaman and Nicobar Islands.
• Parts of the Tamil Nadu coast and Lakshadweep.

Characteristics

• Forests are multi-layered with a very dense canopy; light hardly reaches the forest floor.
• Trees grow very tall (up to 60 m or more).
• Rich biodiversity — hundreds of species in a small area.
• Commercially less exploitable because the species are mixed and trees are difficult to extract selectively.

Important tree species

• Mahogany — highly valued hardwood; used in furniture.
• Ebony — very hard, dark wood used for piano keys, sculptures.
• Rosewood — used in furniture and musical instruments.
• Other species: rubber, cinchona, and several varieties of palms, orchids, and ferns.

Wildlife

Elephants, monkeys, lemur, deer, one-horned rhinoceros (Assam), many bird species, bats, sloth, and scorpions.

3. Tropical Deciduous Forests (Monsoon Forests)

These are the most widespread forests in India and are called Monsoon forests because they are strongly influenced by the monsoon climate. The word "deciduous" means trees shed their leaves in the dry season (usually 6–8 weeks) to conserve water.

Conditions required

• Rainfall: 70 cm to 200 cm annually.
• A distinct dry season during which trees shed their leaves.

Two sub-types

Important tree species

• Teak — the most commercially important tree in India; hard, durable wood used in furniture, railway sleepers, and ship-building.
• Sal — another important timber tree; found in Jharkhand, Odisha, Chhattisgarh.
• Peepal (Sacred Fig) — deciduous; sheds leaves in spring; culturally and religiously important.
• Neem — medicinal properties; leaves used as natural pesticide.
• Other species: Shisham, Sandalwood (South India), Bamboo, Arjuna, Mulberry, Kusum.

Wildlife

Lions, tigers, pigs, deer, and elephants are commonly found in these forests.

Commercial importance

Unlike evergreen forests, deciduous forests are more accessible and trees are more uniformly distributed, making commercial extraction easier. Teak and sal are extensively harvested.

4. Tropical Thorn Forests and Scrubs

These are found in areas where rainfall is scanty and the climate is dry or semi-arid.

Conditions required

• Rainfall: less than 70 cm annually.
• High temperature and low humidity.
• Prolonged dry seasons with very hot summers.

Where they are found

• The north-western parts of India — Rajasthan, Gujarat, Madhya Pradesh, Uttar Pradesh, Haryana, and Chhattisgarh.
• Parts of the semi-arid Deccan plateau.
• The Thar Desert and surrounding regions.

Characteristics and plant adaptations

• Trees are scattered and short with long roots to tap groundwater.
• Leaves are thick, small, waxy, or reduced to spines to minimise water loss — a xerophytic adaptation.
• Stems may be succulent (store water).
• Plants are often thorny to deter animals from eating them.

Important plant species

• Acacia — thorny shrub/tree; most common in arid zones.
• Cactus — succulent; stores water in thick stems; reduced leaves (spines).
• Euphorbias (spurges) — look like cactus; common in Deccan.
• Palms, Khejri (Prosopis cineraria) — sacred tree of Rajasthan; provides fodder and shade.

Wildlife

Rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses and camels are found here.

5. Montane Forests (Mountain Forests)

In mountainous areas, altitude replaces latitude as the key factor determining vegetation. As we go up a mountain, temperature falls and vegetation changes — this is called altitudinal zonation. The sequence on the Himalayas from low to high altitude is:

Zone 1: Tropical Wet Evergreen (below ~1,000 m)

• Found at the base of the Himalayas — Terai and Duars of West Bengal and Assam.
• Dense tropical vegetation; sal, ferns, and orchids dominate.

Zone 2: Subtropical Broadleaf (1,000–2,000 m)

• Oak and chestnut are common at this elevation. Chirpine (Pinus roxburghii) also appears.

Zone 3: Temperate / Coniferous (1,500–3,000 m)

• Dominated by coniferous (cone-bearing) trees with needle-shaped leaves adapted to snow.
• Key species: Oak, Rhododendron, Deodar (sacred cedar), Silver Fir, Spruce, Pine, Cedar.
• Deodar is highly valued for construction; rhododendrons provide vibrant colour in spring.
• These forests are also found in the Nilgiris and other Peninsular hill ranges (Anamalai, Cardamom hills) at corresponding altitudes.

Zone 4: Alpine (above 3,600 m)

• Above the treeline; scrubby junipers, birch (Bhojpatra) survive.
• The bark of Bhojpatra was used in ancient times for writing manuscripts.
• Cushion plants and flowering alpine herbs grow in summer; used by nomadic tribes for grazing.

Zone 5: Tundra Vegetation (near snowline)

• Only mosses and lichens survive very close to the snowline.

Southern mountain forests

• The Western Ghats hills have subtropical broadleaf hill forests with magnolias, laurels, cinchona, and eucalyptus.
• Grasslands called Sholas occur between patches of forest in the Nilgiris.

Wildlife of montane zones

Kashmir stag (hangul), spotted deer, wild sheep, Tibetan antelope (chiru), yak, snow leopard, red panda, squirrels, shaggy-horn wild ibex, and bear.

6. Mangrove Forests (Tidal Forests)

Mangrove forests are found where land meets the sea — in tidal mudflats, deltas, and coastal areas influenced by salt water.

Conditions required

• Saline/brackish water and tidal flooding.
• Warm tropical/sub-tropical temperatures.
• Soft, waterlogged, muddy soil where mud and silt gather.

Where they are found

• Sunderbans (West Bengal) — the largest mangrove forest in the world; a UNESCO World Heritage Site; located in the delta of the Ganga–Brahmaputra. Named after the Sundari tree.
• Andaman and Nicobar Islands.
• Deltas of the Mahanadi, Krishna, Godavari and Kaveri rivers.
• Coastal areas of Odisha, Andhra Pradesh, Tamil Nadu, Kerala, Maharashtra, Goa.

Unique adaptations

• Prop roots (stilt roots): Aerial roots that provide support in soft mud and allow the tree to stand in water.
• Pneumatophores (breathing roots): Roots that stick upward out of the mud to absorb oxygen from the air — necessary because waterlogged soil is oxygen-deficient.
• Vivipary: Seeds germinate while still on the parent tree — an adaptation to the unstable saline environment.
• Thick, waxy leaves to cope with high salinity.

Important species

• Sundari tree — gives the Sunderbans its name; provides hard, durable timber used for boat-building.
• Rhizophora, Avicennia, Sonneratia — common mangrove genera.
• Keora, agar, and palms also occur.

Wildlife

The Royal Bengal Tiger is the most famous animal of the Sunderbans. Also: turtles, crocodiles, gharials, and snakes.

Ecological importance

• Act as a natural shield against cyclones and sea storms — protect coastal communities.
• Prevent coastal erosion by holding mud with their roots.
• Nursery habitat for fish and other marine organisms.
• Important carbon sinks — help combat climate change.

7. Wildlife of India and Conservation Projects

India is one of the world's mega-biodiverse countries. It has about 8% of the world's total number of species, even though it covers only about 2.4% of the world's land area.

Key wildlife facts

• About 47,000 plant species and 90,000 animal species in India.
• About 2,000 species of birds (12% of the world's stock of birds).
• About 2,546 species of fish — nearly 12% of the world's fish species.
• India ranks among the top countries for endemic species of vertebrates.

Distribution of wildlife by region

• Himalayan region: Snow leopard, yak, Tibetan antelope (chiru), bharal (blue sheep), red panda, Kashmir stag (hangul).
• Assam / North-East: One-horned rhinoceros (Kaziranga), elephant, wild buffalo.
• Peninsular India forests: Bengal tiger, leopard, wild boar, gaur, spotted deer.
• Gir Forest, Gujarat: Asiatic lion — found ONLY here; India is the only country with both tigers and lions.
• Desert (Rann of Kutch, Thar): Indian wild ass, blackbuck, chinkara, great Indian bustard, camel.
• Wetlands/rivers: Gangetic dolphin (national aquatic animal), gharial, mugger crocodile.
• Coasts and islands: Sea turtles (Olive Ridley), dugong, coral reef species.

Why wildlife is endangered

• Hunting and poaching for skin, ivory, horns (rhino), and bones (tiger).
• Habitat loss due to deforestation, agriculture expansion, dams, mining, and urbanisation.
• Pollution — rivers, air, and land pollution harm aquatic and terrestrial animals.
• Forest fires and natural disasters.
• About 1,300 plant species are endangered and 20 species are already extinct in India.

Project Tiger (1973)

• Launched in 1973 by the Indian Government to protect the Bengal Tiger — India's national animal.
• Tiger population had fallen to about 1,827 in 1972 due to poaching and habitat destruction.
• India now has over 3,000 tigers — the highest tiger population of any country in the world.
• Important tiger reserves: Jim Corbett (Uttarakhand — FIRST Tiger Reserve), Ranthambore (Rajasthan), Sunderbans (West Bengal), Bandipur (Karnataka), Periyar (Kerala), Kanha (MP).
• Project Tiger is considered one of the most successful wildlife conservation programmes in the world.

Other conservation projects

• Project Elephant (1992): Protects Asian elephants and maintains elephant corridors.
• Project Rhino: Conservation of the one-horned rhinoceros (Kaziranga, Assam).
• Project Great Indian Bustard: Critically endangered grassland bird; found in Rajasthan.
• Project Crocodile: Conservation of gharial, mugger, and saltwater crocodiles.

8. Conservation — Protected Areas and National Policy

Conservation means the wise, sustainable use and management of natural resources so that they are available for future generations. India has a well-developed system of protected areas.

Protected Areas Network

Three zones of a Biosphere Reserve

• Core Zone: Strictly protected; NO human activity; only scientific study under special permission.
• Buffer Zone: Limited research and educational activities permitted.
• Transition Zone: Human habitation and use permitted in a sustainable manner.

National Forest Policy and other initiatives

• National Forest Policy (1988): Aims to maintain 33% of India's total land area under forest cover (current cover is about 21–22%).
• Joint Forest Management (JFM): Communities participate in forest protection and share the benefits.
• Social Forestry: Planting trees on public and private land to meet people's daily needs for fuel, fodder, and timber.
• Botanical Gardens: Government gives financial help to botanical gardens for conservation of plant species.
• Zoological Gardens: Help in breeding endangered species in captivity.

Role of forests in ecology

• Regulate the water cycle — forests absorb rainfall, recharge groundwater, and reduce runoff.
• Prevent soil erosion and maintain soil fertility.
• Absorb CO2 and release oxygen — crucial carbon sinks for fighting climate change.
• Maintain biodiversity and provide habitat for wildlife.
• Influence local climate by moderating temperature and humidity.
• Provide livelihood to millions of tribals and forest-dwelling communities.

9. Solved NCERT Exercise Questions

Q1. Choose the right answer.

(i) To which one of the following types of vegetation does rubber belong?

Answer: (c) Tropical Evergreen. Rubber thrives in high-rainfall, high-humidity conditions typical of tropical evergreen forests. In India it is grown in Kerala, Tamil Nadu, and Karnataka where rainfall exceeds 200 cm.

(ii) Cinchona trees are found in the areas of rainfall more than:

Answer: (b) 100 cm. Cinchona (source of quinine, used against malaria) needs well-distributed, heavy rainfall and is found in tropical and montane forests of India.

(iii) In which of the following states is the Shola forest found?

Answer: (b) Kerala (also Tamil Nadu and Karnataka). Sholas are patches of subtropical broadleaf forest found in the valley hollows of the Nilgiris, Anamalais, and Palani hills — separated by open grasslands.

Q2. Answer the following questions briefly.

(i) Define an ecosystem.

Answer: An ecosystem is a system formed by the interaction of all living organisms — plants, animals, micro-organisms — with each other and with the physical and chemical environment in which they live. For example, a forest ecosystem includes trees, animals, soil organisms, climate, water, and soil all acting together in an interdependent web.

(ii) What factors are responsible for the distribution of plants and animals in India?

Answer: The distribution of plants and animals in India is determined by three major factors:

• Relief — altitude, slope, and drainage determine moisture availability and soil formation.
• Climate — temperature, rainfall, humidity, photoperiod (sunlight hours), and wind.
• Soil — type, texture, depth, and moisture-holding capacity of soil determines which plants can grow.

Together these factors create diverse habitats supporting India's enormous variety of flora and fauna.

(iii) What is a biosphere reserve? Name any two biosphere reserves of India.

Answer: A biosphere reserve is a large protected area designated to conserve entire ecosystems — the full range of plants, animals, and their habitat — while also promoting sustainable use by local communities. It has three zones: core (strictly protected), buffer (limited research), and transition (human use). Two examples:

• Nilgiri Biosphere Reserve — first in India (1986); covers parts of Tamil Nadu, Kerala, and Karnataka.
• Sunderbans Biosphere Reserve — West Bengal; covers the mangrove delta; also a UNESCO World Heritage Site and home to the Royal Bengal Tiger.

(iv) Name two animals having their habitat in tropical rainforests.

Answer: (1) Elephant — found in the tropical rainforests of the Western Ghats and North-East India. (2) One-horned rhinoceros — found in the tropical forests and grasslands of Assam (Kaziranga National Park).

(v) Distinguish between flora and fauna.

Q3. Distinguish between (a) Evergreen and Deciduous forests

Q4. What is meant by the term 'vegetation'? Distinguish between natural and modified vegetation.

Answer: Vegetation refers to the plant life covering the earth's surface in a region. Natural vegetation (virgin vegetation) is the plant community that grows naturally without any human aid, undisturbed for a long period. Modified vegetation (cultivated vegetation) has been altered by humans — e.g., agricultural crops, planted forests, orchards, and gardens. In India, a large portion of original natural vegetation has been replaced by modified vegetation as humans have cleared forests for farming, settlements, and industry over centuries.

10. Quick Revision — Key Tables and Memory Points

Numbers to remember for the board exam

• Project Tiger launched: 1973
• Project Elephant launched: 1992
• Nilgiri Biosphere Reserve (first in India): 1986
• National Forest Policy target: 33% forest cover
• Sunderbans: world's largest mangrove forest
• National animal: Bengal Tiger | National bird: Peacock
• National aquatic animal: Gangetic Dolphin
• Asiatic Lion: found ONLY in Gir Forest, Gujarat
• India's share of world's species: approx. 8%
• India's plant species: ~47,000 | Animal species: ~90,000
• Biosphere Reserves in India: 18 | National Parks: ~103 | Wildlife Sanctuaries: ~535
• First Tiger Reserve: Jim Corbett (Uttarakhand)

Common mistakes to avoid

• Do NOT confuse Evergreen (no dry season, leaves NOT shed together) with Deciduous (dry season, leaves shed).
• Do NOT say the Sunderbans is only a mangrove forest — it is also a National Park, a Biosphere Reserve, and a UNESCO World Heritage Site.
• Do NOT mix up National Park (most strict — no human activity) with Wildlife Sanctuary (limited activity allowed).
• A Biosphere Reserve is NOT more restricted than a National Park — it allows human habitation in its transition zone.
• Project Tiger = 1973; Project Elephant = 1992. Do not swap these years.
• Tropical Deciduous is the most widespread — NOT Tropical Evergreen.
• The Sundari tree gives the Sunderbans its name — not the other way around.
• Cultivated crops, orchards, and gardens are NOT natural vegetation — only undisturbed virgin plant life counts.