Natural Vegetation and Wildlife Class 9 NCERT

Chapter Overview: Why India Has Diverse Vegetation

India has a wide variety of natural vegetation because environmental conditions change sharply from place to place. The Western Ghats and north-eastern hills receive heavy rainfall, so dense evergreen forests can survive there. Rajasthan and parts of Gujarat receive very little rainfall, so thorny bushes and drought-resistant plants dominate. The Himalayas show a vertical change: lower slopes have broad-leaved forests, higher slopes have coniferous trees, and very high areas have alpine grasslands. Temperature, rainfall, soil, relief and sunlight work together; if one factor changes, the plant community changes too. Wildlife also depends on these habitats. For example, mangrove forests protect coastal biodiversity, while grasslands and forests support deer, elephants, tigers and many birds.

Key Terms You Must Know

Natural vegetation

Plant life that grows naturally in an area without being planted or directly managed by humans over a long period.

Flora and fauna

Flora means the plant species of a region, and fauna means the animal species found there.

Biome

A large ecological region with similar climate, vegetation and wildlife, such as forests, grasslands or deserts.

Endemic species

Species found naturally only in a particular region, such as some animals and plants restricted to the Andaman and Nicobar Islands or Western Ghats.

Endangered species

Species whose numbers have declined so much that they may become extinct if not protected.

How to Identify a Vegetation Type in Exam Questions

1. Check rainfall first — High rainfall above about 200 cm usually suggests tropical evergreen forests. Rainfall between about 70 and 200 cm often supports tropical deciduous forests, while less than about 70 cm points towards thorn forests and scrub.
2. Link temperature and location — Warm, humid coastal or north-eastern regions differ from cold Himalayan slopes. In mountains, vegetation changes with altitude because temperature decreases as height increases.
3. Look for plant features — Evergreen trees remain green because they shed leaves at different times. Deciduous trees shed leaves in the dry season. Thorn plants have long roots, small leaves and spines to reduce water loss.
4. Add examples for full marks — Always support the answer with regions and species. For example, write teak and sal in deciduous forests, ebony and mahogany in evergreen forests, and sundari trees in mangroves.

Worked Examples: Apply the Concepts

• Example 1: A question says: A region has rainfall over 200 cm, high temperature and no definite dry season. Identify the vegetation. Step 1: Rainfall is very high, so reject thorn and deciduous forests. Step 2: No definite dry season means trees do not shed leaves together. Step 3: Warm and wet climate supports dense multilayered forests. Final answer: Tropical evergreen forests, found in areas such as the Western Ghats and north-eastern India.
• Example 2: Explain why thorn forests occur in Rajasthan. Step 1: Rajasthan has low and uncertain rainfall. Step 2: Plants must conserve water to survive. Step 3: They develop long roots, small leaves, thick stems and thorns to reduce transpiration and reach groundwater. Final answer: Thorn forests and scrub occur because the hot, dry climate favours drought-resistant vegetation.
• Example 3: Why are mangrove forests important? Step 1: Mangroves grow in tidal coastal areas where fresh and salt water mix. Step 2: Their roots trap silt, reduce coastal erosion and protect shorelines during storms. Step 3: They provide breeding grounds for fish, birds and reptiles. Final answer: Mangroves are ecologically valuable coastal forests; the Sundarbans are a major example.

Major Vegetation Types: Exam-Ready Points

• Tropical evergreen forests: Found in very wet regions like the Western Ghats, Andaman and Nicobar Islands and north-eastern states; trees include ebony, mahogany and rosewood.
• Tropical deciduous forests: The most widespread forests in India; trees such as teak, sal and shisham shed leaves in the dry season to conserve water.
• Thorn forests and scrub: Found in dry regions like Rajasthan, Gujarat, Haryana and parts of Madhya Pradesh; plants have spines, long roots and small leaves.
• Montane forests: Found in the Himalayas and other mountain areas; vegetation changes with altitude from broad-leaved trees to conifers and alpine grasslands.
• Mangrove forests: Found in tidal deltas and coastal areas; the Sundarbans have sundari trees and support rich wildlife including the Royal Bengal Tiger.

Common Mistakes and Board Answer Tips

Do not write only a list of forest names. CBSE answers score better when you connect climate, region, plant adaptation and examples. A common mistake is confusing evergreen and deciduous forests: evergreen forests do not shed all leaves in one season, while deciduous forests shed leaves during the dry period. Another mistake is treating wildlife conservation as only protecting animals; it also means protecting habitats, controlling poaching, creating national parks and reducing human pressure on forests.

Practice Questions with Solutions

• Q: Define natural vegetation and explain two factors that influence it. A: Step 1: Natural vegetation is plant life that grows naturally without direct human planting or care. Step 2: Rainfall influences density and type of vegetation; high rainfall supports dense forests, while low rainfall supports thorny scrub. Step 3: Temperature and relief also matter; mountain slopes have different vegetation at different heights because temperature falls with altitude. Final answer: Natural vegetation is self-growing plant life, mainly controlled by rainfall, temperature, relief, soil and sunlight.
• Q: Distinguish between tropical evergreen forests and tropical deciduous forests. A: Step 1: Tropical evergreen forests grow in areas of very high rainfall, generally above 200 cm, and remain green throughout the year. Step 2: Tropical deciduous forests grow in regions with seasonal rainfall and have a dry season. Step 3: Evergreen forests include trees such as ebony and mahogany, while deciduous forests include teak, sal and shisham. Final answer: Evergreen forests are dense, wet-climate forests with no common leaf-shedding season; deciduous forests shed leaves in the dry season to conserve water.
• Q: Why are thorn forests adapted to dry regions? A: Step 1: Dry regions receive low and irregular rainfall, so water availability is limited. Step 2: Plants reduce water loss by having small leaves, waxy surfaces, thorns and thick stems. Step 3: Long roots help them reach underground water. Final answer: Thorn forests survive in dry regions because their structure reduces transpiration and helps them absorb scarce water efficiently.
• Q: Suggest three measures for conserving wildlife in India. A: Step 1: Protect habitats by creating and maintaining national parks, wildlife sanctuaries and biosphere reserves. Step 2: Stop illegal hunting and trade through strict laws and monitoring. Step 3: Involve local communities in conservation so forests and animals are protected along with livelihoods. Final answer: Wildlife can be conserved through protected areas, anti-poaching measures, habitat protection and community participation.

Frequently Asked Questions