Quick Revision Notes: Class 9 Social Science (Geography)

Chapter: Natural Vegetation and Wildlife

Natural Vegetation: Refers to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time (also known as Virgin Vegetation).
Endemic Species: The species of plants and animals which are exclusively confined to a particular area (native to a region).
Exotic Species: Plants and animals that originate from outside the region or country (foreign species).
Flora: Denotes plants of a particular region or period.
Fauna: Denotes the species of animals of a particular region or period.
Biodiversity / Ecosystem: A broad variety of living organisms (plants and animals) interacting with each other and their physical environment.

The distribution and variation of flora and fauna are determined by two main factors:

Relief:
- Land: Nature of land influences vegetation type. Fertile lands are generally devoted to agriculture, while rough and undulating terrains are areas for grasslands and woodlands.
- Soil: Different types of soils provide bases for different types of vegetation (e.g., sandy soils support cactus/thorny bushes, alluvial soils support mangrove or wet marshy plants).
Climate:
- Temperature: Character and extent of vegetation are mainly determined by temperature along with humidity and precipitation.
- Photoperiod (Sunlight): Variation in duration of sunlight at different places is due to differences in latitude, altitude, season, and duration of the day. Trees grow faster in summer due to longer sunlight hours.
- Precipitation (Rainfall): India receives rainfall mostly due to advancing monsoon. Areas of heavy rainfall have denser vegetation compared to areas of low rainfall.

India's natural vegetation is broadly classified into five major types:

Rainfall: More than 200 cm with a short dry season.
Characteristics: Trees reach great heights up to 60 meters or more. Since there is no definite time for trees to shed their leaves, these forests appear green all year round.
Important Trees: Ebony, mahogany, rosewood, rubber, and cinchona.
Common Animals: Elephants, monkey, lemur, deer, one-horned rhinoceros (in Assam and West Bengal).

This is the most widespread forest type in India.
Rainfall: Between 200 cm and 70 cm.
Sub-divisions:
- Moist Deciduous: Rainfall 200–100 cm. (Teak, bamboo, sal, shisham, sandalwood).
- Dry Deciduous: Rainfall 100–70 cm. (Tendu, palas, amaltas, bel, khair, axlewood).
Characteristics: Trees shed their leaves for about 6 to 8 weeks in dry summer.
Common Animals: Lion, tiger, pig, deer, elephant, and a variety of birds and lizards.

Rainfall: Less than 70 cm.
Characteristics: Consists of thorny trees and bushes. Plants have stunted growth, long roots reaching deep for moisture, and thick, small leaves to minimize evaporation.
Important Trees: Acacias, palms, euphorbias, and cacti.
Common Animals: Rats, mice, rabbits, fox, wolf, tiger, lion, wild ass, horses, and camels.

Characteristics: Vegetation changes with an increase in altitude due to a drop in temperature.
Zones by Altitude:
- 1000m to 2000m: Wet temperate forests (Oak and chestnut).
- 1500m to 3000m: Temperate forests with coniferous trees like pine, deodar, silver fir, spruce, and cedar (found in southern slopes of Himalayas and high altitude areas of South/Northeast India).
- Above 3600m: Alpine vegetation transitions into tundra (Silver fir, junipers, pines, birches; Mosses and lichens at higher altitudes).
Common Animals: Kashmir stag, spotted deer, wild sheep, jackrabbit, Tibetan antelope, yak, snow leopard, squirrels, and bear.

Characteristics: Grown in coastal areas influenced by tides. Mud and silt get accumulated on such coasts. Dense mangroves are varieties of plants with roots submerged under water.
Important Trees: Sundari trees (give the name to Sundarbans delta), agar, kiora.
Common Animals: Royal Bengal Tiger, turtles, crocodiles, gharials, and snakes.

India has about 90,000 animal species, 2,000 species of birds, and 2,500 species of fish (which accounts for nearly 12% of the world's stock).
Mammals: Elephants are the most majestic animals, found in the hot wet forests of Assam, Karnataka, and Kerala. One-horned rhinoceroses live in swampy lands of Assam and West Bengal. Rann of Kachchh is habitat for Wild Ass, and Thar Desert for camels. Indian bison, nilgai, chowsingha, gazel, and various species of deer are also found.
Carnivores: India is the only country in the world that has both tigers and lions. The natural habitat of the Indian lion is the Gir forest in Gujarat, while tigers are found in Madhya Pradesh, the Sundarbans of West Bengal, and Himalayan regions.
Migratory Birds: India is famous for migratory birds. Birds like Siberian Crane arrive in winter in places like Keoladeo National Park (Bharatpur, Rajasthan).

Greed of human beings, hunting for commercial use, pollution, cutting down of forests (deforestation) for agriculture and habitation have endangered ecosystems.
Many species have become extinct or endangered.

Biosphere Reserves: Setup to protect flora and fauna (e.g., Sundarbans, Nanda Devi, Gulf of Mannar, Nilgiri, Nokrek, Great Nicobar, etc.).
Wildlife Sanctuaries & National Parks:
- 103 National Parks, 535 Wildlife Sanctuaries, and Zoological Gardens are set up to take care of natural heritage.
Project Tiger, Project Rhino, Project Great Indian Bustard: Special financial and administrative schemes launched to protect endangered species.
Financial and Technical Assistance: Provided to many botanical gardens by the government since 1992.