Geography: Class 11 (Part 1) — Chapter 5: Natural Vegetation

Tropical Evergreen Forests:

• Distribution: Western slopes of the Western Ghats, hills of the northeastern region, and Andaman and Nicobar Islands.
• Climate: Warm and humid areas with annual precipitation over 200 cm and mean annual temperature above 22°C.
• Structure: Well-stratified with layers closer to the ground covered with shrubs and creepers, followed by short structured trees and tall trees reaching heights up to 60 m or above.
• Key Species: Rosewood, mahogany, aini, ebony.

Semi-Evergreen Forests:

• Found in the less rainy parts of these regions.
• Consist of a mixture of evergreen and moist deciduous trees.
• Key Species: White cedar, hollock, kail.

These are the most widespread forests in India, also known as monsoon forests. They spread over regions receiving rainfall between 70-200 cm and are sub-divided based on water availability:

• Moist Deciduous Forests: Found in areas with rainfall between 100-200 cm (northeastern states, foothills of Himalayas, eastern slopes of Western Ghats, and Odisha). Key species include teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood.
• Dry Deciduous Forests: Cover vast areas with rainfall between 70-100 cm (rainier areas of the Peninsula and the plains of Uttar Pradesh and Bihar). In the dry season, trees shed leaves completely. Key species include tendu, palas, amaltas, bel, khair, and axlewood.

• Distribution: Areas receiving rainfall less than 50 cm, including semi-arid areas of southwest Punjab, Haryana, Rajasthan, Gujarat, Madhya Pradesh, and Uttar Pradesh.
• Characteristics: Plants remain leafless for most of the year and exhibit scrub vegetation.
• Key Species: Babool, ber, wild date palm, khair, neem, khejri, palas. Tussocky grass grows up to 2 m as undergrowth.

In mountainous areas, decreasing temperature with increasing altitude leads to a corresponding change in natural vegetation. These are classified into northern and southern mountain forests:

Northern Mountain Forests (Himalayan Ranges):

• Deciduous forests at the foothills.
• Wet temperate forests between 1,000-2,000 m (oak and chestnut are predominant in northeastern India, West Bengal, and Uttaranchal).
• Pine forests between 1,500-1,750 m, with Chir Pine as a commercial tree. Deodar, a durable wood used in construction, grows in the western Himalayas. Chinar and walnut sustain Kashmir handicrafts.
• Blue pine and spruce appear at altitudes of 2,225-3,048 m.
• Alpine forests and pastures occur between 3,000-4,000 m (silver firs, junipers, pines, birch, rhododendrons). These pastures are used for transhumance by tribes like Gujjars, Bakarwals, Bhotiyas, and Gaddis.
• Mosses and lichens form tundra vegetation at higher altitudes.

Southern Mountain Forests:

• Found in Peninsular India (Western Ghats, Vindhyas, and Nilgiris).
• Temperate forests in the Nilgiris, Anaimalai, and Palani hills are called Sholas.
• Key species of economic significance: Magnolia, laurel, cinchona, wattle.

• India has 3.9 million hectares of wetlands. About 70% is under paddy cultivation.
• Two sites are protected under the Ramsar Convention: Chilika Lake (Odisha) and Keoladeo National Park (Bharatpur).
• Mangrove Forests: Highly developed in the Andaman and Nicobar Islands and the Sunderbans of West Bengal. Other areas include the deltas of Mahanadi, Godavari, and Krishna. They consist of salt-tolerant species and provide shelter to diverse bird species.

Social forestry means the management and protection of forests and afforestation on barren lands to help environmental, social, and rural development. The National Commission on Agriculture (1976) classified it into three categories:

• Urban Forestry: Raising and managing trees on public and privately owned lands in and around urban centres (green belts, parks, roadside avenues).
• Rural Forestry: Comprises agro-forestry and community-forestry.
  • Agro-forestry: Raising trees and agricultural crops on the same land.
  • Community-forestry: Raising trees on public or community land (village pastures, temple lands, roadsides, canal banks) to benefit the community as a whole.
• Farm Forestry: A process where farmers grow trees for commercial and non-commercial purposes on their farm lands.

• Wildlife Protection Act, 1972: Provides the legal framework for conservation and protection of wildlife. It aims to protect endangered species and support conservation areas like National Parks, sanctuaries, and closed areas. It was comprehensively amended in 1991.
• Project Tiger (1973): Launched to maintain a viable population of tigers in India. It has expanded from 9 reserves to 58 tiger reserves, covering 84,487 sq. km across 18 states. The tiger population increased to 3,682 in 2023 (over 75% of the global tiger population).
• Project Elephant (1992): Launched to assist states in ensuring the long-term survival of wild elephants in their natural habitats across 18 states.

A Biosphere Reserve is a unique terrestrial and coastal ecosystem internationally recognised under UNESCO's Man and Biosphere (MAB) Programme. There are 18 Biosphere Reserves in India, 12 of which are recognised on the World Network of Biosphere Reserves.

Note: Bold names indicate sites included in the World Network of Biosphere Reserves of UNESCO.