NIOS Class 10 Social Studies Chapter 11 Biodiversity in India Part 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Title: Biodiversity

Biodiversity refers to the total number of genes, species and ecosystems of a region.

  • Genetic diversity
  • Species diversity
  • Ecosystem diversity

Status of Biodiversity in India

  • The Biodiversity will naturally increase as we move from the poles towards the equator.
  • India got only 2.42 % of the world՚s land area but its contribution to the world՚s biodiversity
  • Which is approximately 8 % of the total number of species which is estimated to be 1.75 million 8 % of the world species are found in India.
  • Around 45000 plants species comprising about 12 % of world՚s flora are found in Indian forests.
  • The North-Eastern region and the Western Ghats are the two of the twelve biodiversity hotspots in the world are in India.

Natural Vegetation in India

Natural Vegetation in India

India can broadly be divided into the following groups:

Tropical Evergreen Forests

  • The forests remain green all year and the leaves don՚t fall.
  • The climate is warm and wet throughout the year with 200 cm of rainfall.
  • The trees reach the height of up to 60 meters normally.
  • Rosewood, ebony, mahogany, rubber, jack wood and bamboo are the popular species.
  • They usually found in the Western Ghats, upper parts of Assam and islands of Lakshadweep, Andaman and Nicobar.

Tropical Deciduous Forests

  • They receive annual rainfall between 75 to 200 centimetres.
  • The trees shed their leaves once a year.
  • These are widespread in the country except in some parts of Deccan Plateau, North-Eastern Region, Western Ghats and Eastern coast.

On Basis of the Availability of Rainfall, Tropical Deciduous Forests Are Further Divided Into

The Moist Deciduous Forests

  • The areas of rainfall between 100 to 200 cm
  • The forest has distributed the foothills of the Himalayas, Jharkhand, Odisha and Chhattisgarh, and eastern slopes of Western Ghats.
  • The Teak, Bamboo, Sal, Shisham, Sandalwood, Khair, Kusum, Arjun, Mahua, Jamun and Mulberry are the important species.

The Dry Deciduous Forests

  • The area receiving annual rainfall between 75 to 100 centimetres annually.
  • These forests are located in the interior parts of the peninsular plateau and the plains of Uttar Pradesh, Madhya Pradesh and Bihar.
  • The species like Teak, Sal, Peepal, and Neem are major tree species.

Thorn Forests

  • The areas with less than 75 centimetres of annual rainfall
  • The climate of this part is mainly dry with an occasional wet period, so it does not support dense vegetation.
  • These are found in the arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh, Haryana, Karnataka, Andhra Pradesh and Maharashtra.
  • The vegetation consists of small trees and bushes with deep roots. The stems are succulent to conserve water.
  • The Leaves are mostly thick and small to minimize evaporation.
  • The Acacia, euphorbias, babul, cacti, khair, date and palms are the major species.

Tidal Forests

  • The forests are found in tidal creeks and swamps influenced by the tides and wetland topography.
  • They have mud, silt and water accumulated on the surface.
  • The Roots and branches of the trees are submerged underwater
  • These are found in the deltas of Sundarbans, Mahanadi, the Godavari, Krishna, Kaveri rivers and in the Andaman and Nicobar Islands.
  • The Sundari is the common tree in Sunderbans while palm, coconut, keora, and agar are other important species of the tidal forest.

Himalayan Forests

  • The forests are found in the mountainous region of the Himalayas.
  • The decreasing in temperature and increase in altitude lead to varied types of vegetation depending upon the slope.
  • Sal and Bamboo are the main species in these areas.
  • Oak, laurel, chestnut, cedar, Silver, Fir, spruce rhododendron are common species.

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