VEGETATION OF INDIA
The Indian vegetation can be classified into five major catcgorics :
Tropical Evergreen or Rain Forest Type
These arc further subdivided into three categories on the basis of rainfall:
Tropical Wet Evergreen Forest
- In areas receiving more than 300 cm of rainfall and a short dry season. Strip along the Sahydris upto 1 370 metre, the hilly regions of North-cast India. the Tarai region of eastern Himalaya and the An daman and Nicobar islands have evergreen forests.
Tropical Semi-Evergreen Forest
- In areas of 200 cm of rainfall, found along the margins of wet ever green forest.
Tropical Moist-Deciduous Forest
- Typical monsoon forest found in the areas of Western Ghats, Eastern Ghats, Chotanagpur plateau, M.P. and the Bhabar and Tarai regions of the Himalaya receiving 102-200 cm. rainfall. Open forests, Sal, Teak and Sandalwood are trees of economic importance.
Dry Tropical Types
Occurs in areas of 75-125 cm of rainfall and subdivided into three types:
Tropical Dry Deciduous
- Biotic variation of moist deciduous forests degenerating on the drier side into thorny forests, occurs over large areas between Thar and Hi malayan and interior of Sahyadris. Teak, Tendu, Sal, Palm, Laural, 'Chair are important trees.
Tropical Dry Evergreen Forests
- Confined to the coastal areas of Andhra Pradesh and Tamilnadu, because these areas receive 100 cm of rainfall mostly during winter season through North- east monsoon. Neem, Tamarind, Palm, Casuarina are important trees.
Tropical Thorn Foreits
- Occurs in low rainfall (less than 75 cm) regions of Rajasthan and Gujarat. Stunted trees like Accasia are common with scrubs and xerophytic bushes in the drier side. Such forests also occur in the interior regions of peninsula having rain-shadow effect of Western Ghats.
Himalayan Montane Vegetation
The Himalayan vegetation is classified as Tropical, Temperate and Alpine mainly on the basis of altitude and rainfall.
- Tropical evergreen montane forest is confined to the humid foothills of eastern and central Himalayas upto a height of 1500 metre.
- Ironwood, oak, chestnut, bamboos, etc, are found in these forests.
- Temperate forests are formed at altitutdes between 1500 and 3500 meter containing conifers and broad leaved temperate trees.
- Pine is the dominant species at 920-1640 metre altitude. Deodar, a highly valued species grows mainly in the western part of the Himalayan range upto 2700 metre.
- The alpine zone begins above the tree line at on altitude of 3200-3500 metre, extending upto 3900 metre in the western Himalaya.
- Juniper, rhododendron, mosses and lichen are characteristics vegetation.
Peninsular Montane Vegetation
- The subtropical forests occur on the lower slopes of Sahyadris and in Satpura and Maikal range. At higher levels the temperature is lower but rainfall is higher, therefore temperate forests are denser and called as Sholas in the Nilgiri, Anna-malai, and Palani hills. Mangolia, laurel, rhododendron, eucalyptus, cinchona are found in the forest.
- In the tide washed coast dense mangrove forests flourish with peculiar edaphic adaptations. The seaward fringes and islands of the deltas of the Ganga, Mahanadi, Krishna and Godavari are belt of dense tidal forest. The great Sundarban is a typical example inhabited by sundari trees.