Natural Vegetation and Forest Types of Tamil Nadu

Natural Vegetation

Natural vegetation refers to the forest cover. Landforms, nature of soil, temperature and rainfall are the major factors that control the distribution of natural vegetation. As per National Forest Policy, 1988, a minimum of one-third of the total geographical area must be under forest cover. The total forest cover of Tamil Nadu is far lower than this. According to the Tamil Nadu State of Forest Report - 2017 assessment, the area under forest in the state is 26,281 sq.km, which constitutes 20.21% of the total area. Tamil Nadu constitutes 2.99% of India’s forest cover. The forest types in the state varies from wet evergreen to scrub forests.

Forest Types

The forest in the state is broadly divided into five types as follows

Tropical Evergreen Forest

This forest type is found in the regions that receive heavy rainfall. It is a dense, multi-layered forest. It is found in the upper slopes of Western Ghats of Tirunelveli, Kanyakumari, the Nilgiris and Coimbatore districts. The major tree species of this forest are cinnamon, Malabar ironwood, panasa, java plum/jamun, jack, kindal, ayani and crape myrtle. The semi-evergreen type of forest in the state is found over the regions of sub-tropical climate over the Eastern Ghats. The prominent regions are Servarayan, Kollimalai and Pachaimalai. Species of Indian mahogany, monkey teak, woolly cassia, jack and mango trees are common in this region.

Montane Temperate Forest

It is found in sheltered valleys of Anaimalai, Nilgiris and Palani hills over a 1000 metres altitude. They are known as ‘Sholas’. The trees in this forest are evergreen and usually short. Nilgiri champa, wights litsea and rose apple are the common trees found in this forest.

Tropical Deciduous Forest

This type of forest lies in the margin of semi -evergreen and evergreen forests. The trees in this forest shed their leaves during the dry season. The trees reach up to a height of 30 metres. Some trees of this forest are silk cotton, kapok, kadamba, dog teak, woman's tounge, axlewood and siris. Bamboos are also common in this type of forests. Some trees of this forest are economically important.

Mangroves Forest

This type of forest is found in the coastal areas, river deltas, tails of islands and over sea faces where accretion is in progress. The vegetation is typically evergreen, moderate in height and has leathery leaves. The vegetation of this forest is adapted to survive in tidal mud and salt water. Asiatic mangrove, white mangrove, wild jasmine/Indian pivot etc. are some of the notable trees of this forest. Pichavaram, Vedaranyam, Muthupet, Chatram and Thoothukudi are the places in Tamil Nadu where the mangrove forest is found to a considerable extent.

Tropical Thorn Forest

Thorn forest in Tamil Nadu is found where there is a little rainfall. These forests are found from plains up to 400 meters altitude. The common trees of this forest are rusty acacia, wheel, neem and palm. Shrubs are common vegetation in this type of forest. This type of forest is found in the districts of Dharmapuri, Ramanathapuram, Virudhunagar and some parts of interior districts.

Natural Vegetation Pichavaram mangrove forest is located near Chidambaram, Cuddalore district. This is the second largest mangrove forest in the world covering about 1,100 hectares (11 sq.km) of area. It is separated from the Bay of Bengal by a sandbar. It consists of species like Avicennia and Rhizophora.

Role of Mangroves in Coastal Zone Management.

Mangroves helps in the prevention of coastal erosion from waves and storms. It also protects coral reefs and sea grass meadows from being smothered in sediments.