Classification, Distribution, Features, Biodiversity and Functions of Wetlands: A Review

Wetlands include a wide variety of habitats such as marshes, peatlands, floodplains, rivers and lakes and coastal areas such as salt marshes, mangroves and seagrass beds, but also coral reefs and other marine areas no deeper than 6 m at low tide, as well as human-made wetlands such as paddy lands, waste-water treatment ponds and reservoirs. According to Ramsar convention the wetlands are classified as three types viz., coastal/marine wetlands, inland wetlands and human made wetlands. According to UNCC, the estimated wetland cover of world is more than 1210 Million hectares and in that 13-18% are on the Ramsar List of Wetlands of International Importance, which are protected sites. In India 49 major wetland sites) are recognized as Ramsar sites of international importance. India has a variety of wetland ecosystem that support diverse and unique habitats because of diverse climatic condition and it is one amongst the 17 mega diverse countries. Total wetland area of Tamil Nadu is 9.02 lakh ha which is 6.92% of the geographic area and out of them Kancheepuram district is having highest total wetland area of about 8.91%.