Mangroves for Protection of Coastal Areas from High Tides, Cyclone and Tsunami

Mangroves are salt-tolerant evergreen dense forests that grow in intertidal zones in tropical and subtropical estuarine regions and mud-flats. Additionally, mangrove forests provide many economical, ecological and environmental values to the people. The total mangrove forest area of the world in 2000 was 1, 37,800 square kilometres spanning 118 countries and territories [1]. According to state forest report of 2015 of Forest Survey of India, mangroves spread over 4,740 sq. km which is about 3 percent of world’s mangrove vegetation and 0.14 per cent of the country's total geographical area. Ecological valuation of the mangroves is mainly for its important role of protection and stabilization of coastal lands and estuarine. Mangroves are important means to control coastal erosion. They not only reduce erosion along the coast but also enhance sediment deposition which is essential to maintain their ecosystems. Several studies have been conducted using remote sensing and GIS which show that there is increased erosion rate in coastal areas where mangrove forests have died. Root architecture of mangroves is such that it traps sediments and prevents erosion from waves and storms. Mangrove forests also play an important role in many other edaphic functions which includes nutrient cycling, facilitation of plant nutrition, disease suppression, water purification, and biological attenuation of pollutants. The paper discusses different studies on coastal erosion, physico-chemical properties of soil, soil nutrition, soil organic carbon and relationship of soil with species composition and structure of mangrove forests in tropical mangrove environment. The study will help in exploring future research for reforestation of deforested mangrove sites, their management and conservation.