Carbon Stocks in Natural and Planted Mangrove forests of Mahanadi Mangrove Wetland, East Coast of India

Abstract

Mangrove forest ecosystem is one of the important carbon sinks in the tropics. The role of mangrove forests in mitigating climate change through reduced deforestation is well recognized. The present field study aimed to estimate the carbon stocks of Mahanadi Mangrove Wetland (MMW), east coast of India. Carbon stocks were estimated in vegetation and soil of natural mangrove forest stands and new mangrove plantation stands. The mean of carbon stock in natural stands was 143.4 +/- 8.2 Mg C ha(-1) (vegetation 89.1 +/- 8.9 and soil 54.3 +/- 3.0 Mg C ha(-1)) and plantation at 151.5 +/- 7.9 Mg C ha(-1) (vegetation 90.6 +/- 16.2 and soil 60.9 +/- 5.6 Mg C ha(-1)). The mean overall C-stock of natural stands and plantations was 147.0 +/- 8.1 Mg C ha(-1) (vegetation 89.4 +/- 7.6 and soil 57.6 +/- 3.2 Mg C ha(-1)), which is 1.6 times higher than that in forests of Odisha. A positive correlation (r = 0.87) was found between vegetation biomass and soil organic carbon in the surface soil (0-30 cm), indicating the role of vegetation in building surface soil/sediment organic carbon. The 6651 ha of mangrove forests in the MMW is estimated to store 0.98 Mt of C, which is equivalent to 3.59 Mt of CO(2)e. The present study reveals that MMW stores substantial amount of atmospheric carbon and therefore needs to be conserved and sustainably managed to maintain as well as increase carbon storage. Further, mangrove plantations, on a per unit area basis, can sequester as much carbon as natural stands.