The effects of stand-age and inundation on carbon accumulation in mangrove plantation soil in Namdinh, Northern Vietnam

Abstract

An investigation was conducted on Kandelia candel plantations in Namdinh Province, Northern Vietnam to elucidate the influences of stand-age and inundation on carbon accumulation in mangrove soil. The research plots were set according to stand-age and inundation. Carbon accumulation in the soil was estimated. There was a depth-related distribution of C content in mangrove soil. In the surface soil layer, carbon content seemed to increase gradually with the growth of mangroves. It was implied that the vertical profile of C content might reflect potential carbon accumulation caused by the former mangrove vegetation, decomposition of subsurface accumulation induced by root development of newly planted mangroves, and re-accumulation of organic matter from new plantations. Carbon accumulation of the studied mangrove area was considerably high, ranging from 71 to 82 ton C ha -1 . The total C accumulation (including plant C) appeared to increase exponentially with vegetation age, with an annual rate of 9.7 %. The effect of stand-age could be explained by biomass and anaerobic decomposition that occurred in the sediment. Results of this survey concerning inundation clearly show that carbon accumulation in the soil of a plantation grown in low intertidal elevation was high and low in mangroves grown in high intertidal elevation. Different inundation conditions would cause different biomass and anaerobic conditions. Thus, inundation plays an essential role in the process of carbon storage in mangrove soil.