Mangroves, coastal salt marshes and seagrass beds, as the typical coastal blue carbon ecosystems, have been widely recognized for their remarkable capacity in carbon storage. Vegetation carbon pool and sediment (or soil) carbon pool were considered to be the major carbon pools within the coastal blue ecosystems and their variations determined the overall carbon sequestration of the ecosystems. Unlike the terrestrial ecosystems, the two major carbon pools of blue carbon ecosystems could interact with each other through sediment dynamic processes. This study investigated the interaction between vegetation and sediment carbon pools of coastal wetlands, through in situ observations and laboratory control experiments. Different scenarios have been taken into account and examined in this study, including interspecific competition, presence of tidal creeks and dykes, and typhoon events. The main findings indicate that exotic species invasion enhanced the carbon sequestration ability through sediment dynamic mediation, whilst the presence of tidal creeks and dykes further mediated the spatial variation in carbon sequestration ability. Compared with calm weather conditions, typhoons triggered a strong interaction between two carbon pools together with the subsequent carbon pool regulation. The output of this work suggests that the sediment dynamics could not be ignored in future blue carbon studies to better understand the carbon pool interaction.
 

carbon pool, vegetation, biogeomorphology, sediment dynamics, intertidal flat