Carbon budgets of multispecies seagrass beds at Dongsha Island in the South China Sea

Biomass, production, consumption, and detrital export and decomposition of four dominant seagrass species were determined in tropical multispecies beds as a means of constructing carbon budgets. These processes varied among seagrass species. The living biomass held a high carbon stock. The leaf production of multispecies beds was also higher than that of monospecific beds. However, the sediment organic carbon stock was much lower than the global median stock, which was likely due to decomposition of most of the detritus and export to nearshore waters. Reliable measurements of decomposition and export are particularly needed to estimate the organic carbon storage rate.