English: Organic carbon sequestration in vegetated coastal habitats
Conceptual diagram of key factors influencing organic carbon sequestration in vegetated coastal habitats (VCHs). (1) High sedimentation rate due to presence of plants capturing particles from the water column, increases burial of surface applied organic matter. (2) High input of organic material increases microbial activity at the sediment surface, ensuring low O2 penetration. (3) High carbon accumulation in deep, anoxic sediment (cm-m). (4) Low resuspension of sediment due to reduced flow across sediment. (5) Sediment acidification with depth potentially leading to inhibition of bacterial growth. Hence, VCHs, such as mangrove forests, salt marshes and seagrass meadows, are characterized by three important environmental properties: (i) high organic loading, (ii) high carbon burial rate, and (iii) efficient protection of the buried carbon, as opposed to unvegetated sediment.