Sedimentary blue carbon dynamics based on chronosequential observations in a tropical restored mangrove forest

[摘要] Among the many ecosystem services provided by mangroves, thesequestration of large amounts of organic carbon (OC) in marine ecosystems(also known as “blue carbon”) has given these unique ecological environmentsenormous global attention. While there are many studies on the blue carbonpotential of intact mangroves (i.e., naturally growing), there have beenvery few studies on restored mangroves (i.e., planted). This study aims toaddress this knowledge gap by examining the sediment development processduring the early colonization (rehabilitation) of mangroves in an OC-poorestuary in Panay Island, Philippines. Based on source apportionment ofmultiple end-members in the sedimentary organic matter, the contribution ofmangrove plant material was higher at the older sites compared to theyounger sites or bare sediments where there is a higher contribution of riverineinput. A clear increasing gradient according to mangrove development wasobserved for bulk OC (0.06–3.4  µ mol g −1 ), porewater OC(292–2150  µ mol L −1 ), sedimentary OC stocks (3.13–77.4 Mg C ha −1 ), and OC loading per surface area (7–223  µ mol m −2 ).The estimated carbon accumulation rates (6–33 mol m −2  yr −1 ) basedon chronosequence are within the global ranges and show an increasingpattern with the age of mangroves. Hence, the sediments of relatively youngmangrove forests appear to be a significant potential C sink, and short-termchronosequence-based observations can efficiently define the importance ofmangrove restoration programs as a potential carbon sequestration pathway.

[学科分类] 大气科学