Mangroves: An Organic Carbon Stabilizer

Mangrove ecosystems are acknowledged for their capacity to sequester organic carbon, yet they face significant risks from climate change and anthropogenic activities. The complexity of these impacts is compounded by a lack of comprehensive understanding of organic carbon stabilization within these environments. While considerable research has been devoted to understanding organic carbon stabilization in terrestrial and marine contexts, coastal vegetated zones, particularly mangroves, have been relatively neglected. The natural resistance of organic matter to deterioration, its physical encasing, and its physical and chemical relationship to minerals and metals are the reasons given by both continental and maritime models for the stabilization of organic carbon. This chapter summarizes the current understanding of the process of organic carbon stability in mangrove soils and emphasizes the need for additional study to resolve unanswered concerns. The stabilization mechanisms of organic carbon appear to differ between mangrove peat and mineral soils. For mineral soils in mangrove ecosystems, physicochemical stabilization processes are deemed crucial but remain insufficiently explored. The organic carbon retention in mangrove peat is thought to be primarily dependent on the naturally hardy nature of the mangrove roots and the inhibition of phenol oxidase metabolism under an oxygen-deprived environment. The effects of salinity on organic carbon fixation may be significant in both soil types. This chapter suggests that contributions from belowground biomass and external organic inputs to mangrove forests might be underappreciated. Further research is imperative to refine carbon budget estimations and resolve the paradox of ongoing organic carbon accumulation in mangroves despite the potential for high rates of decomposition and considerable lateral carbon exports.