Biogeomorphology of Mangroves

Mangrove biogeomorphological processes operate on the timescales of short-term promotion of accretion, medium-term responses to relative sea level (RSL) changes, and long-term migration and the consequent genetic matter distribution. This review brings together understanding from different disciplines to make linkages and clarify gaps for future research. Biogeomorphic values include protection from high-energy events and direct contribution to vertical accretion, contributing to mitigation of relative sea level rise (RSLR). Organic accumulation also provides carbon sequestration and facilitates mangrove deterministic processes. Biogeomorphic responses to medium-term processes of RSL change are different between mangrove settings. Pollen analysis of mangrove community change with elevation determination shows that mangroves opportunistically colonize suitable conditions during more rapid RSLR in terrigenous, lagoon and low island settings, where dominated by minerogenic sediment. RSL fall also causes mangroves to follow habitat migration. In conditions of slow RSLR and reduced disturbance, mangroves can deterministically maintain their own habitat through biogenic processes of accretion in terrigenous river-dominated, lagoonal, and low island settings. These scenarios reveal that the long-standing opportunistic and deterministic interpretations of mangroves are situational rather than alternative.