Mangrove Forest Dynamics in Relation to Sediment Input at the Mouth of Sematan River, Sarawak, Malaysia

Abstract

Stand structure dynamics of mangrove forest induced by sedimentation was studied on a small river-mouth bar in Sematan, Sarawak, Malaysia as a case study concerning dynamics between habitat and vegetation development in deltaic setting. The active invasion of Rhizophora spp. into Sonneratia alba stand was observed. Furthermore, decline of S. alba at inner part of the forest was observed. Grain size analysis suggested that the complicated root systems of Rhizophora spp. had accelerated the sedimentation of finer material in the mangrove forest. As this sedimentation had progressed, pneumatophores of S. alba were buried and S. alba trees were in decline. Judging from the above-ground biomass and tree density, this vegetation change had taken place before well development of S. alba pure stand. Root productivity of Rhizophora spp. resulted in increments of organic carbon content in sediments corresponding with this vegetation change.