STAND STRUCTURE, SPECIES COMPOSITION AND CARBON ACCUMULATION IN THE POLYHALINE ZONE OF THE SUNDARBANS MANGROVE FOREST, BANGLADESH.

Abstract

Mangrove stand structure may have direct impact on the conditions and functioning of mangrove ecosystems, and it can modify the distribution and richness of fauna in these habitats. The mangrove ecosystem throughout the polyhaline zone of Sundarbans Mangrove Forest (SMF) was chosen for research on stand structure, biomass accumulation, and carbon storage. Field data were collected from seven sample plots measuring an area of 700 m². Species diversity, diameter class distribution vs. biomass carbon, and species-specific contributions to total biomass carbon were examined. Excoecaria agallocha has maintained its dominance (42.4%, relative density) of the stand. The mean above and below-ground biomass carbon stock of the mangrove community was 197.1 and 173.2 Mg ha^-1 yr^-1, respectively. Avicennia officinalis accounted for only 16.7% individually, contributing over 45% to the total biomass carbon while Xylocarpus mekongensis was the second-highest contributor. The majority of the tree’s diameter were around 10–5 cm, but their share of the total above-ground biomass carbon is only 12%. In comparison, a significant amount of biomass carbon is contributed by tree species with a diameter of 35 to 40 cm, which account for only 3.9% of all trees, but account for 17.8% of the total above-ground biomass carbon. Mangrove communities growing in the polyhaline zone of the SMF have significant species diversity and considerable carbon stock. These findings should be incorporated in future decision-making processes for the area and contribute to a better understanding of the SMF’s function in reducing the effects of global warming.