Species-specific biomass and carbon flux in Sundarbans mangrove forest, Bangladesh: Response to stand and weather variables

Abstract

The species-specific potentiality of mangroves in terms of ecosystem services is not well understood. Therefore, this study addressed the carbon sequestration and litterfall production potentiality of six major species in Sundarbans, Bangladesh, by evaluating three consecutive years of inventory data, including the stand variables and weather events impacts on them. The total mean aboveground, belowground biomass, biomass accumulation, and carbon accumulation rate were 243.4 Mg ha−1, 132.2 Mg ha−1, and 14.3 Mg ha−1 yr−1, 7.2 Mg ha−1 yr−1, respectively. Carbon stocks and sequestration rates are significantly influenced by stand variables such as diameter, density, and species composition. Large-sized trees and stands with lower density sequester more carbon than small-sized trees, and higher density stands. Among species, Avicennia officinalis contributed higher carbon to carbon stocks and also significantly different from other species for sequestering carbon, whereas Aglaia cucullata was the lowest. Mean annual litterfall was 10.01 Mg ha−1 yr−1, with the maximum litterfall for Hereteira fomes (19.2 Mg ha−1 yr−1) during the late summer or wet season (e.g., April to August). Litterfall showed a significant positive (p < 0.001) relation to weather variables such as rainfall, temperature, wind, etc. This study reports that the rate of carbon sequestration in Sundarbans was 17.21 Mg C ha−1 yr−1, which corresponds to 62.6 Mg ha−1 yr−1 CO2. High carbon stocks, carbon sequestration, and litterfall production rate in Sundarbans demonstrate the significance of mangrove species and Sundarbans in the global carbon budget. This information can be used in species selection for plantation, species conservation, and ecosystem management purposes at the regional and global levels.