Exploring the biomass and carbon stock of mangrove vegetation in Palk Bay's dugong conservation reserve

Abstract

Mangroves are crucial tropical carbon sinks, yet the carbon reserves in Indian mangrove ecosystems, particularly in Palk Bay, remain under-researched. This study evaluates the carbon stock of mangroves in the Dugong Conservation Reserve, Palk Bay, covering 15 zones and 47 transects. Four true mangrove species: Avicennia marina, Rhizophora mucronata, Excoecaria agallocha, and Lumnitzera racemosa, were identified with Avicennia marina contributing most to the biomass and carbon stock. The mean total biomass obtained was 40.09±26.64 Mg/ha, with above-ground biomass of 25.31±18.86 Mg/ha and below-ground biomass of 14.77±7.93 Mg/ha. Zone 2 exhibited the highest mean biomass per unit area (89.03 Mg/ha) and vegetation carbon stock (38.87 Mg-C/ha), followed by Zone 10. Relatively low biomass and carbon stock values observed in this study can be attributed to the low diversity and abundance of mangrove species in the region. These results underscore the significant carbon storage capacity of the Dugong Conservation Reserve's mangroves and highlight the need for targeted conservation and management efforts to enhance carbon sequestration. This study also emphasises the interconnectedness of mangroves and seagrass ecosystems, which support species like dugongs, reinforcing the reserve's ecological importance.