SOIL ORGANIC CARBON CONTENT ACROSS VARIOUS GEOMORPHIC UNITS IN MANGROVE FOREST: A CASE OF DUBLAR CHAR, SUNDARBANS

ABSTRACT: Lying at the tidally active region of the Bengal Delta, the Sundarbans act as a terrestrial carbon sink and play a crucial role in climate change mitigation. However, this forest is underrepresented in term of soil organic carbon research. The purpose of this study was to investigate the Soil Organic Carbon dynamics across various geomorphic units within a small area of mangrove forest ecosystem of Dublar char of Sundarbans. Salinity and pH trends were also examined across geomorphic units to understand their interplay with soil organic carbon dynamics. Soil samples from 25 locations across various geomorphic units were collected and analyzed to determine soil organic carbon, salinity and pH levels. The Walkley-Black wet oxidation method was employed to determine the organic carbon content. Results indicate varying degree of organic carbon concentration across geomorphic units with Highland areas having high level of soil organic carbon concentrations with average concentration level of 2.05%, followed by Creeks with 1.55%. Salinity levels also varied across different geomorphic units with values ranging from 4.8 ppt to 12.7 ppt, with creek area having high level of salinity due to its close proximity to seawater. Fringe forest areas had the highest pH levels with average value of 7.4 and the lowest average pH value (6.86) was observed in Beach areas of the study area. The study holds immense significance in understanding the organic carbon dynamics of mangrove ecosystem in the Sundarbans, providing essential insights for long term climateresilient land management and biodiversity conservation efforts. 

Keyword: Geomorphology, Sundarbans, pH, salinity, soil organic carbon