Influence of anthropogenic and natural factors on the mangrove soil of Indian Sundarbans wetland

Abstract

Soil organic carbon, pH and salinity were monitored in mangrove ecosystem of Indian Sundarbans in five successive years (2006–2010). Samplings were carried out at 14 stations in four different depths (0.01-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.40 m) during premonsoon period. High organic carbon load is observed in the stations of western Indian Sundarbans (mean = 1.02 Wt %) which are near to the highly urbanized city of Kolkata. The central and eastern sectors under the protected forest area show comparatively less soil organic carbon (mean = 0.64 Wt %). A unique spatial variability in soil salinity and pH was observed with lower values in the western and eastern sectors compared to central sector. Soil pH exhibited a lower value (7.47  0.071) in reserve forest zone (central and eastern sectors) compared to western sector (7.57  0.067). The soil salinity increased with depth, while organic carbon and pH decreased with depth in all the stations. The paper depicts the increase of soil organic carbon and pH due to anthropogenic activities in western Indian Sundarbans, which if continued may decrease the potential of Sundarban soil as carbon sink and make the soil highly saline. Hence curbing of anthropogenic activities may keep the soil characteristics ecologically safe.