Soil Carbon Dynamics Under Different Ecosystems of Ooty Region in the Western Ghats Biodiversity Hotspot of India

Large-scale deforestation and increased land use change (LUC) over the past few years have shattered the ecological balance of the Western Ghats by deteriorating the soil quality and essential ecosystem services. This study was conducted in part of the Western Ghats comprising three different ecosystems, viz., agro ecosystem (AE), tea ecosystem (TE), and forest ecosystem (FE) to assess the impact of LUC on soil carbon dynamics. A total of 150 sites were chosen and soil samples were collected at three depth classes of 0-15, 15-30, and 30-45 cm to quantify the carbon pools, total organic carbon (TOC), total inorganic carbon (TIC), total carbon (TC), carbon stock, and carbon management index (CMI). The findings revealed that TOC concentration and carbon stock were significantly higher in FE than in TE and AE. On average (0-45 cm), the carbon stocks recorded in FE, TE, and AE were 77.94, 44.32, and 32.30 t ha(-1) and decreased with the depth, while the concentration of total inorganic carbon (TIC) increased with depth. Among the various carbon pools, the very labile carbon (VLC) was higher in AE and TE while the non-labile carbon (NLC) was higher in FE. The active carbon pools (AP) in AE and TE were higher than passive carbon pools (PP), whereas the reverse trend occurred in FE. The results depict the shift in carbon dynamics under different ecosystems of Ooty. The magnitude of the shift is measured by the carbon management index (CMI), which revealed a higher CMI in FE than in AE and TE. The findings thus suggest the imperative need for immediate implementation of carbon management strategies in AE and TE to improve the carbon sequestration potential, achieve land degradation neutrality and improve the carbon footprints of the Ooty.