Altitudinal variation of soil organic carbon stock in tropical forest of Courtallam hills, Southern Western Ghats of India

The climate change and carbon mitigation through forest ecosystems play an important role in the global perspective. Soil is a huge carbon reservoir and its storage capacity varied greatly with forest type and altitude. The mountain ecosystem varies in soil organic carbon stock (SOC) due to variations in soil types, climatic conditions, vegetation patterns and elevational gradients. Soil organic carbon stockswere measured at three depths (0–10, 10–20, and 20–30 cm) in five different forest elevation (200, 400, 600, 800, and 1000 m asl) on Courtallam hills, Southern Western Ghats, India. SOC stocks increased significantly with the increase in altitude (P<0.05) at all the three layers (0–10, 10–20 and 20–30 cm). A total of SOC stocks ranged from 42.79 mg ha-1at 0–30 cm depth were observed in lower altitude (200 m) and the highest value of 50.25 mg ha-1 at 0–30 cm depth was observed in mid-elevation 600 m, while in other elevational showed 46.45, 48.49 and 45.05 mg ha-1 in 400, 800 and 1000 m respectively. SOC ranged from 17.89 to 22.37 mg ha-1 in soil surface layer (0–10 cm), 14.00 to 16.573 mg ha-1 in middle layer (10–20 cm) and 9.08 to 11.35 mg ha-1 in the bottom layer (20–30 cm). These results would also enhance our ability to assesses the role of these forest types in soil carbon sequestration and for developing and validating the SOC models for tropical forest ecosystems.