Carbon Sequestration in Revegetated Coal Mine Soil: A Chronosequence Study in the Gevra Opencast Project, Chhattisgarh, India

Abstract

Coal, contributing to over 70% of India’s energy production, is intrinsically linked to significant land degradation, notably from mining operations. One of the adverse effects of coal mining is the greenhouse gas emissions from coal combustion, fallen biomass, and mineralization of exposed soil organic matter (SOM). This degradation often results in a significant reduction of SOM content in disturbed soils, which can potentially be countered by targeted soil restoration and strategic revegetation. This study, based in Gevra Coal Mines, Chhattisgarh, probes into the intricacies of soil carbon (SOC) sequestration, focusing on the roles played by plant litter quality and decomposition rates. Through the analysis of different carbon parameters from soil samples collected under the three native plant species - Azadirachta indica, Dalbergia sissoo, and Gmelina arborea, the research underscores that litter quality, more than quantity, is pivotal to effective carbon sequestration. As vegetation gets restored, a resistant SOC pool accumulates, which further contributes to long-term SOC sequestration. With time, SOC molecules undergo humification, becoming more aromatic and stable. The molecular properties of these molecules play a critical role in defining soil quality in reclaimed areas. Spectroscopic methodologies, such as FT-IR and UV-vis, emerged as valuable tools to discern SOC molecular attributes and their dynamics. Of the tree species studied, D. sissoo demonstrated superiority in both quality and quantity of sequestered carbon. In conclusion, the research reaffirms the indispensable need for robust afforestation measures in coal mining areas. As vegetation gets restored, not only is carbon effectively sequestered, but soil health is gradually revived, emphasizing the role of strategic revegetation in post-mining landscapes. © 2025 John Wiley & Sons Ltd.