Soil carbon development in rejuvenated Indian coal mine spoil

摘要

The impact of mine spoil on the landscape is significant, as excavated rock-debris is commonly disposedin heaps that blanket the original land surface. Spoil heaps destroy the original soil habitat releasing soil-bound carbon, which is difficult to re-estate when mining operations cease and restoration begins. Thepresent work follows the development of vegetative cover on a coalmine spoil tip in India over a period of19 years following restoration. The potential of re-vegetated the mine spoil to imbibe carbon is examinedthrough the development of above- and below-ground biomass development. It was observed that the soilorganic carbon and microbial biomass carbon (MBC) significantly increased with re-vegetation age, withabove ground biomass increasing by 23 times, and belowground biomass increased by 26 times during theperiod of study. Soil organic carbon and MBC increased by 4× and 6.6× times, respectively. The averagecalculated annual carbon budget was 8.40 T/ha/year, of which 2.14 T/ha was allocated to above groundbiomass, 0.31 T/ha to belowground biomass, 2.88 T/ha to litter mass and 1.35 T/ha was sequestered intothe soil. This work has shown that the development of biomass following the restoration of mine spoilwas significant and that considerable quantities of carbon were stored in above and below ground plantmatter, and in the soil itself. It is concluded that appropriate restoration strategies can be used to rapidlyestablish a viable, healthy and sustainable ecosystem that imbibes carbon into former mine-impacted land.