Microbial Biomass Carbon
The microbial biomass could provide a satisfactory estimate of the soil microbial population reclamation (Ross et al., 1990). MBC increased with increase in year of reclamation, similar results were reported by others (Singh et al., 2015b). Accumulation of labile carbon during reclamation promotes a rapid increase in MBC and associated soil biological activity (Mukhopadhyay et al., 2014). In this study, climate, relief and parent material were the same for all species, therefore, difference of soil properties (including soil organic carbon) found can ascribe to the increase in MBC with increase in year of reclamation.
Plant-microbe interaction and C, N cycles also play a major role in soil carbon sequestration (Macdonald et al., 2011). Microbial biomass, while a small portion of SOC, mediates the transfer of SOC among inputs, low fraction organic carbon and organo-mineral high fraction organic carbon. MBC increased in all plantations during 8 and 25 years of reclamation indicates soil redevelopment and improvement in restored coal mine soil after plantation establishment in our study. The MBC and Cstock were significantly positively correlated with the TOC (p< 0.01). This suggests with an increase in organic carbon content microbial activity also improved as organic carbon provides food and energy to microbes.