Physicochemical and microbiological assessment of soil quality on a chronosequence of a mine reclamation site

Abstract

SummaryAssessment of the activity of the soil microbial community is essential to evaluate the success of reclamation. The purpose of this study was to investigate the effect of reclamation on soil physiochemical, biological and microbial community properties. Soil samples were collected from 12 post‐mining sites with different lengths of time since reclamation (2, 3, 5, 6, 7, 9, 11, 16, 19, 21, 23 and 26 years) at Pingshuo surface coal mine, China. Our results indicated soil organic and labile carbon, nitrogen, enzyme activities, microbial functional diversity, bacterial, archaeal and fungal abundances and taxonomic diversity improved with increasing time since reclamation. Soil pH and bulk density declined with increasing time after reclamation. Redundancy analysis revealed the importance of soil pH in microbial metabolic structure and bacterial genetic assemblages, and soil organic carbon in fungal genetic assemblages. The mine soil quality index (MSQI) was positively correlated with time since reclamation, and reclamation could be considered satisfactory at the 19‐year site with an MSQI >0.5. Soil enzyme activities were strongly correlated with microbial abundance. Our overall findings indicated that nutrition, microbial abundance and functional diversity of the soil ecosystem improved after reclamation.Highlights Reclamation improved nutrition, microbial abundance and diversity in soil of a mining site. Soil enzyme activities were correlated more strongly with microbial abundance than diversity. Soil pH and SOC played important roles in bacterial and fungal genetic assemblages, respectively, with reclamation. MSQI would take about 20 years to reach a satisfactory value after reclamation.