Effects of regenerating vegetation on soil enzyme activity and microbial structure in reclaimed soils on a surface coal mine site

• Soil organic carbon pronouncedly determined both enzyme activities and microbial characteristics.
• Fungal abundance were strongly correlated with enzyme activities.
• Mixed forests were feasible scenarios in semi-arid Loess Plateau.

The aim of this study was to evaluate the influence of reclaimed scenarios on soil enzyme activities and microbial community in a reclaimed surface coal mine on the Northwest Loess Plateau of China. Soil samples were collected from a bare land (CK), and a plantation (PL) and four mixed forests (MF1-4). Soil physicochemical characteristics, four enzyme activities and microbial abundance and T-RFLP (terminal restriction fragment length polymorphism) profiles were measured. Effects of reclaimed scenarios on soil nutrients content, enzyme activities and microbial community were pronounced. Soil organic carbon could be well used to predict the major differences in enzyme activities, and microbial abundance and composition. Soil enzyme activities were more significantly correlated with fungal abundance than bacterial and archaeal ones. The higher soil nutrient content, enzyme activities, and microbial abundance and diversity were from mixed forests and the lowest ones were from CK, which suggested mixed forests would be feasible scenarios in semi-arid Loess Plateau. Soil bacteria, archaea and fungi evolved with reclaimed process, but the influences of reclaimed scenarios on each domain of microbial abundance, diversity and composition were different. These findings suggested that soil bacteria, archaea and fungi play different ecological roles during restoration process.