Soil microbes play an important role in improving soil quality and enhancing carbon cycling, and consequently, are of great significance for the recovery of soil function of degraded lands. However, little is known about soil microbial properties of reconstructed ecosystems established on degraded lands. We investigated soil microbial biomass and enzyme activity for three restored tree types in post-mining lands by field sampling. The results showed that soil microbial biomass carbon increased averagely by 133.9% via planting Quercus liaotungens, Pinus tabuliformis and Rhus typhina. Invertase activity in restored site increased by 138.8% compared with that in the control site. Litter input and root exudate provided carbon sources for soil microbes during vegetation succession, and increases of soil nitrogen content and water-holding capacity were also beneficial to improve microbial growth and activity. Soil microbial biomass and invertase activity displayed significant differences due to tree species (P < 0.01), which could be explained mainly by differences in nutrition content and fine root biomass. However, soil microbial biomass and enzyme activity in restored lands were significantly lower than those in natural forests. Our results suggest that low soil microbial biomass might restrict the recovery of soil function during restoration of post-mining lands in semi-arid region.

土壤微生物在改善土壤质量和促进碳循环中起着重要作用，因此，对于恢复退化土地的土壤功能具有重要意义。然而，关于在退化土地上建立的重建生态系统的土壤微生物特性知之甚少。我们通过田间采样调查了采后土地上三种恢复树木类型的土壤微生物生物量和酶活性。结果表明，种植辽东栎，油松和鼠李的土壤微生物量碳平均增长133.9％。。恢复位点的转化酶活性比对照位点提高了138.8％。凋落物输入和根系分泌物为植被演替过程中的土壤微生物提供了碳源，土壤氮含量和持水量的增加也有利于改善微生物的生长和活性。土壤微生物量和转化酶活性因树种而存在显着差异（P  <0.01），这主要可以通过营养成分和细根生物量的差异来解释。然而，恢复土地的土壤微生物量和酶活性明显低于天然林。我们的结果表明，半干旱地区采后土地的恢复过程中，土壤微生物量低可能会限制土壤功能的恢复。