Detecting Soil Microbial Diversity Changes in the Reclaimed Land for Soil Rehabilitation in Antaibao Opencast Coal Mine, China.

Understanding soil microbe changes during land reclamation is crucial for reusing damaged land resources. In the past 20 years, the Antaibao opencast mine, located in Shanxi Province, China, has adopted a variety of reclamation patterns to restore the damaged soil. Although considerable research has been done on soil reclamation and vegetation restoration, reasonable reclamation patterns selection and the representative indicator reflecting the restoration condition of reclaimed soil microbe biodiversity are still absent to date. This study evaluates the reclamation effect of different reclamation time and patterns. The representative indicator describing soil microbe diversity changes is then screened from soil physical, chemical, and biological indicators. The main results and conclusions are in the following. Firstly, the land reclamation time and patterns have great effects on soil microbial activity, irregularity, abundance, and the utilization of different carbon sources. The soil microbial diversity increases with the reclamation periods under the same reclamation pattern and the diversity is mainly affected by the reclamation patterns under the same reclamation time. Secondly, when the plant grows normally, the greatest single plant reclamation pattern is caragana, followed by chinese pine, buckthorn, and locust. The configuration optimization sequence of mixed forest is buckthorn×locust, caragana×locust, buckthorn×apricot×wolfberry. Plant competition and vegetation degradation greatly affect the soil microbial diversity. Finally, we analyze and verify the relationship between biodiversity index and soil physical properties (pH and soil water content), chemical properties (soil organic matter, total nitrogen, total phosphorus, available phosphorus, total potassium, and available potassium), and biological indicators (ergosterol). The results shows that the content of ergosterol is consistent with soil microbial activity, irregularity, and abundance. So ergosterol can be used as one representative biodiversity indicator. These findings can contribute to better determining reasonable reclamation models and support for soil rehabilitation in reclaimed open cast coal mines.