[Effects of Mine Remediation Mode on Microbial Community Structure and Function in the Rhizosphere Soil of Robinia...

To explore the effects of soil substrates （guest soil, iron tailings sand, and dump mixed soil） on plant rhizosphere microbial diversity and function of three mine restoration modes in the northern Hebei mining area of China, the soil environment, microbial community structure, and coupling mechanism of rhizosphere soil were explored by soil nutrient determination technology and high-throughput sequencing technology. The results showed that： ① The species and distribution of bacteria and fungi in the three soil substrates were similar. There were 2 402 species of bacteria, and the dominant bacterial community was Proteobacteria. There were 1 059 species of fungi, and the dominant fungal community was Ascomycota. Among them, the similarity between the guest soil and the dump soil was the highest, with a total of 102 species of bacteria and 180 species of fungi. ② Soil substrate environmental factors in different remediation modes had significant effects. The contents of pH, SOM, and TN in guest soil were significantly higher than those of other types of soil. The combined effect of soil enzyme activity and soil nutrients had the greatest impact on the bacterial community, while the single effect of soil nutrients had the greatest impact on the fungal community. ③ There were significant differences in the structure and function of bacterial and fungal communities in different substrates. At the genus level, the bacterial and fungal community structure was significantly correlated with pH and TK （P<0.01）, and the fungal structure was significantly correlated with SUC （P<0.05）. The bacterial function of tailings sand was similar to that of the dump, which was mainly chemoheterotrophic and oxidative heterotrophic. The functions of fungi in the three groups were similar, and the main functions of different trophic types differed. The conclusions of this study have theoretical importance for the effective and sustainable development of the subsequent ecological restoration work in the mining area.