| Huainan-huaibei areas are one of the main coal production areas in China,and well mining has led to changes in the stress state of the overlying rock,forming large coal mining subsidence basins.Tension fissures are the most prevalent type of surface subsidence during the formation and stabilization of subsidence basins,running through the whole process of subsidence and widely distributed in the subsidence area.The surface tension fissures are the driving force for the change of soil quality and microbial community distribution in the sinkhole area,and it is important to identify the characteristics of soil quality and microbial community in the tension fissures area for the accurate restoration and efficient use of the sinkhole soil.In this study,we selected the coal mining tension fissure area of Suntuan mine in Huabei mining area as the study area,laid sampling lines in the longitudinal tension fissure and transverse tension fissure,set three areas from high to low in the longitudinal tension fissure area of the coal mining subsidence surface,and set four sampling points in each area.Soil samples were collected every 20 cm along the lm profile and 95 soil samples were collected in total.By testing the physical and chemical properties such as water content,organic matter,fast-acting potassium,fastacting phosphorus,total nitrogen and total phosphorus,and using high-throughput sequencing technology to determine the characteristics of bacterial communities and genetic information at different taxonomic levels,we investigated the characteristics of bacterial communities and their correlation with environmental factors in the surface tension fissure area of coal mining subsidence in Huabei mining area,and the main conclusions were as follows.(1)Distribution characteristics of environmental factors:water content,organic matter and total nitrogen are higher in the transverse tension cleavage zone than in the longitudinal tension cleavage zone,and fast-acting potassium is lower than in the longitudinal tension cleavage zone.In the vertical distribution,soil water content in the longitudinal tension rift zone is significantly clustered in the 20-80cm soil layer,and organic matter,total nitrogen and total phosphorus in the longitudinal and horizontal rift zones are significantly clustered in the surface layer,and decrease with increasing depth.Horizontally,the nutrient content of the soil in the surface layer of the longitudinal tension fissure zone shows a "reverse order" phenomenon that decreases with slope,with the most obvious distribution of total nitrogen.In the lateral fissure zone,the concentration is mainly in the middle and low parts,with the most obvious distribution of effective phosphorus,which increases as the slope decreases.(2)Study of bacterial community composition and its diversity:All soil samples yielded a total of 3649314 valid sequences,identifying a total of 42 phyla and 268 genera,with the same dominant phyla and genera in the longitudinal and transverse fissure zones and the control zone,but with differences in abundance.The phylum Actinobacteria was higher in the longitudinal fissure zone than in the transverse fissure zone,and the phylum Acidobacteria and Green Bacteria were lower than in the transverse fissure zone;the Chao1 index and Shannon index also differed,and the abundance of bacteria in the control zone was higher than in the transverse fissure zone than in the longitudinal fissure zone.Bacterial abundance was higher in the 20-40 cm soil layer in the depth direction,while bacterial abundance was lower in the subsoil.(3)Bacterial community composition,diversity and their correlation with soil environmental factors were analyzed:soil environmental factors were similarly correlated with bacterial communities in the transverse and longitudinal tensioned fissure zones.Soil organic matter,total nitrogen and phosphorus were significantly correlated with the Alpha index and were key factors influencing the abundance and relative abundance of the bacterial community.the RDA results showed that the correlation between the bacterial community and environmental factors differed between the control,horizontal and vertical tension rift zones,with the bacterial community of the surface soil being mainly influenced by total nitrogen and organic matter content at the gate level and the bacterial community of the remaining soil layers being mainly influenced by water content and The rest of the soil community was mainly affected by water content and pH.A similar phenomenon was observed at the phylum and genus level.Figure 16 Table 20 Reference 110... |
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