Analysis Of Bacterial Community Characteristics And Influencing Factors In Reclaimed Soil Of Typical Mining Species

As a black box of ecosystem,bacteria play an important role in the realization of soil’s internal functions.There are large number resources among coal,iron copper and other mines in Anhui province,mining activities for a long time to bring social and economic development at the same time,which has certain effects on the soil ecological environment system,whether the damaged land after mining,or reclaimed soil is artificial soil disturbance,when hit from the external environment condition,soil bacterial community structure and function will change.An accurate understanding of the changes of bacterial structure and function in soil disturbed by reclamation and its influencing factors can provide a basis for positive human intervention in inefficient land reclamation and promote more efficient use of reclaimed land.In this study,the reclaimed soil of two typical mines in Anhui province,coal mine and copper mine,was taken as the research object,based on the Illumina Hiseq high-throughput sequencing technology and bioinformatics analysis method,the structure and functional characteristics of bacterial community in reclaimed soil were analyzed,and the influencing factors of bacterial community structure in reclaimed soil of typical mines were revealed.The main results were as follows:(1)Proteobacteria,Acidobacteria and Actinobacteria are the main dominant bacteria in the reclaimed soil of coal mine area,among which Proteobacteria occupies dominance,accounting for up to 30%,and the proportion will change with the increase of soil depth;The diversity and richness of soil bacterial community decreased significantly with the increase of soil depth,and the diversity and richness of soil bacterial community in the 40-60 cm soil layer were significantly lower than other soil layers.There was no significant difference in microbial diversity index among different reclamation directions,Chao1 index showed woodland > grassland > arableland,and Shannon＿Wiener index showed grassland > arableland > woodland.Bacteria are involved in 68 major soil ecological functions,such as nitrification,nitrogen fixation and sulfurization.Twenty-seven species of bacteria with low relative abundance,such as Fusobacteria,Blastocatellia＿Subgroup＿4 and Mollicutes,are key groups involved in the ecological function of reclaimed soil in coal mining areas,and they play an important role in the ecological network.(2)With the increase of reclamation time,the number of soil microbial classification in copper mining area decreased.The dominant bacteria were Proteobacteria and Acidobacteria,accounting for 17.82%-52.79% and 7.13%-34.37%.There was no significant difference in soil bacterial diversity among different reclamation years.When the soil was restored to woodland after 5 years of reclamation,the Chao1 index was the highest(2544).The niche widths of bacteria in 5 years of reclamation were significantly higher than those in 7 and 9 years of reclamation,and their adaptability and competitiveness were stronger.Pedosphaeraceae and Caulobacterales were the main bacteria that caused the difference in the relative abundance of bacteria in different reclamation years and reclamation directions.The functional groups of bacteria were mainly chemoheterotrophy and aerobic chemoheterotrophy.Pedomicrobium,Bacillus and Caulobacter with low abundance may be the key groups involved in the recycling of soil materials in copper mine reclamation.It plays an important role in its ecological network.(3)The analysis of influencing factors showed that total nitrogen,organic matter,available phosphorus and available kalium were the main factors affecting soil bacterial community composition,but the response of some dominant bacteria(Proteobacteria and Actinobacteria)to factors was not obvious.It may be related to many factors such as the high complexity of soil microbial community and the particularity of gangue filling.Nitrospira and Bacilli,as functional bacteria,showed significant positive correlation with soil fertility index(P <0.05).Soil organic matter and electrical conductivity of reclaimed soil in copper mine area are the main factors affecting the changes of soil bacterial community and structure,as well as the relative abundance of functional bacteria Obscuribacteraceae and Rhodanobacter,which play a major role on soil bacterial community and functional structure.The better the soil condition,the more stable the bacterial community and functional structure.Figure [28] Table [10] Reference [129]...