Response of Soil Microbial Diversity and Community Structure to Erosion-Deposition in Slope Farmland in Typical Black Soil Area of Northeast China
[Objective]The black soil region of Northeast China is an important commodity grain production base in China.However,intense soil erosion has led to a decline in soil health and ecological functions in the region.[Method]The microbial diversity of soils at different slope positions and their relationship with the co-occurrence network was analyzed using slope farmland soils from typical black soil areas,and the effects of erosion-deposition on soil microbial communities were investigated in combination with soil physicochemical properties.[Result]The results showed that:(ⅰ)Soil erosion significantly reduced microbial α-diversity while deposition increased it.Soil organic carbon(SOC)and mean weight diameter(MWD)had a significant positive correlation with microbial diversity.(ⅱ)Erosion-deposition did not change the major dominant groups at the phylum or family levels of bacterial and fungal.However,at the phylum and family level,changes in the relative abundance of the main dominant groups at the fungal were more pronounced than in the case of bacteria.(ⅲ)The results of redundancy analyses indicated that erosion-deposition,by altering SOC,total phosphorus(TP),MWD,etc.,led to different trends in the relative abundance of species significantly affected by them.(ⅳ)Soil erosion significantly reduced the complexity of the bacterial co-occurrence network,whose node and edge respectively decreased from 540 and 572(top of slope)to 488 and 520(lower slope)and increased to 546 and 602(foot of slope).Also,soil erosion significantly increased the number of clustering coefficients,the number of which increased from 0.38(top of the slope)to 0.41(lower slope).Meanwhile,erosion-deposition significantly changed the number of nodes of the fungal network,the number of which decreased from 223(foot of slope)to 187(lower slope)and increased to 201(foot of slope).In addition,the bacterial network stability showed a decreasing trend with increasing erosion intensity while the fungal network stability showed a decreasing and then increasing trend.[Conclusion]This study revealed the changes and driving factors of soil microbial diversity and community structure under erosion-depositions and provided a theoretical basis for further understanding of the interaction between soil physicochemical properties and microbes in slope farmland of typical black soil area.
Black soil regionSlope farmlandMicrobial communitySoil erosionCo-occurrence network
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