退耕套种模式对云杉林土壤细菌群落及理化性质的影响OA北大核心

[Objective]The effect of different interplant patterns on the physicochemical properties and bacterial community of rhizos-pheric soils in Picea asperata(spruce)forests was elucidated to provide the basis for the selection of understory crops and ecological cultivation.[Method]Multiple interplant patterns were set up in P.asperata forests,comprising P.asperata+Vicia faba(CD),P.asperata+Glycine max(DD),P.asperata+Brassica rapa var.oleifera(YC),and P.asperata+Arachis hypogaea(HS),for the evalu-ations on soil physicochemical property,enzyme activity,bacterial community characteristics and their correlations.[Result]There were differences in the physicochemical indicators of rhizospheric soils in spruce forests under different interplant patterns.Soil water content(SWC),contents of total carbon(TC),total nitrogen(TN),total potassium(TK),ammonium nitrogen(NH+4-N),nitrate nitrogen(NO-3-N),available phosphorus(AP),available potassium(AK)and soil urease(URE)activity were all improved with interplantation,and the bacterial diversity under CD and DD were significantly higher than the others(P＜0.05).At the phylum level,Proteobacteria and Actinobacteria were the dominant bacterial groups under all interplant patterns.At the genus level,the relative abundances of Ellin6067 and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium were higher under CD,while those of Solirubrobacter and MND1 were relatively higher under DD,and YC had relatively high relative abundance of RB41 and Rubrobacter.In terms of soil bacterial community function,chemoheterotrophy and aerobic chemoheterotrophy accounted for the high-est proportion.Clustering of interplant patterns revealed significant differences in the soil bacterial community functions of HS,CD,DD and those of YC and CK.Correlation analysis showed that SWC,pH,TN,AP,NO-3-N had the high correlations with rhizos-pheric bacterial community under different interplant patterns,TN,NH+4-N and AP were positively correlated with the relative abundances of Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium,Ellin6067 and MND1,respectively,SWC was positively cor-related with Rubrobacter,and AK was positively correlated with Lysobacter.[Conclusion]Interplantation of different crops under spruce forests is contributed to improved soil bacterial community structure,diversifid soil bacterial community,and higher soil fer-tility.The promotive effect of different interplant patterns on soil bacterial community and physicochemical properties of spruce forest is as follows:CD＞DD＞YC＞HS＞CK.