Black locust coppice stands homogenize soil diazotrophic communities by reducing soil net nitrogen mineralization  

作　　者：Kun Li Huimei Tian W.Keith Moser Steven T.Overby L.Scott Baggett Ruiqiang Ni Chuanrong Li Weixing Shen 

机构地区：[1]Mountain Tai Forest Ecosystem Research Station of State Forestry Administration,Key Laboratory of State Forestry Administration for Silviculture of the Lower Yellow River,Forestry College of Shandong Agricultural University,Tai'an,271018,Shandong,China [2]Rocky Mountain Research Station,United States Forest Service,2500 S.Pine Knoll Dr.,Flagstaff,AZ,86001,USA [3]Rocky Mountain Research Station,United States Forest Service,240 West Prospect Fort Collins,CO,80526,USA [4]Mount Tai Scenic Spot Management Committee,Tai'an,271000,Shandong,China

出　　处：《Forest Ecosystems》2022年第3期289-300,共12页森林生态系统（英文版）

基　　金：supported by the Agricultural Science and Technology Fund for Forestry Sci-tech Innovation Project of Shandong Province (No.2019LY005);the National Natural Science Foundation of China (No.31570705);Shandong Province Higher School Science and Technology Plan Project (No. J16LF09);and Shandong Province Natural Science Foundation (No. ZR2018PC006)

摘　　要：Background:Black locust(BL,Robinia pseudoacacia)is considered a promising tree species for reforestation due to its great ability to fix nitrogen.However,after two or three coppice-harvesting rotations,the productivity of BL declines.Whether soil microbial communities are affected and how these groups correlate with the nitrogen mineralization process across multi-generation stands remains unclear.Methods:We investigated the composition and structure of free-living nitrogen-fixing microorganisms(diazotrophs)by sequencing the marker gene nifH and compared these results to levels of soil nitrogen mineralization in the bulk soil and rhizosphere in black locust plantations on Mount Tai,China.Results:The results showed multi-generation BL coppice plantations decreased the total soil nitrogen(N),soil phosphorus(P),soil microbial biomass N(MBN),soil microbial biomass C(MBC),soil nitrification rate(Rn),soil ammonification rate(Ra),and net soil N mineralization rate(Rm),but significantly increased the concentration of soil NH_(4þ)-N to maintain sufficient NO_(3)^(-)N.The dominant species in bulk soil and rhizosphere changed from Rhodopseudomonas(22.62%and 15.76%),unclassified_c_Alphaproteobacteria(22.37%and 29.28%),unclassified_o_Rhizobiales(15.40%and 13.31%),Bradyrhizobium(12.00%and 11.74%)in seedling plantations to Bradyrhizobium(45.95%and 47.86%)and Rhodopseudomonas(43.56%and 41.84%)in coppice plantations,respectively.Mantel test and Redundancy analysis(RDA)revealed that Rn,Ra,and Rm were the most important factors shaping the diazotrophic communities.Conclusions:Our results suggest that the multi-generation BL coppice plantation can homogenize soil diazotrophic communities,which is mainly regulated by the available N loss caused by nitrogen mineralization.Strengthening the management technology of coppice plantations will provide more beneficial external consumption.

关 键 词：Black locust plantation nifH gene Nitrogen mineralization COPPICE Soil nutrient 

分 类 号：S792.27[农业科学—林木遗传育种]