Long-time precipitation reduction and nitrogen deposition increase alter soil nitrogen dynamic by influencing soil bacterial communities and functional groups  

作　　者：Guoyong YAN Yajuan XING Shijie HAN Junhui ZHANG Qinggui WANG Changcheng MU 

机构地区：[1]School of Forestry,Northeast Forestry University,Harbin 150040,China [2]College of Agricultural Resource and Environment,Heilongjiang University,Harbin 150080,China [3]College of Life Sciences,Henan University,Kaifeng 475004,China [4]institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Pedosphere》2020年第3期363-377,共15页土壤圈（英文版）

基　　金：This research was part of the project Global Change and Response which is supported by the National Key Research and Development Program of China(No.2016YFA0600800)and the National Natural Science Foundation of China(Nos.41773075,41575137,31370494,and 31170421).

摘　　要：The effects of precipitation reduction and nitrogen deposition increase on soil bacterial communities and functions impact soil nitrogen cycling. Seasonal changes could modify the effects of precipitation reduction and nitrogen deposition increase on bacterial communities and functions by changing soil environments and properties. Understanding soil microbial communities and the seasonal response of functions to precipitation reduction and nitrogen deposition increase may be important for the accurate prediction of changes in the soil nitrogen dynamics. Thus, a long-term field simulation experiment of nitrogen deposition increase and throughfall exclusion was established to investigate soil bacterial communities’ response to nitrogen deposition increase and/or precipitation reduction, with no nitrogen deposition increase and no precipation reduction as a control, in a temperate forest. We examined soil bacterial communities(Illumina sequencing) under different treatments during the winter, freezing-thawing cycle periods(FTCs), and growing season. The bacterial functional groups were predicted by the FAPROTAX database. The results showed that nitrogen deposition increase, precipitation reduction, the combined effect of nitrogen deposition increase and precipitation reduction, and seasonal changes significantly altered the soil bacterial community composition.Interestingly, by combining the result of a previous study in which nitrogen deposition increase increased the nitrous oxide flux in the same experimental system, the loss of soil nitrogen was increased by the decrease in denitrification and increase of nitrification bacteria under nitrogen deposition increase,while ammonification bacteria significantly increased and N-fixing bacteria significantly decreased with precipitation reduction compared to the control. In relation to seasonal changes, the aromatic-degrading, cellulolytic, and ureolytic bacteria were lowest during FTCs, which indicated that FTCs might inhibit biodegradation. Nitrification and nitrite

关 键 词：copiotrophic bacteria DENITRIFICATION multidimensional effect NITRIFICATION oligotrophic bacteria seasonal changes soil acidification water stress 

分 类 号：S154.3[农业科学—土壤学]