Nitrogen uptake strategies of mature conifers in Northeastern China, illustrated by the ^(15)N natural abundance method  

作　　者：Xulun Zhou Ang Wang Erik A.Hobbie Feifei Zhu Xueyan Wang Yinghua Li Yunting Fang 

机构地区：[1]School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China [2]CAS Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110164,China [3]Key Laboratory of Stable Isotope Techniques and Applications,Shenyang 110016,Liaoning Province,China [4].4 Qingyuan Forest CERN,Shenyang 110016,China [5]Earth Systems Research Center,Morse Hall,University of New Hampshire,Durham,NH,USA [6]School of Energy and Water Resources,Shenyang Institute of Technology,Fushun 113122,China.

出　　处：《Ecological Processes》2021年第1期470-480,共11页生态过程（英文）

基　　金：funded by the National Key Research and Development Program of China(2016YFA0600802);Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDB-SSW-DQC002);K.C.Wong Education Foundation(GJTD-2018-07);Liaoning Vitalization Talents Program(XLYC1902016);the National Natural Science Foundation of China(41773094,41811530305,31901134,41571455,and 31770498);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23070103);Scientific Research Foundation of the Educational Department of Liaoning Province(L201908).

摘　　要：Background:Conifers partition different N forms from soil,including ammonium,nitrate,and dissolved organic N(DON),to sustain plant growth.Previous studies focused on inorganic N sources and specific amino acid forms using ^(15)N labelling,but knowledge of the contribution of DON to mature conifers’N uptake is still scarce.Here,we quantified the contribution of different N forms(DON vs.NH_(4)^(+)vs.NO_(3)^(−))to total N uptake,based on ^(15)N natural abundance of plant and soil available N,in four mature conifers(Pinus koraiensis,Pinus sylvestris,Picea koraiensis,and Larix olgensis).Results:DON contributed 31%,29%,28%,and 24%to total N uptake by Larix olgensis,Picea koraiensis,Pinus koraiensis,and Pinus sylvestris,respectively,whereas nitrate contributed 42 to 52%and ammonium contributed 19 to 29%of total N uptake for these four coniferous species.Conclusions:Our results suggested that all four conifers could take up a relatively large proportion of nitrate,while DON was also an important N source for the four conifers.Given that DON was the dominant N form in study soil,such uptake pattern of conifers could be an adaptive strategy for plants to compete for the limited available N sources from soil so as to promote conifer growth and maintain species coexistence.

关 键 词：Nitrogen uptake preference Organic nitrogen Inorganic nitrogen Coniferous plantation ^(15)N natural abundance Isotopic mixing model 

分 类 号：Q94[生物学—植物学]