Water use characteristics of different pioneer shrubs at different ages in western Chinese Loess Plateau:Evidence from δ^(2)H offset correction  

作　　者：ZHANG Yu ZHANG Mingjun QU Deye WANG Shengjie Athanassios A ARGIRIOU WANG Jiaxin YANG Ye 

机构地区：[1]College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China [2]Key Laboratory of Resource Environment and Sustainable Development of Oasis,Gansu Province,Northwest Normal University,Lanzhou 730070,China [3]Laboratory of Atmospheric Physics,Department of Physics,University of Patras,GR-26500 Patras,Greece

出　　处：《Journal of Arid Land》2022年第6期653-672,共20页干旱区科学（英文版）

基　　金：This study was funded by the National Natural Science Foundation of China(41771035,42071047);the Foundation for Distinguished Young Scholars of Gansu Province(20JR10RA112);the Northwest Normal University(NWNU-LKZD2021-04);the Department of Education of Gansu Province:"Innovation Star"Program of Excellent Postgraduates(2021CXZX-217).

摘　　要：Caragana korshinskii Kom.and Tamarix ramosissima Ledeb.are pioneer shrubs for water and soil conservation,and for windbreak and sand fixation in arid and semi-arid areas.Understanding the water use characteristics of different pioneer shrubs at different ages is of great importance for their survival when extreme rainfall occurs.In recent years,the stable isotope tracing technique has been used in exploring the water use strategies of plants.However,the widespreadδ^(2)H offsets of stem water from its potential sources result in conflicting interpretations of water utilization of plants in arid and semi-arid areas.In this study,we used three sets of hydrogen and oxygen stable isotope data(δ^(2)H andδ^(18)O,correctedδ^(2)H_c1 based on SW-excess andδ^(18)O,and correctedδ^(2)H_c2 based on−8.1‰andδ^(18)O)as inputs for the MixSIAR model to explore the water use characteristics of C.korshinskii and T.ramosissima at different ages and in response to rainfall.The results showed thatδ^(2)H_c1 andδ^(18)O have the best performance,and the contribution rate of deep soil water was underestimated because ofδ^(2)H offset.During the dry periods,C.korshinskii and T.ramosissima at different ages both obtained mostly water from deeper soil layers.After rainfall,the proportions of surface(0-10 cm)and shallow(10-40 cm)soil water for C.korshinskii and T.ramosissima at different ages both increased.Nevertheless,there were different response mechanisms of these two plants for rainfall.In addition,C.korshinskii absorbed various potential water sources,while T.ramosissima only used deep water.These flexible water use characteristics of C.korshinskii and T.ramosissima might facilitate the coexistence of plants once extreme rainfall occurs.Thus,reasonable allocation of different plants may be a good vegetation restoration program in western Chinese Loess Plateau.

关 键 词：stable isotope Caragana korshinskii Tamarix ramosissima water uptake pattern isotope depletion 

分 类 号：Q948[生物学—植物学]