Stable oxygen-hydrogen isotopes reveal water use strategies of Tamarix taklamakanensis in the Taklimakan Desert, China  

作　　者：DONG Zhengwu LI Shengyu ZHAO Ying LEI Jiaqiang WANG Yongdong LICongjuan 

机构地区：[1]Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China [2]College of Resources and Environment Science,Xinjiang University,Urumqi 830046,China [3]College of Life Science,Xinjiang Normal University,Urumqi 830054,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]College of Resources and Environmental Engineering,Ludong University,Yantai 264025,China

出　　处：《Journal of Arid Land》2020年第1期115-129,共15页干旱区科学（英文版）

基　　金：supported by the "Research and Development of Sand Prevention Technology of Highway and Soil Erosion Control Technology of Pipelines" of the Strategic Priority Research Program of the Chinese Academy of Sciences "Environmental Changes and Silk Road Civilization in Pan-Third Pole Region"(XDA2003020201);the Key Inter-governmental Projects for International Scientific and Technological Innovation Cooperation of the National Key Research and Development Program of China:"China-Mongolia Cooperation Research and Demonstration in Grassland Desertification Control Technology"(2017YFE0109200);the National Natural Science Foundation of China(41571011,31971731,U1703102);the Key Technical Personnel(Y932111);the Thousand Youth Talents Plan Project(Y472241001)

摘　　要：Tamarix taklamakanensis,a dominant species in the Taklimakan Desert of China,plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability.This study aimed to determine the water use strategies of T.taklamakanensis in the Taklimakan Desert under a falling groundwater depth.Four typical T.taklamakanensis nabkha habitats(sandy desert of Tazhong site,saline desert-alluvial plain of Qiemo site,desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site)were selected with different climate,soil,groundwater and plant cover conditions.Stable isotope values of hydrogen and oxygen were measured for plant xylem water,soil water(soil depths within 0–500 cm),snowmelt water and groundwater in the different habitats.Four potential water sources for T.taklamakanensis,defined as shallow,middle and deep soil water,as well as groundwater,were investigated using a Bayesian isotope mixing model.It was found that groundwater in the Taklimakan Desert was not completely recharged by precipitation,but through the river runoff from snowmelt water in the nearby mountain ranges.The surface soil water content was quickly depleted by strong evaporation,groundwater depth was relatively shallow and the height of T.taklamakanensis nabkha was relatively low,thus T.taklamakanensis primarily utilized the middle(23%±1%)and deep(31%±5%)soil water and groundwater(36%±2%)within the sandy desert habitat.T.taklamakanensis mainly used the deep soil water(55%±4%)and a small amount of groundwater(25%±2%)within the saline desert-alluvial plain habitat,where the soil water content was relatively high and the groundwater depth was shallow.In contrast,within the desert-oasis ecotone in the Qira and Aral sites,T.taklamakanensis primarily utilized the deep soil water(35%±1%and 38%±2%,respectively)and may also use groundwater because the height of T.taklamakanensis nabkha was relatively high in these habitats and the soil water content was relatively low,which is associated with the reduced groundwater depth due Tamarix taklamakanensis, a dominant species in the Taklimakan Desert of China, plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem stability. This study aimed to determine the water use strategies of T. taklamakanensis in the Taklimakan Desert under a falling groundwater depth. Four typical T. taklamakanensis nabkha habitats(sandy desert of Tazhong site, saline desert-alluvial plain of Qiemo site, desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site) were selected with different climate, soil, groundwater and plant cover conditions. Stable isotope values of hydrogen and oxygen were measured for plant xylem water, soil water(soil depths within 0–500 cm), snowmelt water and groundwater in the different habitats. Four potential water sources for T. taklamakanensis, defined as shallow, middle and deep soil water, as well as groundwater, were investigated using a Bayesian isotope mixing model. It was found that groundwater in the Taklimakan Desert was not completely recharged by precipitation, but through the river runoff from snowmelt water in the nearby mountain ranges. The surface soil water content was quickly depleted by strong evaporation, groundwater depth was relatively shallow and the height of T. taklamakanensis nabkha was relatively low, thus T. taklamakanensis primarily utilized the middle(23%±1%) and deep(31%±5%) soil water and groundwater(36%±2%) within the sandy desert habitat. T. taklamakanensis mainly used the deep soil water(55%±4%) and a small amount of groundwater(25%±2%) within the saline desert-alluvial plain habitat, where the soil water content was relatively high and the groundwater depth was shallow. In contrast, within the desert-oasis ecotone in the Qira and Aral sites, T. taklamakanensis primarily utilized the deep soil water(35%±1% and 38%±2%, respectively) and may also use groundwater because the height of T. taklamakanensis nabkha was relatively high in these habitats and the soil water content was relatively low, which is associ

关 键 词：Tamarix taklamakanensis water use strategies stable isotopes Bayesian isotope mixing model deep soil water GROUNDWATER Taklimakan Desert 

分 类 号：Q948[生物学—植物学]