塔里木河下游不同地下水埋深下胡杨水分利用来源研究  

Water utilization sources of Populus euphratica under different groundwater depths in the lower Tarim River

作　　者：蒋晓晴 郝帅 叶茂[1,2] 何定学[1,2] 张子涵 李国华 JIANG Xiaoqing;HAO Shuai;YE Mao;HE Dingxue;ZHANG Zihan;LI Guohua(College of Geographical Science and Tourism,Xinjiang Normal University,Urumqi 830054,Xinjiang,China;Xinjiang Laboratory of Lake Environment and Resources in Arid Zone,Xinjiang Normal University,Urumqi 830054,Xinjiang,China)

机构地区：[1]新疆师范大学地理科学与旅游学院,新疆乌鲁木齐830054 [2]新疆师范大学干旱区湖泊环境与资源实验室,新疆乌鲁木齐830054

出　　处：《干旱区地理》2024年第12期2017-2029,共13页Arid Land Geography

基　　金：新疆维吾尔自治区高校科研计划项目(XJEDU2022P065);新疆维吾尔自治区重点实验室招标课题(XJDX0909-2021-02);新疆维吾尔自治区自然科学基金项目(2021D01A118);国家自然科学基金项目(42161004)资助。

摘　　要：地下水和土壤水是干旱区荒漠植被生长的决定因子,荒漠植被的水分利用是干旱区生态水文过程的重要环节。为更好地了解荒漠植被对水分的利用,采用氢氧稳定同位素技术,结合贝叶斯混合模型(MixSIAR),解析不同地下水埋深下不同林龄胡杨的吸水来源。结果表明:(1)土壤水δ^(18)O和δD值随土壤深度的增加而减小,随离岸距离的增加而增大;中龄胡杨木质部水δ^(18)O和δD值变化幅度最大,老龄胡杨次之,幼龄胡杨最小;地下水δ^(18)O和δD值随离岸距离的增加而减小。(2)不同地下水埋深不同林龄胡杨的最大吸水层位均为地下水,其次为深层土壤水,靠河岸的胡杨可以直接利用河水。地下水埋深为1.98~2.10m、1.95~2.21m、2.49~2.61m、3.51~3.73m、4.66~4.73m时,老龄胡杨对地下水的利用比例分别为18.4%、19.6%、17.8%、23.1%、21.9%,中龄胡杨为16.7%、17.6%、16.7%、21.4%、21.6%,幼龄胡杨为16.0%、16.6%、19.9%(埋深2.49~2.61 m和4.66~4.73 m样地无幼苗)。(3)地下水埋深随离岸距离的增加而增大;土壤含水量和土壤盐度随离岸距离的增加而减小,随土壤深度的增加而增大;胡杨对水源的利用比例随土壤含水量和盐度的增加而增大。探究不同地下水埋深下胡杨水分利用来源,为塔里木河下游荒漠河岸林的生态恢复提供理论支撑。Groundwater and soil water are critical determinants of desert vegetation growth in arid zones,and the water utilization patterns of desert vegetation are integral to the ecohydrological processes in these regions.To enhance the understanding of water utilization by desert vegetation,this study employed the hydrogen and oxygen stable isotope tracer technique,combined with MixSIAR,to investigate the water absorption sources of Populus euphratica across different forest ages and varying groundwater burial depths.The findings revealed the following:(1)Soil water δ^(18)O and δD values decreased with increasing soil depth and increased with greater distance from the shore.Xylem water δ^(18)O and δD values exhibited the highest variability in middle-aged trees,followed by old trees and young trees.Groundwaterδ18O andδD values decreased with increasing distance from the shore.(2)The primary water source for Populus euphratica across different forest ages and groundwater burial depths was groundwater,followed by deep soil water.Populus euphratica located near the riverbank could directly utilize river water.When groundwater burial depths were 1.98-2.10 m,1.95-2.21 m,2.49-2.61 m,3.51-3.73 m,and 4.66-4.73 m,the proportion of groundwater utilization was highest in old trees,accounting for 18.4%,19.6%,17.8%,23.1%,and 21.9%,respectively.Middle-aged trees exhibited slightly lower utilization rates of 16.7%,17.6%,16.7%,21.4%,and 21.6%,while young trees showed the lowest utilization rates of 16.0%,16.6%,and 19.9%(no seedlings were observed in areas with groundwater burial depths of 2.49-2.61 m and 4.66-4.73 m).(3)Groundwater burial depth increased with distance from the riverbank,whereas soil water content and salinity decreased with distance from the riverbank and increased with soil depth.The proportion of water utilized by Populus euphratica increased with soil water content and salinity.Investigating the water utilization sources of Populus euphratica under varying groundwater burial depths provides theoretical support

关 键 词：氢氧稳定同位素 MixSIAR模型 水分来源 地下水埋深 胡杨 塔里木河下游 

分 类 号：S792.11[农业科学—林木遗传育种]