荒漠绿洲湿地水分来源及植物水分利用策略  

Water sources and strategies of plant water use in desert oasis wetland of China

作　　者：赵颖 刘冰 赵文智 温紫娟[3] 王宵 Zhao Ying;Liu Bing;Zhao Wenzhi;Wen Zijuan;Wang Xiao(Linze Inland River Basin Research Station/Key Laboratory of Ecohydrology of Inland River Basin,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;Lanzhou University,Lanzhou 730000,China)

机构地区：[1]中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院内陆河流域生态水文重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]兰州大学,甘肃兰州730000

出　　处：《中国沙漠》2022年第4期151-162,共12页Journal of Desert Research

基　　金：中国科学院A类战略性先导科技专项课题(XDA23060304);国家自然科学基金项目(41771038,42071048)。

摘　　要：水分是干旱区不同景观界面间的水分循环过程与水力联系的主体,维持着干旱区湿地生态系统的结构与功能。为量化水分来源及其对植物水分的贡献率,以河岸灌木湿地和草地盐沼湿地为研究对象,通过测定降水、径流、地下水、土壤水和植物水中δD、δ^(18)O组成,利用多源线性混合模型分析水分来源对荒漠植物水分利用的贡献率。结果表明:(1)黑河流域荒漠绿洲湿地年均降水量104.6 mm,约占蒸散量(604.47 mm)的17.03%,具有明显的季节性分布特征。地下水位与土壤含水量的波动取决于河流距离,离河道较近的河岸灌木湿地地下水深度及土壤含水量随季节波动较小,而离河道较远的草地盐沼湿地则变化很大。(2)当地大气降水线δD=6.33δ^(18)O+4.04(R2=0.931),斜率和截距均略小于全球大气降水线则符合黑河流域湿地整体降水少而蒸散量大的特点。黑河径流δD和δ^(18)O均值分别为-43.80‰±12.09‰和-8.65‰±23.33‰,地下水为-50.98‰±13.18‰和-9.74‰±25.49‰,土壤水为-42.07‰±6.89‰和-7.22‰±2.49‰,植物水为-51.84‰±14.46‰和-8.50‰±24.13‰。(3)地表蒸发是荒漠绿洲湿地土壤氢、氧同位素富集的主要原因。地下水和河水分别是草地盐沼湿地与河岸灌木湿地的主要水分来源,贡献率分别约为61%和50%,表明湿地植物相比于干旱区脉冲式降水更依赖较为稳定的水源。(4)植物根系深度和毛细根分布是决定荒漠绿洲湿地植物水分利用策略的重要因素。Water is the backbone of hydraulic connection and water cycle process between different landscape in arid area,which further maintains the structure and function of wetland ecosystem in arid area.In order to quantify water source and its contribution to plant water,this paper takes riparian shrub wetland and salt-marsh grassland wetland as research objects,by measuring theδD andδ^(18)O composition of precipitation,runoff,groundwater,soil water and plant water,to analyze the contribution rate of water sources to water use of desert plants with the linear mixed model.The results showed that:(1)annual rainfall average 104.6 mm,accounting for about 17.03%of the evapotranspiration(604.47 mm)in desert oasis wetlands in which has obvious seasonal distribution characteristics.The fluctuation of groundwater and soil water content depends on the distance from the river.The depth of groundwater and soil water content of riparian shrub wetlands near the river vary little with the seasons,while vary greatly in salt marsh grass wetlands far away from the river channel.(2)The precipitation line of local atmospheric isδD=6.33δ^(18)O+4.04(R2=0.931),and the slope and intercept are slightly smaller than the precipitation line of global atmospheric,which is consistent with the characteristics of less precipitation and large evapotranspiration in the wetlands of the Heihe River Basin.The mean values ofδD andδ^(18)O of Heihe River groundwater,runoff,soil waterand and plant water were-50.98‰±13.18‰and-9.74‰±25.49‰,-43.80‰±12.09‰and-8.65‰±23.33‰,-42.07‰±6.89‰and-7.22‰±2.49‰,-51.84‰±14.46‰and-8.50‰±24.13‰,respectively.(3)Surface evaporation is the main cause of soil hydrogen and oxygen isotope enrichment in desert oasis wetland.Runoff and groundwater were the main water sources of desert oasis wetlands,and the contribution rate of runoff to plant water use was about 50%in riparian shrub wetland,while the contribution rate of groundwater was about 61%in salt marsh grass wetland.However,precipi

关 键 词：荒漠绿洲湿地 水分来源 氢氧同位素 贡献率 水分利用策略 

分 类 号：P344[天文地球—水文科学] Q48.12[天文地球—地球物理学]