柴达木盆地荒漠灌木水分利用效率及其影响因素  

Water use efficiency of desert shrub in Qaidam basin and its influencing factors

作　　者：赵昀浩 孙红艳 陈辉[1] 杨帆[1] ZHAO Yunhao;SUN Hongyan;CHEN Hui;YANG Fan(Hebei Technology Innovation Center for Remote Sensing Identification of Environmental Change,Hebei Key Laboratory of Environmental Change and Ecological Construction,School of Geographical Sciences,Hebei Normal University,Shijiazhuang 050024,China)

机构地区：[1]河北师范大学地理科学学院,河北省环境演变与生态建设实验室,河北省环境变化遥感识别技术创新中心,石家庄050024

出　　处：《生态学报》2025年第6期2605-2620,共16页Acta Ecologica Sinica

基　　金：河北省自然科学基金面上项目(D2023205005);国家自然科学基金面上项目(40971118)。

摘　　要：干旱地区植物在节约用水和抵御干旱方面具有独特的生理响应机制,成为干旱地区植物维持生存和生长发育的关键因素。然而,在高海拔荒漠地区,植物水分利用效率沿干旱梯度的变化趋势及其与植物生理生态因子和环境因子的关系尚不清楚。本文以柴达木盆地东部格尔木、诺木洪、大柴旦、德令哈和都兰地区9种典型荒漠灌木为研究对象,采用气体交换法测定不同植物的瞬时水分利用效率和内禀水分利用效率,并用δ^(13)C值表示植物长期水分利用效率,通过皮尔逊相关分析、冗余分析等方法研究水分利用效率对植物生理生态因子和环境因子的响应特征。结果表明:植物群落和物种尺度δ^(13)C与瞬时水分利用效率和内禀水分利用效率均呈极显著正相关关系(P<0.05),水分利用效率随干旱程度增加总体呈增加趋势。不同物种间水分利用效率存在显著差异,沙拐枣作为C_(4)物种,其长期、瞬时和内禀水分利用效率均高于其他C_(3)物种;植物生理生态因素对水分利用效率的影响强于土壤理化性质和气候因素,植物生理生态因素、土壤、气候因素分别解释了91.14%、35.64%、39.68%水分利用效率的总体变异,其中胞间二氧化碳浓度、净光合速率和土壤全磷对水分利用效率的影响最大,解释率分别为15%、10.8%和8.3%。研究结果对认识高海拔荒漠区典型荒漠植物水分利用效率特征及其生理生态机制具有重要意义。Plants in arid regions possess unique physiological mechanisms to conserve water and resist drought,which are crucial for their survival and growth.However,the trend of WUE along the drought gradient and its relationships with plant physiological and ecological factors and environmental factors in high-altitude desert areas remain unclear.In this study,we selected nine typical shrubs from Golmud,Nomuhong,Da Qaidam,Delhi,and Dulan as research subjects,measured the instantaneous and intrinsic water use efficiency of different plants using the gas exchange method,and used theδ^(13)C value to represent the long-term water use efficiency of plants.We analyzed the response characteristics of water use efficiency to plant physiological and ecological factors and environmental factors using Pearson correlation analysis and redundancy analysis.The results showed that both instantaneous and intrinsic water use efficiency were significantly positively correlated withδ^(13)C at both community and species scales(P<0.05).Water use efficiency showed an overall increasing trend with the increase of drought degree.There are significant differences in water use efficiency between different species,and Calligonum korlaense,as a C_(4) species,its long-term,instantaneous and intrinsic water use efficiency were higher than other C_(3) species.The influence of plant physiological and ecological factors on water use efficiency is stronger than that of soil physical and chemical properties and climate factors,which explained 91.14%,35.64%,and 39.68%of the overall variation in water use efficiency,respectively.Among them,the intercellular CO2 concentration(Ci),leaf net photosynthetic rate(A)and soil total phosphorus(STP)have the greatest influence on water use efficiency,with explanatory power of 15%,10.8%,and 8.3%,respectively.The results are of great significance for understanding the characteristics and physiological and ecological mechanisms of water use efficiency of typical desert plants in high altitude desert areas.

关 键 词：柴达木盆地 荒漠灌木 水分利用效率 影响机制 

分 类 号：Q94[生物学—植物学]