干旱区荒漠-绿洲过渡带3种典型灌木气孔导度对环境变化的响应及其对蒸腾的调控  

The Response of Stomatal Conductance of Three Typical Shrubs to Environmental Change and Stomatal Regulation of Transpiration in an Arid Desert-oasis Ecotone

作　　者：郭飞 吉喜斌 金博文 赵丽雯 赵文玥 焦丹丹 GUO Fei;JI Xibin;JIN Bowen;ZHAO Liwen;ZHAO Wenyue;JIAO Dandan(Linze Inland River Basin Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Key Laboratory of Ecohydrology and Watershed Science Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Earth Surface Processes and Resource Ecology,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,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/中国科学院生态水文与流域科学重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]北京师范大学地理科学学部/地表过程与资源生态国家重点实验室,北京100875

出　　处：《高原气象》2021年第3期632-643,共12页Plateau Meteorology

基　　金：国家自然科学基金项目(41771041)。

摘　　要：利用LI-6400XT便携式光合作用测定系统和Model 1505植物压力室对河西走廊中部荒漠-绿洲过渡带3种优势种C4植物梭梭(Haloxylon ammodendron)、沙拐枣(Calligonum mongolicum)和C3植物泡泡刺(Nitraria sphaerocarpa)的水分交换过程和叶片水势(Ψ)变化进行了观测试验,对比了荒漠植物生长季降水前后水分传输因子的变化;模拟了气孔导度对主要环境因子和叶片水势的响应;从饱和水汽压差(VPD)对气孔导度的制约作用研究了荒漠植物蒸腾的调控机制。结果表明:影响3种灌木气孔导度的主要因子依次为VPD、气温(T)和Ψ,气孔导度随着VPD和T的升高而降低,随着Ψ的降低逐渐减小;不同荒漠植物气孔导度对环境因子和叶片水势的综合响应模拟研究表明,模型能够很好地模拟气孔导度日内变化,C3植物泡泡刺对这些因子变化的响应比C4植物梭梭和沙拐枣更敏感;通过类比于欧姆定律,表明可用气孔导度和VPD的乘积来对蒸腾速率进行线性模拟,相关性很强。LI-6400XT Portable Photosynthesis System and Model 1505 Pressure Chamber were used to measure the water vapor exchange process and leaf water potential(Ψ)changes of three dominant shrub species(i. e.,C4 plant Haloxylon ammodendron,Calligonum mongolicum and C3 plant Nitraria sphaerocarpa)growing in a desert-oasis ecotone of the central Hexi Corridor. The changes of water transfer factors prior to and following rainfall events during the growing season were compared,the responses of stomatal conductance to main environmental factors and leaf water potential were quantified respectively. The regulation mechanism of stomatal conductance on transpiration of desert shrubs was also analyzed. The results showed that the main factors affecting stomatal conductance of three shrubs were vapor pressure deficit(VPD),air temperature(T)and Ψ in turn:stomatal conductance decreased with the increasing VPD and T and decreased with the decrease in Ψ. The integrated responses of stomatal conductance of these three desert plants to environmental factors and leaf water potential showed that C3 plant Nitraria sphaerocarpa was more sensitive to these factors than C4 plant Haloxylon ammodendron and Calligonum mongolicum. By analogy to Ohm’s law,the product of stomatal conductance and VPD can be used to properly simulate the transpiration rate with a linear relationship.

关 键 词：气孔导度响应 叶片蒸腾 叶片水势 气孔调控 荒漠灌木 

分 类 号：S792.119[农业科学—林木遗传育种]