柽柳(Tamarix chinensis)气孔导度对环境因子的响应特征和模拟  

Stomatal conductance characteristics and simulation of Tamarix chinensis

作　　者：李端 任孝宗 王佩将 Li Duan;Ren Xiaozong;Wang Peijiang(Department of Geographical Sciences/Shanxi Key Laboratory of Earth Surface Processes and Resource Ecology Security in Fenhe River Basin,Taiyuan Normal University,Jinzhong 030619,Shanxi,China)

机构地区：[1]太原师范学院地理科学学院/汾河流域地表过程与资源生态安全山西省重点实验室,山西晋中030619

出　　处：《中国沙漠》2024年第5期195-204,共10页Journal of Desert Research

基　　金：山西省高等学校科技创新项目(2022L414);山西省基础研究计划(自由探索类)项目(202303021212257,202403021211205);山西省哲学社会科学规划课题(2023YY228,2023YY226)。

摘　　要：进行叶片尺度气孔行为特征、对水分利用的影响及对环境因子的响应研究,并进行叶片气孔导度的模拟,对于理解区域植被和生态系统对环境的适应机制和进行水资源管理具有重要意义。采用LI-COR6400光合作用测定系统,对柽柳(Tamarix chinensis)各项光合生理特征进行野外观测,分析了柽柳叶片气孔导度(G_(s))对环境因子的响应特征。结果表明:(1)大气相对湿度(h_(s))、光合有效辐射(PAR)和空气温度(T_(a))对柽柳叶片G_(s)影响较大,与G_(s)的相关性h_(s)(0.662)>PAR(0.613)>T_(a)(0.601)。(2)柽柳叶片G_(s)日变化趋势为先升高后降低。06:00开始,随着PAR增强和T_(a)升高,G_(s)升高,随后PAR减弱和T_(a)降低,G_(s)降低。6、7月正午T_(a)过高引起叶片气孔闭合,G_(s)最大值出现在10:00左右;8、9月G_(s)最大值出现在14:00左右。(3)在生长季末期,柽柳能够通过G_(s)的调节,实现对水分的高效利用来适应干旱的环境。(4)用经验模型(Jarvis)、半经验模型(BWB)和气孔导度机理模型(USO)模拟G_(s),模拟结果的决定系数(R^(2))、修正效率系数(MEC)和均方根误差(RMSE)分别是(0.713、0.409、0.024)、(0.482、0.309、0.158)和(0.260、0.135、0.255)。在3个模型中,Jarvis模拟R^(2)和MEC值最大且RMSE值最小,说明其模拟精度最高。Research on stomatal behavior characteristics,influence on water use and response to environmental factors at blade scale,and stomatal conductance of the simulation,to understand the regional mechanism of vegetation and the ecological system to adapt to the environment and water resources management is of great significance.In this study,the photosynthetic physiological characteristics of Tamarix chinensis were observed by the LI-COR 6400 photosynthesis measurement system in the field,and the characteristics,influence,and response to environmental factors of stomatal conductance (G_(s)) of Tamarix chinensis leaves were analyzed.The results showed that:(1) Atmospheric relative humidity (h_(s)),photosynthetically active radiation (PAR) and air temperature (T_(a)) had significant effects on G_(s),and the correlation between the three environmental factors and leaves G_(s)was ranked as h_(s) (0.662)>PAR (0.613)>T_(a) (0.601) in descending order.(2) The diurnal variation trend of leaf G_(s) of Tamarix chinensis increased at first and then decreased.At 06:00,G_(s) increased with PAR enhancement and T_(a) increase,then PAR weakened and T_(a) decreased,then G_(s) decreased.Due to the high midday T_(a) in June and July,stomatal closure of leaves was caused,and the maximum G_(s) value appeared at around 10:00 in June and July,and around 14:00 in August and September.(3) At the end of the growing season,Tamarix chinensis could adapt to the arid environment by increasing WUE by regulating G_(s) to achieve efficient water use.(4) By using three different models:an experience model (Jarvis),a semi-empirical model (BWB),and the mechanism of stomatal conductance model (USO) to simulate G_(s),the determination coefficient (R^(2)),the modified efficiency coefficient (MEC) and the root mean square error (RMSE) of the simulation results were (0.713,0.409,0.024),(0.482,0.309,0.158) and (0.260,0.135,0.255),respectively.Among the three models,the results of the Jarvis model simulation were obtained with the highest R^(2) and MEC values

关 键 词：柽柳(Tamarix chinensis) 气孔导度 Jarvis模型 BWB模型 USO模型 

分 类 号：Q945.1[生物学—植物学]