黄土高原苹果树叶片气孔导度的环境响应与模拟  

Environmental response and modeling of stomatal conductance of apple trees on the Loess Plateau

作　　者：苗玉 高冠龙[1,2,3] 李伟 MIAO Yu;GAO Guanlong;LI Wei(College of Environment and Resource,Shanxi University,Taiyuan 030006,Shanxi,China;Shaanxi Key Laboratory of Land Consolidation,Chang’an University,Xi’an 710064,Shaanxi,China;Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China)

机构地区：[1]山西大学环境与资源学院,山西太原030006 [2]陕西省土地整治重点实验室,陕西西安710064 [3]中国科学院西北生态环境资源研究院,甘肃兰州730000

出　　处：《干旱区地理》2021年第2期525-533,共9页Arid Land Geography

基　　金：山西省应用基础研究面上青年基金项目(201801D221286);中国博士后科学基金资助项目(2018M643769);山西省高等学校科技创新项目(2020L0028);中央高校基本科研业务费(自然科学类)资助项目(300102279505)资助。

摘　　要：气孔导度(g_(s))是衡量植物与外界环境中水、CO_(2)等物质交换速率的重要参数,其观测与模拟可以有效指示物质交换情况及各项生理参数。通过LI-6400便携式光合测定仪对黄土高原苹果树叶片各项生理参数进行观测,分析g_(s)日变化特征及其与环境因子的响应关系,运用Jarvis模型和Ball-Woodrow-Berry(BWB)模型对g_(s)进行模拟。研究结果显示:(1)黄土高原苹果树g_(s)日变化在气温较高、辐射较强的8、9月观测日内呈双峰曲线。上午(8:00—12:00)随着太阳辐射逐渐增强,气孔张开,g_(s)在11:00—13:00出现第一次峰值;中午(12:00—14:00)由于气温(Ta)升高,为避免细胞散失过多水分,气孔关闭出现短暂的“光合午休”现象;午后(14:00—18:00),随着Ta、光合有效辐射(PAR)下降,g_(s)逐渐增加并在15:00—17:00出现第二次峰值。(2)通过灰色关联度分析,发现g_(s)与各环境因子的关联程度依次为:PAR(0.731)>CO_(2)浓度(C_(a),0.712)>饱和水汽压差(VPD,0.702)>T_(a)(0.689)>相对湿度(hs,0.673)。g_(s)与各环境因子的响应关系表现为:随PAR、T_(a)、C_(a)、h_(s)的增大而增大,随VPD的增大而减小。(3)从g_(s)的模拟结果可以看出,Jarvis模型的决定系数(0.678)、修正效率系数(0.335)和修正一致系数(0.803)均优于BWB模型各值(0.329、-1.630、0.138),而平均绝对误差(0.103)小于BWB模型(0.143),表明Jarvis模型模拟效果较好。通过对黄土高原苹果树叶片g_(s)环境响应与模拟的分析研究,对于掌握苹果树叶片一天内不同时刻对水分的需求变化,进一步提高该地区苹果树种植的水资源利用效率具有重要意义。In this study,stomatal conductance(g_(s))was used to measure the exchange rate of water,CO_(2),and other substances between plants and the external environment.The observation and simulation of g_(s) effectively indicated the exchange of substances and various physiological parameters.The Loess Plateau is typical of a temperate monsoon climatic zone in China and supports an agricultural area dominated by the cultivation of apple trees.In this study,an LI-6400 portable photosynthesis system was used to observe the physiological parameters of apple trees in situ on the Loess Plateau,the diurnal variation characteristics of their g_(s),and the relationships of these variables with environmental factors.The g_(s) was simulated using the Jarvis model and the Ball-Woodrow-Berry(BWB)model.The results show that(1)the diurnal variation of g_(s) in apple trees on the Loess Plateau showed a bimodal curve in August and September when temperatures were high and radiation was strong.The solar radiation increased gradually in the morning_(s)(8:00—12:00),the stomata opened,and the first peak of g_(s) appeared between 11:00 and 13:00.Around the noon hour(12:00—14:00),stimulated by the increase in temperature(T_(a)),the stomata of plants closed for a short period during the“midday depression of photosynthesis”to reduce water loss from plant cells.In the afternoon(14:00—18:00),as T_(a) and photosynthetically-active radiation(PAR)decreased,g_(s) gradually increased,and a second peak appeared between 15:00 and 17:00.(2)Using the gray correlation degree,the correlation between g_(s) and various environmental factors was as follows(in descending order):(PAR,0.731)>CO_(2) concentration(C_(a),0.712)>vapor pressure deficit(VPD,0.702)>T_(a)(0.689)>relative humidity(hs,0.673).The response relationship between g_(s) and the various environmental factors produced the following results:(1)it increased with increases in PAR,T_(a),C_(a),and hs and decreased with increases in VPD,and(2)The simulation of g_(s) showed that the value of th

关 键 词：气孔导度 灰色关联度 苹果树 黄土高原 

分 类 号：S661.1[农业科学—果树学]