陕西渭北旱源土壤—植物—大气连续作中水分运转规律的研究──Ⅲ．生态和生理环境对叶片气孔阻力的影响

STUDIES ON WATER TRANSPORTS IN THE SOIL-PLANT-ATMOSPHERE CONTINUUM ON WEIBEI RAINFED HIGHLAND, SHAANXI PROVINCE──Ⅲ.EFFECTS OF ECOLOGICAL AND PHYSIOLOGICAL FACTORS ON LEAF STOMATAL RESISTANCE

在整个生长季内，研究了陕西渭北旱源冬小麦叶气孔阻力与生态和生理因子的关系。结果表明，气孔阻力与大气温度、相对湿度和大气水势及叶温均呈二次曲线相关；与土壤水势呈直线正相关；与叶水势呈指数函数相关；当光量子通量密度小于１５２３μｍｏｌ·ｍ－２·ｓ－１时．气孔阻力与之呈幂函数相关，当光量子通量密度大于１５２３μｍｏｌ·ｍ－２·ｓ－１时，气孔阻力与之呈指数函数相关，此时气孔正处于“午休”期间。试验给出了冬小麦叶气孔阻力与各因素之间的现象模型。通过主要生态因子（气温、光量子通量密度、大气水势和相对湿度）对气孔阻力作用的综合分析表明，在陕西渭北旱塬，诸生态因子对冬小麦叶气孔阻力的重要性依次为大气水势、相对湿度、光量子通量密度和气温。并对其它影响气孔阻力的因素进行了讨论。

For an entire season of winter wheat,effects of ecological and physiological factors on leaf stomatal resistance of winter wheat on Weibei Rainfed Highland,Shaanxi Province were studied.The results showed that leaf stomatal resistance presented parabolic relation with air temperature(Ta),atmospheric relative humidity(RH),the water potential of water vapour in the atmosphere(a) and leaf temperature,positively linear relation with soil water potential,exponential relation with leaf water potential,and power function relation with photon flux density(PFD) when PFD was lower than 1523μmol.m-2·s-1 and exponential relation when PFD was more than 1523μmol. m-2·s-1 during stomatal midday depression.The phenomenological models of relationship between leaf stomatal resistance of winter wheat and ecological and physiological facters were established.The analysis of the synthetic action of main ecological factors(Ta,PFD,RH and a) on stomatal resistance showed that on Weibei Rainfed Highland,Shaanxi Province the importance of factors to leaf stomatal resistance of winter wheat was in the order of a,RH,PFD and Ta.Other factors influencing stomatal resistance were discussed.