陕西渭北旱源土壤—植物—大气连续体中水分运转规律的研究──Ⅱ．生态和生理环境对植物叶水势的影响

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

在整个生长季内，研究了陕西渭北旱塬冬小麦叶水势与生态因子及叶温的关系。结果表明，冬小麦叶水势与气温呈直线正相关，与光量子通量密度呈二次曲线相关，与大气水势和相对湿度呈Ｓ型曲线相关，与土壤水势和叶温呈指数函数相关，并给出了冬小麦叶水势与各因素之间的现象学模型。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）对叶水势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水势的重要性依次为气温、大气水势、相对湿度和光量子通量密度。

For an entire season of winter wheat,effects of ecological factors and leaf temperature on leaf water potential of winter wheat on Weibei Rain fed Highland,Shaanxi Province were studied. The results showed that leaf water potential of winter wheat presented positively linear relation with air temperature(Ta) Logistic,relation with relative humidity(RH) and the water potential of water vapour in the atmosphere(a),parabolic relation with photon flux density(PFD),and exponential relation with soil water potential and leaf temperature.The phenomenological models of relationship between leaf water potential of winter wheat and ecological and physiological factors were established.The analysis of the synthetic action of main ecological factors(Ta,PFD,RH and a) on leaf water potential of winter wheat showed that on Weibei Rainfed Highland,Shaanxi Province,the importance of factors to leaf water potential was in the order of Ta,a,RH and PFD.