渭北旱原大官杨水分生理综合分析

由P—V技术推广得到的P—SD、P—ND曲线法在林木组织水分状况动态监测中有较大价值。主成分分析表明:渭北旱原大官杨水分关系的主要环节是组织水分状况、蒸腾耗水、土壤供水三方面,三者呈良好的线性关系。回归分析表明:影响大官杨蒸腾强度作用大小的次序是照度、气温、湿度、风速、土壤含水量。渭北旱原大官杨在7～8月耗水最大、6～7月土壤供水最差,但其在渭北旱原上仍可以良好生长。

Physiological Water Relation of P.x dakuanensis Hsu on Loess Plateau, North of Wei River

Applies P-SD and P-ND curve methods derived from P-V technique to the dynamic determiantion of water regimes in tree tissues. The principal component analysis revealed that main water relation of P.x dakuanensis on Loess Plateau, north of Wei River were water status in tree tissues, transpiration water consumption and soil water supply. Good linear relationships were found among water potential, transpiration intensity and soil water supply. Path analysis showed that order of effective enviromental factors on transpiration inetensity were irradiancy, atmospheric temperature,humidity wind speed and soil moisture content. Maximum transpiration intensity of P,x dauanensis occurs in July and August, while the soil water reaches the lowest level in June and July, these poplars can still subsist in good condition on Plateau Loess, noth of Wei River.