中文摘要：

运用热耗散法对胡杨（Populus euphratica）树干液流进行监测,同步测定部分生理特征和环境因子,并分析生长期树干液流变化特征及影响因子。结果表明：1）胡杨在生长期树干液流日变化呈现明显的昼高夜低的起伏趋势,白天液流变化呈双峰曲线,并伴有午休现象,夜间液流速率基本稳定。2）6月蒸腾和空气温度与液流率呈极显著正相关,8月则主要是由光合有效辐射和水汽压亏缺起主导作用,而10月空气相对湿度与液流率呈负相关关系,并且各影响因子与树干液流的时间滞后现象具有差异性。3）经过逐步回归,建立多元线性模型,回归方程显著。

英文摘要：

The thermal dissipation probe method was used to measure the sap flow rate of Populus euphratica,and the related environmental factors.The results showd that：（1）The sap flow rate of Populus euphratica varied regularly,with higher value in daytime than in nighttime,and more apparent fluctuation in daytime accompanied with a lunch break while the night liquid flow rate basically stable.Environmental factors on the impact of the different periods of Populus euphratica sap flow rate were different.（2）In June,transpiration and air temperature existed significant positive correlations between the sap flow rate.The diurnal variations of PAR and vapor pressure deficiency played dominant roles in August.The air relative humidity had a negative correlation with the sap flow rate in October.（3）A multiple linear equation was established by regression,and the regression was significant.