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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。
The thermal dissipation method was used to monitor the sap flow in Populus euphratica. Some physiological characteristics and environmental factors were simultaneously measured. The characteristics of flow and the influencing factors during the growth period were analyzed. The results showed that: 1) Populus euphratica diurnal variation of trunk flow in the growing season showed a clear day-night high and low fluctuation trend. During the daytime, the change of flow showed a bimodal curve with noon-break, and the flow rate was basically stable at night. 2) There was a significant positive correlation between transpiration and air temperature in June and liquid flow rate. In August, the dominant effect was mainly caused by photosynthetically active radiation and water vapor pressure deficit. In October, relative humidity and air flow rate were negatively correlated , And the time lag between each influencing factor and the sap flow is different. 3) After stepwise regression, a multiple linear model was established and the regression equation was significant.