利用热扩散式边材液流探针(TDP)对山杨树干液流的研究

Measurement of the sapwood flow of Populus davidiana with thermal dissipation sap flow proble(TDP)

利用热扩散式边材液流探针和Watch dog 小气候观测仪对延庆县上辛庄水土保持站山杨(Populusdavidiana)边材液流速率及其与环境因子的关系进行了观测研究。结果表明,山杨树干边材液流曲线呈宽峰状,表现出明显的昼夜变化和季节变化规律,日出后7:00-8:00时液流开始上升,并于13:00-16:00 时达到峰值,然后迅速下降,19:00时速度变慢,至次日日出之前液流微弱,时断时续;7 月份进入雨季,液流速率提高,8 月份由于持续干旱,有所下降,进入9月份,地形雨增加,含水量湿度提高,液流速率又重新上升,10 月份山杨生长变慢,液流速率明显下降。同时,分析了液流速率的波动规律与主要气象因素波动的相关性。

By using Thermal Dissipation Sapwood Flow Velocity Probe and Watch dog Portable-Meteorologi cal Station, the sap flow velocity of Populus davidiana and environmental factors were measured and their relationship was studied in water and soil conservation station of Yanqing Shangxinzhuang village. The results show that the sapwood flow curve of Populus davidiana take the form of wide peak, demonstrating obvious changes of day and night and seasonal variation rules. After the sunrise the sap flow velocity begins ascending at 7:00 -8:00, and reaches peak at 13:00-16:00, then drops rapidly and becomes slowl at 19:00. The sapwood flow is faint before the next sunrise, off and on. Entering rainy season in July, the sap flow velocit improves. Because of arid continuously in August, it drops to some extent. Entering September, the orographic rain increasing, water content raising by humidity, the sap flow velocit rises again. Populus davidiana growth becomes slow in October and the sap flow velocity drops obviously. At the same time, the relationship between the velocity fluctuation rules of sap flow and the main meteorological factors is analysed.