北京山区油松的耗水规律

摘要

为了探究北京山区常绿树的耗水规律,利用大型称重式蒸渗仪于2010年对北京西山地区油松蒸腾进行连续高精度的观测,分析油松蒸腾的动态变化,同时结合气象因子的观测数据,分析蒸腾强度与气象因子的相关性,从而定量得到各因子对蒸腾的影响程度.结果表明:油松晴天蒸腾日变化呈单峰曲线趋势,在中午时刻出现最大值,与太阳辐射和气温变化趋势保持一致；阴雨天表现为多峰曲线趋势.在各气象因子中,蒸腾强度(Ti)与大气温度(Ta)、大气相对湿度(RH)、冠层净辐射(Rn)和饱和水汽压差(VPD)的相关性较好,其相关方程为Ti=2.228-0.07 Ta-0.032RH-0.002Rn+1.108VPD.%In order to explore the evapotranspiration of evergreen trees in Beijing Mountainou Area,the dynamic change of Pinus tabuliformis transpiration in the West Mountain Area of Beijing was continuously and high-precision measured in June 2010 using large-scale weighing lysimeter.Combined with the observational data of meteorological factors,the correlation between transpiration intensity and meteorological factors was analyzed.The results showed that:In sunny days,diurnal variation of transpiration of Pinus tabulaeformis showed a single-peak curve trend and the maximum was found at noon,which was in accordance with the solar radiation intensity and the temperature.But in rainy days,it showed the multi-peak curve trend.Transpiration intensity (Ti) was significantly related to atmospheric temperature (Ta),relativeair humidity (RH),canopy net radiation (Rn) and vapor pressure deficit (VPD),the regression equation was Ti =2.228-0.07Ta-0.032RH-0.002Rn + 1.108VPD.