Water consumption of Pinus tabuliformis in Beijing Mountain Area

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.