Applicability analysis for measuring evapotranspiration of Populus alba var. by sap flow and micro-lysimeter method

Using the Sap flow and Micro-lysimeter methods have measured the evapotranspiration of Populus alba var.and analyzed its applicability.The results showed that:The evapotranspiration of Populus alba var.has changed seasonally.In the growing season from May to October,the overall evapotranspiration was 508.26 mm,with the proportion of 37.1%and 62.9%for evaporation and transpiration,respectively.The tree trunk sap velocity was in good agreement with the leaf transpiration rate.It was indicated that heat pulse method can be used to measure the transpiration of Populus alba var..The relative error was within±15%compared the Sap flow and Micro-lysimeter method with the water balance method.So the Sap flow and Micro-lysimeter methods were suitable to measure the evapotranspiration of Populus alba var.