Evaluating transpiration from Pinus sylvestris var.mongolica and Caragana microphylla using sap flow method
Sap flow rates were determined using sap flow methods in August, 2006 from a 20-year-old mixed plantation of Pinus sylvestris var. mongolica and Caragana microphylla at a sandy site located in the Horqin Region of northeastern China. Sap flow rates were then used to estimate transpiration of individual trees based on their sapwood areas and leaf areas. Furthermore, the relationship between water use and soil moisture dynamics was also analyzed. The results showed that variations in transpirations of both tree species were significantly related to the changes in photosynthetically active radiation and vapor pressure deficit. The transpiration rates for P. sylvestris var. mongolica showed a declining trend over the study period, ranging from 0.21 to 1.17 mm per day with an average value of 0.81 mm per day. The transpiration from C. microphylla was relatively high and stable in semi-arid environment, and its daily transpiration values were 0.51-2.79 mm per day, with an average of 1.98 mm per day. The total transpiration from the mixed forest in August amounted to 86.5 mm, which represented 137.7% of the precipitation over the same period.
Pinus sylvestris var. mongolicaCaragana microphyllasap flow measurementstand transpirationscaling-up
国家科技期刊平台
NSTL
万方数据
维普
