Environmental controls of evapotranspiration in a mixed plantation in North China

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• 作者：Xiaojuan Tong ; Jinsong Zhang ; Ping Meng ; Jun Li…
• 关键词：Evapotranspiration ; Mixed plantation ; Eddy covariance ; Priestley–Taylor coefficient ; Decoupling factor ; Canopy conductance
• 刊名：International Journal of Biometeorology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：61
• 期：2
• 页码：227-238
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment, general; Biological and Medical Physics, Biophysics; Meteorology; Animal Physiology; Plant Physiology; Environmental Health;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-1254
• 卷排序：61

文摘

The mixed plantation plays an important role in the water cycle in the hilly area of North China. To evaluate the effect of afforestation on the water balance in this region, the temporal variation of evapotranspiration (ET) and environmental controls were investigated based on the eddy flux measurement of water vapor in a 31-year-old mixed plantation from 2006 to 2010. During 5 years, annual ET ranged from 513 to 680 mm, with an average of 579 mm. Growing season ET accounted for 72–82 % of annual ET during the 5-year period and its interannual variation was determined by the number of rainy days. In the non-growing and growing seasons, monthly ET was primarily dependent on monthly mean soil water content and monthly mean net radiation, respectively. Annual mean Priestley–Taylor coefficient (α) was 0.64, and the decoupling factor (Ω) was 0.48. High values of α and Ω implied that ET was energy limited in the growing seasons of 2006–2010. The mean annual ratio of ET to precipitation (ET/P) was 1.10. The density of the mixed plantation was around 50 % higher than the optimal value determined by local water capacity, leading to a large ET/P ratio. The dense plantation needs to be thinned to prevent excessive water loss in the hilly area of North China.