Yin L.,UNSCO IHE Institute of Water Education |
Yin L.,Key Laboratory of Groundwater and Ecology in Arid and Semiarid Zones of China Geological Survey |
Zhou Y.,UNSCO IHE Institute of Water Education |
Huang J.,Key Laboratory of Groundwater and Ecology in Arid and Semiarid Zones of China Geological Survey |
And 8 more authors.
Environmental Earth Sciences | Year: 2014
Sap flow (SF)of a willow tree, meteorological variables, soil water content, and water table depth were measured during the growing period from mid-April to October, 2011 in the semi-arid Hailiutu River catchment, Northwest China. The measurements of SF showed diurnal fluctuations in sunny days and seasonal changes from 1.65 l/h in mid-April to 33 l/h in July. At hourly scale, SF is significantly correlated with net radiation, followed by air temperature, relative humidity, and wind speed. At daily scale, air temperature affects the dynamics of SF significantly. Daily SF correlates positively with net radiation and negatively with relative humidity. There is no correlation observed between daily SF and wind speed. The measurements of SF do not indicate water stress although the experimental period is dry. Correlation analysis shows that SF is strongly correlated with soil moisture and water table depth, indicating the willow tree uses both soil water and groundwater for transpiration. © 2013 Springer-Verlag Berlin Heidelberg.