Changes in Transpiration and Evapotranspiration of Grapevines (Vitis vinifera L.) in Arid Oasis in Northwestern China

Abstract

【Objective】 The ratio of transpiration (T) to evapotranspiration (ET) varies with plants and their growth stages. The aim of this paper is to experimentally study T and ET, as well as their temporal variations. 【Method】 The experiment was conducted at a grapevine vineyard in an arid oasis in northwestern China. The transpiration and evapotranspiration of the grapevines (Vitis vinifera L.) were measured using sap-flow sensor, microclimatic station and eddy-covariance methods, respectively, at different growth stages. 【Result】 During the whole growth season, the transpiration increased from the initial 0.20 mm/d to 8.13 mm/d at the middle of growth season; it then dropped gradually to 3.32 mm/d when the leaves started falling. In comparison, the associated evapotranspiration increased from initial 0.44 mm/d to 9.97 mm/d before gradually decreasing to 4.91 mm/d. The average T/ET ratio was approximately 63.5%. 【Conclusion】 Transpiration is the dominant soil water loss during the growth season of the grapevines (Vitis vinifera L.) in arid oasis in northwestern China.

Keywords

• arid oasis area
• vitis vinifera l.
• sap flow
• eddy covariance
• transpiration-evapotranspiration ratio