Evapotranspiration over artificially planted shrub communities in the shifting sand dune area of the Tengger Desert, north central China

Abstract

AbstractRevegetation is a common method to combat desertification in arid and semi‐arid areas worldwide. The objective of this study was to characterize the evapotranspiration (ET) of a 20‐year‐old revegetated area of the Tengger Desert. During the measurement period from 2009 to 2012, ET was measured by the eddy covariance technique. The result showed that the values for mean daily ET were 0.43, 0.39, 0.43 and 0.59 mm d−1 in 2009–2012, respectively. In the non‐growing season, the diurnal ET variation showed a normal distribution with a maximum value occurring at noon, while it showed multimodal distribution trend occurred in a dry day and a unimodal trend in a wet day with a maximum value occurring at noon in the growing season. During the 4‐year measurements, despite the large inter‐annual variation of precipitation (annual mean precipitation of 164.4 ± 33.5 mm), the water loss through ET (667.5 mm) was almost equal to rainfall (657.8 mm), and the mean of ET/P was 1.01.The annual ET amounts were 153.6, 143.3, 156.2 and 214.4 mm y−1 in 2009–2012, respectively, with corresponding ratio between accumulated ET and precipitation (ET/P) of 1.03, 1.14, 0.82 and 1.12. This indicated that the annual ET amounts can be modified by the soil water storage, which led to water loss through ET exceeding the water input by precipitation in a drier year, and soil water can be replenished in a wetter year. Thus, the vegetation protection system using plantations of xerophyte shrubs in the present study area is a success with a trade‐off of acceptable hydrological consequences that deserve to be popularized. Copyright © 2015 John Wiley & Sons, Ltd.