Effects of Salix psammophila on groundwater recharge in a semiarid area of north China

Abstract

Study regionThe semiarid Mu Us Sandy Land (MUSL) was selected for this study. It is in the farming‐pastoral ecotone of north China and functions as an eco-environmental barrier. Study focusAfforestation can mitigate desertification and soil erosion by improving hydrologic condition, which is particularly true for semiarid and arid regions. However, little is known about the quantitative response of hydrologic improvement to afforestation level that can be measured by leaf area index (LAI). The objective was to setup and use a physically-based model to quantitatively assess the dynamics of water fluxes from Salix psammophila afforestation in the MUSL. New hydrological insights for the regionAcross the assessment period of 28 April to 3 October 2016, the total transpiration was determined to be about 294.4 mm. As LAI increased, while the transpiration tended to increase and the evaporation to decrease, the evapotranspiration tended to increase with increase of LAI until LAI =2.0 and then plateaued for LAI >2.0. On the other hand, the recharge rate tended to decrease with increase of LAI until LAI =2.0 and then plateaued for LAI >2.0. Overall, the impacts of Salix psammophila afforestation on soil-water replenishment and groundwater recharge would plateau for LAI >2.0, mandating a good balance between solving large-scope eco-environmental problems by Salix psammophila afforestation and sustaining water resources in the long run.