Abstract
Woody plant encroachment has profound impacts on the sustainable management of water resources in water-limited ecosystems. However, our understanding of the effects of this global phenomenon on groundwater recharge at local and regional scales is limited. Here, we reviewed studies related to (i) recharge estimation methods; (ii) mechanisms by which woody plants impact groundwater recharge; (iii) impacts of woody plant on recharge across different soil and geology; (iv) hydrological repercussions of woody plant removal; and (v) research gaps and needs for groundwater studies. We identified six different methods: water balance, water table, isotopes, chloride mass balance, electrical geophysical imaging, and modeling were used to study the impact of woody encroachment on groundwater. Woody plant encroachment could alter soil infiltration rates, soil water storage, transpiration, interception, and subsurface pathways to affect groundwater recharge. The impact is highly variable, with the extent and the magnitude varying across the soil, substrate, plant cover, and topographic locations. Our review revealed mixed effects of woody plant removal on groundwater recharge. Studies of litter interception, root water uptake, soil moisture dynamics, and deep percolation along with the progression of woody plant encroachment are still limited, warranting further experimental studies focusing on groundwater recharge. Overall, information about woody plant encroachment impacts on groundwater resources across a range of scales is essential for long-range planning of water resources.
Highlights
Woody plant encroachment refers to an increase in density, cover, and biomass of shrubs and trees into areas where they were not present previously [1,2]
This paper provides a holistic review of published research on how woody plant encroachment has impacted deep drainage and groundwater recharge in different parts of the globe
This review provides an overview of available tools and methods that have been used to estimate deep drainage and groundwater recharge potential associated with woody plant encroachment
Summary
Woody plant encroachment refers to an increase in density, cover, and biomass of shrubs and trees into areas where they were not present previously [1,2]. Successful establishment and proliferation of woody species in grasslands and savannas have been attributed to fire suppression, overgrazing, land fragmentation, change in atmospheric chemistry, and various combinations and interactions of those factors [24,25,26] While factors such as fire, grazing, and differential soil properties affect the locality and rate of woody plant encroachment, the upper limit of this physiognomic transformation is controlled by mean annual precipitation [27]. This review provides an overview of available tools and methods that have been used to estimate deep drainage and groundwater recharge potential associated with woody plant encroachment To this end, we conducted a literature database search in web of science
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
