The Effect of Woody Encroachment on Evapotranspiration in a Semi-Arid Savanna

Over the past century, increases in indigenous woody plant species, also known as encroachment (WE), has occurred grasslands and savannas across globe. While impact on grassland savanna composition productivity been well studied, little is of impacts hydrological cycle. WE may increase evapotranspiration (ET) losses, leading to reduced infiltration ultimately freshwater availability, which particular concern arid semi-arid areas. The aim this study was determine effect Colophospermum mopane (mopane) ET a located South Africa. Mopane widely distributed southern Africa, one main encroaching species region. Following an assessment validity two surface renewal approaches, SR1 SRDT, against short eddy covariance campaigns for sensible heat flux estimation, approach used estimate at experimental clearing trial from November 2019 July 2022. For drier years study, removal trees had ET. However, wettest year decreased by 12%, supporting hypothesis that conversion grass dominance can Annual exceeded annual rainfall all 3 years, indicating vegetation supplements its water use with soil accumulated during previous wet seasons, or tree roots facilitate hydraulic lift deep water, groundwater, depths within rooting depth both grasses. Further research needed confirm exact mechanism involved, consequences groundwater streamflow landscape scales.