The Seasonal Water Balance of Western-Juniper-Dominated and Big-Sagebrush-Dominated Watersheds

The combined impacts of woody plant encroachment and climate variability have the potential to alter water balance in many sagebrush steppe ecosystems Western USA, leading reduced availability these already water-scarce regions. This study compared water-balance characteristics two adjacent semiarid watersheds central Oregon, USA: one dominated by big western juniper. Precipitation, springflow, streamflow, shallow groundwater levels, soil moisture were measured. evapotranspiration was calculated using Hargreaves–Samani method. Potential a approach used calculate seasonal actual evapotranspiration. aquifer recharge Water-Table-Fluctuation-Method. Evapotranspiration, followed deep percolation, accounted for largest portion (83% 86% annual precipitation) output both watersheds. Springflow streamflow rates generally greater at sagebrush-dominated watershed. Snow-dominated years showed amounts percolation than where larger precipitation fell as rain, even when total similar. study’s results highlight role vegetation dynamics, such juniper encroachment, characteristics, on rangeland ecosystems.