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Brush management activities have traditionally been undertaken to reduce woody cover in an effort to improve forage production on managed rangelands where undesirable woody plants have proliferated. Yet, economic analyses suggest that this sole focus is often financially unjustified. Quantification of the long-term effects on other ecosystem services (ESs) (biodiversity, carbon sequestration, water quality, soil nutrients) and associated trade-offs will enhance our ability to objectively evaluate the ecological impacts of woody encroachment and the cost-benefit of brush management as a conservation practice. Long-term, watershed-scale assessments of ESs, however, are lacking. In an effort to better position us to make these assessments, we are quantifying the effects of brush management on a suite of ESs on four instrumented watersheds on a velvet mesquite (Prosopis velutina)-invaded desert grassland in southeastern Arizona. Pre-treatment herbaceous diversity and aboveground (herbaceous and woody live and litter) and belowground (soil organic C and roots to 20 cm) carbon pools were quantified in 2015 and early 2016 on all watersheds prior to initiating an aerial herbicide brush management treatment in June 2016 on two of the watersheds. These variables were subsequently re-quantified in September 2016. Early results indicate that the frequency of occurrence of both native and nonnative grasses has increased on the treated watersheds relative to controls. In addition, there was a 100% increase in herbaceous biomass. Data will be collected for at least three additional years and will be supplemented with unmanned aerial vehicle imagery. Extended monitoring will be conducted under the auspices of the USDA-ARS Long Term Agricultural Research program. Collectively, these data will be used to parameterize ecosystem and hydrological simulation models to predict long-term ecosystem responses and provide for more effective and comprehensive cost-benefit analyses of brush management.