Globally, ecosystems are experiencing state changes in vegetation as a result of human activity (e.g. propagation of invasive species, land use change and management practices (e.g. grazing, fire), and anthropogenic climate change). Parts of South Africa, the Mediterranean and the western United States are experiencing woody encroachment (Knapp et al., 2008; Maestre et al., 2009; Stevens et al., 2016), while the southern Amazon, northern Australia, Hawaii and the Great Basin ecoregion of the United States are experiencing grassification or savannization (Bradley et al., 2006; Hoffmann et al., 2004; Litton et al., 2006; Setterfield et al., 2010). These vegetation state changes may be accompanied by changes in ecosystem function including altered C storage and fluxes, energy balance, hydrology, nutrient cycling and biodiversity (Davidson et al., 2012; Ehrenfeld, 2010; Pearson et al., 2013). For example, non‐native plants have been linked to increased net primary productivity and faster decomposition relative to their native communities (Ehrenfeld, 2003, 2010; Liao et al., 2008). In this study, we synthesize the dozens of individual studies on the effects of Bromus tectorum L. (cheatgrass) invasion in sagebrush systems on C storage to provide valuable information for resource management in the Great Basin, as restoration of native vegetation provides an opportunity for C sequestration and climate change mitigation (Bastin et al., 2019).