Human Population Growth and Accessibility from Cities Shape Rangeland Condition in the American West

Drylands cover 40 % of the global land surface and more than 3 billion people worldwide are dependent on the ecosystem services (ES) that they provide (Hoover et al., 2020). Dryland ecosystems are subject to multiple forces of change, including climate change, invasive plants, and increasing wildfires (Maestre et al., 2016). For example, human pressure and land use intensification can quickly induce changes in healthy drylands that lead to degradation, thus reducing their capacity to recover from extreme climate events (Gunderson, 2000, Sun et al., 2021). We define degradation as a transition from a functional native ecosystem to an undesired state that may include lower biodiversity and provide fewer ecosystem services (Maestre et al., 2016). For many drylands ecosystems, reversing degradation is challenging, due to hysteresis (Scheffer et al., 2001, Suding et al., 2004). Potential cascading feedbacks between multiple drivers of change emphasize an urgent need for research on socio-ecological dynamics in drylands to inform sustainable land management (Nkonya, Winslow, Reed, Mortimore, & Mirzabaev, 2011).