Evaluating the response of native sagebrush bee communities to invasive grasses

Invasive annual grasses are reshaping sagebrush ecosystems across the west and negatively impacting ecological functions that support native biodiversity. In turn, this has raised concerns about the dynamics of species-rich communities and their presence in invasion-prone landscapes, particular those that serve as keystone groups. To date, very little research has been conducted to assess the status and response of insect pollinator communities in invaded sagebrush systems, despite their importance for supporting plant and wildlife communities. In this study, we evaluated changes in native bee communities as a function of increasing levels of annual invasive grass cover across 35 sites in the Steens Mountain area of southeastern Oregon during summers 2024-2025. This sampling design allowed us to evaluate the changes in community composition across a gradient of invasion by four species of non-native grasses. Although specimen identification is in process, preliminary analysis indicates a diversity of bees across the grass invasion gradient. Taken together, our findings will further understanding of how native bees respond to sagebrush degraded by invasive grasses, and help guide conservation of this endangered ecosystems across western North America.