Conservation grasslands support diverse native bee assemblages in agroecosystems

The U.S. Department of Energy projects that millions of acres of croplands will be converted to new bioenergy crops in coming years. Such shifts in crop production are expected to alter the agricultural landscape, potentially affecting organisms inhabiting these agroecosystems. In particular, there is growing concern about how bees will respond to changes in land-use. Our research examines how landscape attributes, such as vegetation cover, floral diversity, and land-use influence bee abundance and diversity. The goal of this project is to better understand how future land-use change may affect bees in agroecosystems located in the Colorado high plains region. In 2013, we sampled bees and characterized landscape attributes in grassland habitats at 32 field sites located in northeastern Colorado. In addition to rangelands, field sites included Conservation Reserve Program (CRP) grasslands, allowing us the opportunity to evaluate CRP plantings as habitat for wild and managed bees. These grassland habitats, in particular, had a diverse and abundant native bee community. Preliminary results indicate that CRP fields supported approximately 30% more bees than rangeland habitats. Long-horned bees (tribe Eucerini) were especially common along the edges of conservation plantings, likely due to the availability of sunflowers, which were dominant floral resources for these bees. We are currently exploring how landscape attributes drive community composition within vegetation types and how these habitats may be influenced by future changes in land-use.