Session

Extensively managed grasslands are crucial ecosystems for wild bees, providing essential resources such as pollen, nectar, and nesting sites. However, these ecosystems face significant threats from land-use intensification, abandonment, and climate change. In mountain regions, grasslands span from low to high elevations and are therefore characterized by strong changes in abiotic conditions. Due to these variations, the effects of land-use intensity observed in lowland studies cannot be directly extrapolated to higher elevations. In this study, we investigate the potential synergistic and additive effects of land-use intensity along an elevational gradient. We assume that reduced land-use intensity promotes a more diverse wild bee community composition even at higher elevation, where abiotic conditions are a limiting factor. Understanding these effects is critical for developing targeted conservation strategies, particularly for climate change adaptation. We assessed wild bee communities across 30 grasslands characterized by a varying degree of land-use intensity and elevation (700 – 2100 m a.s.l.) using time- and area-standardized transect walks, along with yellow, white, and blue pan traps. Surveys were conducted over two sampling seasons from May to August. During the first season, we recorded a total of 1,216 wild bees representing over 130 species. Preliminary analyses indicate that the effect of increasing elevation on wild bee abundance is more pronounced when flower richness decreases. Wild bee species richness also decreases with declining flower richness, suggesting a positive effect of extensive grassland management practices on wild bees along elevational gradients. Additional analyses focusing on functional diversity, community composition and plant-bee interactions will offer a more comprehensive understanding of how wild bee communities respond and adapt to varying land-use intensities and changing climatic conditions.