Forest restoration treatments indirectly diversify pollination networks via floral- and temperature-mediated effects

In North American conifer forests a variety of federally initiated thinning programs are implemented to restore pre-European settlement forest structures, but these changes may impact ecosystem function via impacts on sensitive biotic communities. Across the wildland-urban interface of the Front Range region of Colorado, agencies associated with the ‘Collaborative Forest Landscape Restoration Program’ (CFLRP) have implemented thinning treatments across thousands of hectares of ponderosa pine forest; here we leverage these treatments as an experimental framework to examine thinning effects on a pollinator community. We measured variation in forest structure and sampled bee community assemblages using multiple methods (trapping and netting) to compare bee biodiversity and patterns of floral visitation by bees (bee-flower networks) between mechanically thinned stands that were 3–10 years post-treatment and non-thinned stands. Three key findings emerged: (1) Native bee abundance, richness, ...