Bee Communities across Gap, Edge, and Closed-Canopy Microsites in Forest Stands with Group Selection Openings

As insect pollinator populations continue to decline, it is essential to understand the impacts of anthropogenic activities, including forest management, on pollinator communities. Although multiple studies have shown that clearcutting is beneficial for bees, other less intense, selective silvicultural methods that result in disproportionate increases in edge habitat within stands are less well understood. We investigated bee community characteristics across microsites (center of cut, edge of cut, and closed-canopy forest) in three mixed-mesophytic forest stands subjected to group selection cuttings. Results revealed bee communities in the center of cuts and their edges to differ from those in forest microsites, and their diversity measures were higher than in forest microsites. Within-stand edge microsites did not differ from their cut centers in terms of their communities or their diversity. Finally, center of cut and edge microsites combined, and forest microsites, were characterized by different indicator species, thereby exemplifying differences between these two microsite groupings. These results suggest that group selection harvests support differing communities of bees across microsites and sustain a wide range of bee species, and that edges within these forest stands behaved more like extensions of canopy gap openings despite differences in forest physiognomy.