Connectivity and edge effects increase bee colonization in an experimentally fragmented landscape

Though landscape corridors increase dispersal of many animals and plants, it remains unknown whether these positive effects extend to the process of colonization and establishment of new populations in fragments. Working in experimentally fragmented landscapes, we tested how two aspects of habitat fragments altered by corridors - connectivity and edge-to-area ratio - determine patterns of colonization by a solitary, cavity-nesting bee Megachile rotundata. We found that though connectivity initially affected rates of nest-site occupation, edge-to-area ratio ultimately determined the final patterns of patch occupation and nest building, likely due to habitat selection by our focal species. Bee colonization was also higher in patches with higher abundances of their preferred food resources, flowers from the Fabaceae family. Our results show the importance of considering the effects of both connectivity and edge on population dynamics in habitat-based conservation.

Automated summary

The study focused on how landscape corridors affect the colonization and establishment of new populations in fragmented habitats by investigating the habitat preferences of solitary, cavity-nesting bees. It was found that connectivity initially influenced nest-site occupation rates, while ultimately, edge-to-area ratio determined patch occupation patterns, emphasizing the importance of both factors in population dynamics for habitat-based conservation efforts. Additionally, higher colonization rates were observed in patches with abundant flowers from the Fabaceae family, indicating the significance of food resources in bee populations.