Forest proximity supports bumblebee species richness and abundance in hemi-boreal agricultural landscape

Abstract

To create effective conservation measures for pollinators, we need to understand how landscape structure affects their distribution. We examined the effects of forest proximity on bumblebee communities in a modern agricultural landscape in the forest-rich hemi-boreal region. We contrasted bumblebee communities in field margins located next to forest with margins located next to open habitats. We also assessed the effect of forest proportion in the surrounding landscape on bumblebee species richness and abundance. Additionally, the effects of margin area, and flower abundance, on the species richness and abundance of bumblebees were evaluated. Both the species richness and abundance were higher in the margins next to forest compared to the margins next to open habitats. Higher proportion of forest in the surrounding landscape, as well as larger margin area and higher flower abundance, also resulted in the higher species richness and abundance of bumblebees. Importantly, these positive responses to increasing forest cover and habitat quality occurred only, or were considerably stronger, in the margins next to forest. In conclusion, our results show that the proximity of forest favours the species richness and abundance of bumblebees in modern agricultural hemi-boreal landscapes. The proportion of forest cover in the region should be considered while developing landscape-level conservation strategies, and margins next to forest should be given priority while planning local conservation measures.