Shifts in honeybee foraging reveal historical changes in floral resources

Abstract

Decreasing floral resources as a result of habitat loss is one of the key factors in the decline of pollinating insects worldwide. Understanding which plants pollinators use is vital to inform the provision of appropriate floral resources to help prevent pollinator loss. Using a globally important pollinator, the honeybee, we show how changes in agricultural intensification, crop use and the spread of invasive species, have altered the nectar and pollen sources available in the UK. Using DNA metabarcoding, we analysed 441 honey samples from 2017 and compared these to a nationwide survey of honey samples from 1952. We reveal that shifts in major plants foraged by honeybees are driven by changes in the availability of these plants within the landscape. Improved grasslands are the most widespread habitat type in the UK, and management changes within this habitat have the greatest potential to increase floral resource availability.

Laura Jones et al. compare honey samples across the UK from 2017 to a nationwide survey of honey samples from 1952 in order to determine how nectar and pollen sources have changed over time. They find that shifts in major plants foraged by honeybees are driven by changes in the availability of these plants within the landscape, and focus on improved grasslands as the most widespread habitat type and a potential target for management efforts to increase floral resource availability.