Landscape composition modifies pollinator densities, foraging behavior and yield formation in faba beans

• Published in: Basic and applied ecology Vol. 61; pp. 30 - 40
• Main Authors: Beyer, Nicole, Gabriel, Doreen, Westphal, Catrin
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.06.2022; Elsevier
• Subjects: Broad bean weevil; Ecosystem services; Grain legumes; Mass-flowering crops; Resource allocation; Broad bean weevil; Mass-flowering crops; Ecosystem services; Grain legumes; Resource allocation
• ISSN: 1439-1791
• DOI: 10.1016/j.baae.2022.03.002

•Landscape composition modulates foraging behavior of faba bean pollinators.•Landscape composition affects bee pollinator densities in bean fields.•High semi-natural habitat land covers increase bee densities in bean fields.•Insect pollination increases number of beans per pod in faba beans.•Bee density effects on yield components depend on landscape composition. Wildlife-friendly management practices promote pollinators and pollination services in agricultural landscapes. Wild bee densities are driven by landscape composition, as they benefit from an increased availability of nesting and foraging resources at landscape scale. However, effects of landscape composition on bee foraging decisions and consequences for crop pollination have rarely been studied. We investigated, how landscape composition affects bee densities and foraging behavior in faba bean (Vicia faba L.) fields and how this impacts faba bean yield. We recorded densities and nectar robbing behavior of honeybees, long- tongued and short-tongued bumblebees in faba bean fields in eleven landscapes with varying landscape composition (e.g. land cover of oilseed rape, faba bean and semi-natural habitats). Moreover, we assessed yield components of faba beans via pollinator exclusion experiments. Increasing covers of faba bean and semi-natural habitats positively influenced bumblebee densities, while high oilseed rape covers negatively affected short-tongued bumblebee densities in bean fields. Increased faba bean covers enhanced the proportion of nectar-robbing short-tongued bumblebees. The number of beans per pod was increased by insect pollination, while the number of pods was decreased; these effects however depended on variety. Landscape composition interacted with bee densities in shaping yield components in V. faba. Our study emphasizes the importance of considering landscape management to maximize crop yields, as shown for the case of faba beans. The composition of agricultural landscape can modulate bee densities in crop fields, bees foraging behavior and pollination services.