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Research article - Peer-reviewed, 2021

Landscape complexity benefits bumble bee visitation in faba bean (Vicia faba minor L.) but crop productivity is not pollinator-dependent

Lundin, Ola; Raderschall, Chloe A.

Abstract

Faba bean (Vicia faba minor L.) is partially dependent on insects for pollination, but the degree of pollinatordependency and whether crop productivity is limited by insufficient insect pollination remain unknown. We monitored insect pollinators and their foraging behaviors (i. e., legitimate flower visitation, nectar robbing and extra-floral nectary visitation) in a total of 20 faba bean fields of a single cultivar (Tiffany) 2018?2019. Focal fields were situated along a gradient of landscape complexity. In each field, a pollination experiment was established, where plants were either bagged to exclude pollination by insects or remained open for pollinator visits. In addition, all flowers on half of the bagged and open-pollinated plants were pollinated by hand to measure the degree of pollen limitation. We found that bumble bee abundance was higher, and legitimate flower visitor abundance tended to be higher, in complex landscapes with more semi-natural habitat, indicating that the faba bean pollination potential is higher in complex landscapes. The pollination experiment showed that the number of beans per pod was lower in bagged plants compared with other treatments in one of the years, but the lower number of beans per pod was compensated for by a higher individual bean weight, such that there was no pollinator-dependency or effect of hand pollination on total bean mass per plant. We conclude that to be able to characterize the value of insect pollination services in faba bean we need an improved understanding of how pollinator-dependency varies across modern cultivars, and how environmental conditions can increase or, as in our case, cancel this pollinator-dependency.

Keywords

Apis mellifera; Bombus; Hand pollination; Landscape complexity; Pollen limitation

Published in

Agriculture, Ecosystems and Environment
2021, volume: 314, article number: 107417
Publisher: ELSEVIER

Authors' information

Swedish University of Agricultural Sciences, Department of Ecology
Swedish University of Agricultural Sciences, Department of Ecology

UKÄ Subject classification

Agricultural Science

Publication Identifiers

DOI: https://doi.org/10.1016/j.agee.2021.107417

URI (permanent link to this page)

https://res.slu.se/id/publ/112083