Impacts of field-edge flower plantings on pollinator conservation and ecosystem service delivery – A meta-analysis

Abstract Planting flowers along crop field edges is an increasingly common management strategy for addressing pollinator declines and improving crop pollination. However, few reviews have been published summarizing the efficacy of this specific management practice and how it impacts ecosystem service delivery to crops. We conducted a systematic review (54 studies) and meta-analysis (4–29 studies, depending on the response) to determine whether such plantings 1) increase pollinator abundance or richness within field edges, 2) increase the abundance or richness of pollinators visiting crop flowers, or 3) improve crop yields. Our review and meta-analysis suggest that field-edge flower plantings are highly effective at increasing pollinator richness and abundance in field edges and that plantings become more effective as they mature. However, the influence of field-edge plantings on crop pollination and yield is inconsistent. Planting size and richness did not change these results. While this analysis shows that field-edge flower plantings consistently increase pollinator abundance and richness, there remain critical gaps in our knowledge of when and how plantings can improve ecosystem service provision and delivery. Determining if field-edge plantings affect pollinator population growth may clarify how plantings improve crop pollination, while further research on landscape context and crop type may define when this happens.