A novel application of the Price equation reveals that landscape diversity promotes the response of bees to regionally rare plant species

Abstract

Bees are ecosystem service providers that are globally threatened by losses of plant diversity. However, effects of multi-species floral displays on bees in agro-ecosystems with variable landscape context remain poorly understood, hindering pollinator conservation tactics. We addressed this knowledge gap through a novel application of the modified Price equation to evaluate responses of bees to diverse floral communities on 36 farms in Washington, USA, over 3 years. We found that floral richness, not floral identity, was the best predictor of floral visits by bees. However, the benefits of regionally rare floral species (i.e. plants found at relatively few sites) were only fully realised when farms were embedded in diverse landscapes. Our analysis used the modified Price equation to demonstrate that plant diversity, rather than specific plant species, promotes pollinator visitation, and that diverse landscapes promote the response of pollinators to regionally rare plant species.

Keywords: Bees; Price equation; complementarity; composition; landscape diversity; regionally rare species.