Pollinator diversity, floral resources and semi-natural habitat, instead of honey bees and intensive agriculture, enhance pollination service to sweet cherry

Abstract

Declines of pollinator diversity are causing concern about pollination service security for agriculture and natural ecosystems. Landscape composition has been found to regulate the diversity of pollinator communities and their corresponding pollination services in agricultural fields, with previous research concluding positive effects of semi-natural habitat or negative effects of intensive agriculture. In our study we assessed pollinator diversity and pollination services in sweet cherry orchards (Prunus avium) along two non-collinear, independent gradients of semi-natural habitat and intensive agriculture (i.e. percentage of cultivated land) around the orchards. The influence of floral resources in the herb layer in the orchards was also assessed. Our results show that semi-natural habitat clearly support pollinator species richness and wild pollinator abundance. Next to semi-natural habitat, flowering plants in the herb layer of the orchards was an additional driver of pollinator diversity in sweet cherry orchards. Although approximately 80% of all flower visitors were managed honey bees, fruit set of sweet cherry was only clearly linked to pollinator species richness and wild pollinator abundance. Management strategies to support sweet cherry production might include the creation of semi-natural habitat around orchards and the promotion of floral resources in the orchard’s herb layer to support pollinating insects.