Relative effects of local and landscape factors on pollinator communities in grasslands and wet meadows along the Sélune river, France

National audience

English. Pollinators provide a crucial ecosystem service by contributing to the reproduction of many wild plant species as well as crop plant species. Pollinators are facing pressures from multiple drivers leading to their declines with potentially serious implications for human food security and health, as well as ecosystem functions. Concern over pollinator declines has sparked a remarkable increase in studies assessing threats to pollinators and quantifying the impact of their decline on pollination services. Landscape changes have been identified as one of the major drivers of pollinator declines. Thus, understanding the effects of landscape composition and configuration on pollinators is crucial for the prevention of further pollinator loss and to help design strategies to protect pollinators in human‐dominated landscapes. Most previous studies examining the response of pollinator richness, abundance and composition to landscape composition showed a negative effect of the proportion of agricultural land. Landscape configuration can also play an important role: decreased patch size and reduced connectivity of landscape elements have been identified as important drivers of species richness declines. However, studies assessing the effects of landscape characteristics over time, even within a year, are less common. Furthermore, the majority of existing literature focuses on specific hymenopteran groups, but there is a lack of information on the effect of landscape on non‐bee taxa and plant-pollinator interactions. Here, we investigated the response of pollinator communities to landscape composition and configuration. To capture intra-annual variability of plant-pollinator interactions, we surveyed both pollinators (honeybees, wild bees, bumblebees, syrphids and butterflies) and flowering plants, every 15 days from May to September 2018. Surveys were carried out in 7 grasslands and 7 wet meadows located along the Sélune river, Manche (France). Fields were selected to represent a gradient in landscape heterogeneity.