Abstract
Species-rich grasslands are key habitats for bumblebees. Intensive agricultural practices such as frequent mowing and high grazing pressure have led to significant declines in floral resources in grasslands, contributing to pollinator declines. We investigated the effects of delayed mowing and delayed grazing on bumblebee and floral communities in species-rich grasslands in north-west Ireland. Using a paired field design, we monitored bumblebee and floral abundance, species richness, and diversity, over two growing seasons under both delayed and conventional management regimes. Both delayed mowing and delayed grazing significantly increased floral and bumblebee abundance. These effects were more pronounced for common than rare bumblebee species, which may be related to the later emergence of rare species that require resources later in the season when grazing or mowing has been reinstated. In the delayed and conventional mowing fields, some pre-existing differences in floral abundance were present so further work is needed to confirm findings of this treatment. Overall, we demonstrate that adaptive land management strategies—particularly those that reduce summer time disturbance—can enhance bumblebee communities and floral resources, and can be used for bumblebee conservation in agricultural landscapes. Implications for Insect Conservation: Delaying mowing and reducing grazing pressure could measurably enhance floral-resources and support bumblebee abundance. Incorporating such practices into agrienvironment schemes, and supporting farmers with their implementation, can improve habitat quality and promote longterm conservation of bumblebees in grassland landscapes.