Dryness, wetness and temporary flooding reduce floral resources of plant communities with adverse consequences for pollinator attraction

1. Climate change alters precipitation regimes worldwide and is regarded as a major threat for pollinators and pollination services. Yet, not much is known on how wetter as well as drier conditions affect food resources for pollinators and pollinator attraction in a multi-species community context. It is unclear how community shifts under changed hydrological conditions might affect pollinators.
2. This mesocosm study addresses existing research gaps by investigating effects of drought, wetness and temporary flooding on floral resources and pollinator attraction within a plant community, initially including nine insect- and six wind-pollinated species. Floral resources were assessed over three growing seasons monitoring community descriptors (percentage of herbs and herbaceous species richness, presence of flowering insect-pollinated individuals), floral traits (flower height, size and weight, floral sugar content of one key species) and proxies for plant fitness (pollinator attraction,...