Biodiversity and pollination: Flowering plants and flower-visiting insects in agricultural and semi-natural landscapes

The dissertation describes the effects of plant and insect diversity on pollination of wild plant species. As biodiversity is decreasing due to human activities, it is important to know the effects of lower species richness on ecosystem functioning. One such ecosystem function is pollination by insects. The main question of the thesis therefore is: Is a high biodiversity important for the pollination of entomophilous wild plant species in agricultural, fragmented landscapes? Both field surveys (descriptive analyses) and experiments (garden and field) were used. In the field surveys, the diversity of flowering plants and their flower visitors were measured with transects of road verges and ditch banks, situated in landscapes differing in agricultural land use. Furthermore, experiments with potted plants of a number of selected species were performed. The effects of land use on plant and insect diversity were analysed, and subsequently the effects of these diversities on flower visitation, insect behaviour, pollination and seed set.