Combined effects of impatiens glandulifera invasion and landscape structure on native plant pollination

1. Habitat loss, land use intensification and biological invasions are all threatening pollinator com-munities, but the combined effects of these factors on pollinator diversity and pollination services have not been studied yet. 2. Here, we tested the hypotheses that (i) the invasive plant Impatiens glandulifera outcompetes native plant communities for pollinators, and (ii) pollinator abundances depend on landscape struc-ture, but are modulated by this mass-flowering invader. 3. We selected 14 study sites in riparian habitats along a landscape gradient with decreasing pro-portion of natural land cover. Within each site paired invaded or non-invaded plots were studied. We performed standardized surveys of pollinators and established experimental plots by adding the native plant Raphanus sativus to assess the impact of I. glandulifera on visitation rates and seed set. 4. Impatiens glandulifera was well integrated in the plant–pollinator network, being visited by several native pollinators, mainly bumblebees. The invader received higher visitation rates than simultaneously flowering native riparian plants and the experimentally added native R. sativus. However, visitation rates to the native plant community showed no significant differences betwee