Abstract
This project will investigate effects of fragmentation and invasion on pollination service to forbs in marginal grassland habitats by combining large-scale field experiments, focal observations of pollinator behavior and monitoring of pollinator abundance. Pollination service will be estimated in large continuous semi-natural grasslands and in road-verges at different distance from these. Furthermore, the effect of the invasive Lupinus polyphyllus, which is common in road-verges, will be studied by comparing pollination success in experimentally invaded and non-invaded sites. Decay in pollination service will be indicated by increased pollen limitation and decreased visitation rates with increased fragmentation or invasion status. The effects of pollen limitation on maternal and offspring success will be investigated, and the importance of pollen limitation for population and metapopulation dynamics will be indirectly studied by seed addition experiments. The novelty and importance of the project lies in (i) a first assessment of the quality of road-verges as an alternative habitat for semi-natural grassland plants, (ii) the incorporation of spatial scale and hierarchical competition/facilitation effects in studies of invasive plants and pollination, and (iii) an evaluation of the ecological importance of pollen limitation and the effect of seed production on population and metapopulation dynamics of the studied species.
Sweden