POLLINATION IN ALPINE NORWAY - FLOWERING PHENOLOGY, INSECT VISITORS, AND VISITATION RATES IN 2 PLANT-COMMUNITIES

Pollination studies in European alpine communities are few. The object ive of this study was to describe the pollination ecology in two alpin e plant communities at Finse, southwestern Norway. Because of late sno wmelt and early winter at Finse, the time available for flowering and seed maturation is restricted. Flowering was concentrated at the begin ning of the season in both communities, and large overlaps in flowerin g time were found for most species. In one of the communities, floweri ng peaks were significantly clumped, whereas in the other they were ra ndomly distributed through the season. However, in this community, fiv e insect-pollinated species flowered simultaneously early in the seaso n. Diptera almost exclusively dominated the visitor assemblage. Most p lant species pairs had high overlaps in flower visitor species. Specie s flowering simultaneously attracted the same visitor species. In one community, eight species pairs flowered sequentially and shared visito rs. Visitation rates were highest at the lowest elevated site. The res ults are compared with those obtained in other alpine areas. It is arg ued that selection for an early flowering is probably stronger than se lection pressures resulting from interspecific interactions.