Changes in alpine snowbed‐wetland vegetation over three decades in northern Norway

We have quantified floristic changes in alpine snowbeds and wetland vegetation during three decades and analyzed to what extent these changes are related to initial variations in snow cover duration and distance to groundwater level. Vascular plant species richness and total plant cover were estimated along three transects in northern Norway. Three different vegetation zones were identified along the original transects: relatively dry snowbeds, wet snowbeds and wetlands. The resampling shows major changes in species richness and plant cover. In general, there was a net immigration of species and 13 new species were found. Five rare species with initial low cover were lost. In the dry and wet snowbeds, species richness and total plant cover increased, mostly because of invasion by shrubs, graminoids and herbs. A general trend was that species indicating high soil moisture were strongly reduced. In the wetland zones there were no significant floristic changes but hygrophilous species had decreased and were replaced by graminoids and shrub species with lower water requirements. These floristic changes were significantly related to snow and soil moisture conditions, important factors for rate and direction of change. Contrasting vegetation responses within very short distances demonstrate the importance of detailed knowledge of the actual microhabitats when effects of climate change in alpine habitats are considered.