Alpine vegetation along multiple environmental gradients and possible consequences of climate change

Alpine plant communities are being subject to climate change, resulting in the need for plants to adapt to new conditions. In this study, we investigated changes in vascular plant diversity along a coast-inland gradient in central Norway. At four different mountains, species were registered in 100 m(2) plots, laid out from the forest line to the summit. In addition, plots were grouped into snow cover duration (short, medium, and long) and aspect (North, South, East, and West). We documented richness and spatial turnover of species and functional groups (trees and tall shrubs, dwarf shrubs, herbs, graminoids, and seedless plants) along the different gradients using glm and RDA. Thereafter, we included variables from climate scenario models in the derived glm's to estimate how species richness and the distribution of these groups could be impacted by future climate change. Our results show that there are significant changes in species and functional groups along the regional gradient. Further, also local variation due to altitude and snow cover duration influenced species distribution and composition. Predictions of future vegetation showed an increase in species richness compared to present, with most changes occurring in areas of long and medium snow cover duration. We predicted the main changes to occur at lower altitudes. Here, dwarf shrubs and graminoids were expected to increase the most in number of species, whereas species of trees and tall shrubs were expected to increase the most in proportion.