Environmental and floristic differences between three contrasting study areas in an alpine ecosystem: Hardangervidda National Park, Southern Norway

Abstract

Alpine vegetation has been the main focus for many botanists during decades and it has been shown that snow is one of the most important variables explaining vegetation patterns in mountain ecosystems. However, other environmental variables, especially at the local scale, may also have a relevant impact on species abundance and distribution. That is caused by the existence of environmental gradients in alpine ecosystems combined with the existence of microclimates. This study seeks to widen the knowledge on how snow and other environmental variables affect vegetation as well as to infer the impact of the particularities of each study area at the local scale and to model the response of different ecological groups. Thus, the main aims can be summarised as: (1) to interpret the principal environmental gradients reflected by the DCA axes, (2) to interpret the data by the use of Ellenberg indicator values, (3) to model the response of five selected ecological groups by using GLM (4) to test the differences between the three study areas by using Kruskal-Wallis, (5) to group the plots into several plant communities based on their floristic similarities by using TWINSPAN. DCA axis 1 was found to be related to snow cover while DCA axis 2 represented the importance of the local topography and microclimates. Eight different plant communities were sorted by TWINSPAN. Glaimane and Mogen were the most similar sites whereas Stigstuv was slightly more different from them both. It was concluded that local traits at Glaimane and Stigstuv were strong determinants themselves on plant species abundance and distribution.