Potthoff, K. and Stroth, V., 2011. Patterns of vegetation change on alpine mountain summer farms in Norway. Geografiska Annaler: Series A, Physical Geography, 93, 163–174. DOI: 10.1111/j.1468‐0459.2011.00427.x ABSTRACT This study investigated the impact of long‐term grazing and its abandonment on alpine vegetation. For vegetation changes after the cessation of grazing, previous studies show that the most important
environmental variables are ‘nutrient content of the soil’, ‘current use’ and ‘time since abandonment’. The current study focused on the relative importance of these variables. Vegetation data and environmental variables of three mountain summer farms in
Western Norway with similar ecological site conditions, but different grazing histories and present states of use, were analysed with the help of ordination methods. The results showed that mountain summer farming created a clear difference between areas at a larger distance from the farmsteads
and those in the immediate surrounding of the buildings. The former are characterized by species typically occurring in habitats with low disturbance, the latter by species characteristic for grazed habitats. This confirmed results of previous studies of sub‐alpine and alpine mountain
summer farms. However, considering the current differences in grazing intensity among the farms, vegetation at a greater distance from the farmsteads differed surprisingly little. Changes after abandonment of mountain summer farming occurred slowly, and the results emphasized the importance
of the accumulated soil nutrients in retarding or even preventing vegetation changes.