Inter-Relationships between Treeline Position, Species Diversity, Land Use and Climate Change in the Central Scandes Mountains of Norway

Abstract

Vegetation samples collected along altitudinal transects through the treeline ecotone in the central Scandes Mountains, Norway, were used to analyse the relationships between species diversity, species turnover and the performance of the tree layer. The study area has a long history of extensive grazing by domestic animals. The floristic composition showed a continuous change along the boreal-alpine gradient. The number of species was more or less constant throughout 600 altitudinal m centred around the treeline, and the floristic similarity between neighbouring altitudes did not show any abrupt changes at any particular altitude. The treeline position (Betula pubescens Ehrh.) spanned 190 altitudinal m (range 980-1170 m a.s.l.). The number of trees and the basal area each decreased continuously with increasing altitude from 300 altitudinal m below the treeline. The