Variations in mountain vegetation use by reindeer (Rangifer tarandus) affects dry heath but not grass heath

Question: Are differences in landscape use of semi-domesticated reindeer reflected in the vegetation of summer grazing grounds?Location: Alpine heaths, central east Sweden.Methods: Dry heath and grass heath vegetation plots with inferred grazing intensities (high, intermediate and low) were selected a priori from an interpolated pellet count map compiled in 2002. In each plot, faecal pellets were counted, environmental variables measured and vegetation sampled by listing presence and absence. Species composition was compared with a detrended correspondence analysis, and a canonical correspondence analysis was used to infer relations between species composition and environmental variables. Plots were also clustered to provide groupings for an indicator species analysis.Results: Significant differences in faecal pellet count were present between the highest and lowest grazing intensities for both vegetation types, showing that the pattern in the interpolated pellet maps was robust. Differences in species composition between grazing intensities were found for the dry heath only. Here, there was an apparent grazing gradient, with lichens and mosses in the low-use plots and grasses and herbs in the high-use plots. No such gradient was found for the grass heath.Conclusions: Within the dry heath vegetation type, grazing levels had a subtle effect on the vegetation, while no effects were seen in the grass heath, probably as a result of the dominance of more grazing-tolerant graminoids. Even in the dry heath, species richness did not differ between grazing levels, but the relative abundances of species differed.