Lemming Grazing on Snowbed Vegetation during a Population Peak, Northern Norway

Abstract

The impact of a lemming population on a snowbed in northern Fennoscandia was examined during a population peak. Twelve exclosures and 12 open plots were established on a moderately early snowbed. The plots were photographed in autumn 1988, spring 1989, autumn 1989, and autumn 1990, and the cover of graminoids, woody plants, lichens, litter, lemming feces, and mosses were measured. The changes in cover were analyzed with repeated measures ANOVAs. The lemmings significantly decreased cover of graminoids by 33% and mosses by 66% during the peak winter. Our results show that grazing needs to be considered when discussing the development of snowbed vegetation.