A comparison of influences of cattle, goat, sheep and reindeer on vegetation changes in mountain cultural landscapes in Norway

Abstract

Earlier land use in European mountains included grazing by different kinds of livestock, while today it may be more homogenous, and the grazing may have either been intensified or been abandoned. Different domestic animal species graze in different areas of the landscape. Therefore, grazing stocks composed of different species have an unequal effect on the landscape. This study compares the influence of four domestic animal species (cattle, sheep, goats, reindeer) on landscape dynamics in Jotunheimen, a Norwegian mountain range. Interviews and maps showing grazing land of domestic animals were performed to collect information about land use in the summer farm surroundings. Grazing pressure maps (prior to 1960 and 1960–2002) using the land use information obtained, and vegetation maps (from the 1960s and 2002) using aerial photographs, were digitized. Vegetation was spatially linked with grazing pressure using GIS and multiple multinomial and linear regressions were used to investigate each species’ effect on vegetation type change and displacement of the forest line, respectively. The results show that cattle grazing influenced transitions from grasslands, cattle together with goats affected transitions from heaths, and cattle, goats, and reindeer influenced displacement of the birch forest line. High grazing pressure from these three domestic animals suppressed forest and scrub establishment in open habitats. Only goats, however, caused transitions from scrub and birch forest to open vegetation types.