Assessing the Ecological Impacts of Extensive Sheep Grazing in Iceland

The sustainability of sheep grazing in Iceland has been repeatedly questioned as in some areas high stocking rates have been associated with extensive soil erosion and ecosystem degradation. We synthesized all available information on the effects of sheep grazing on vegetation, soil properties and other organisms in the rangelands of Iceland, with special focus on the grey literature. We compiled 347 documents, but only 44 contained extractable data, reporting on 16 studies. The scarcity of studies prevented us from drawing general conclusions for most ecological variables across environmental conditions, but some consistent trends were found. The extent of bare ground was significantly higher in grazed areas and grazing affected plant community structure. The potential for increased soil erosion in grazed areas remains a problem in Icelandic rangelands. A better understanding of the ecological impacts of sheep grazing is required to inform sustainable grazing practices adapted to the local conditions of this region.