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.Keywords: extensive grazing, rangeland, soil erosion, sustainable management, tundra
YFIRLIT
Áhrif sauðfjárbeitar á íslensk vistkerfiSjálfbaerni sauðfjárbeitar á Íslandi hefur oft verið dregin í efa enda tengja margir beit við mikla jarðvegseyðingu og hnignun vistkerfa. Hér tökum við saman þaer rannsóknir sem birtar hafa verið um áhrif sauðfjárbeitar á vistkerfi íslenskra úthaga. Alls fundust 16 rannsóknir, birtar í 44 skjölum, flest á skýrsluformi. Fyrir flestar vistfraeðibreytur voru rannsóknirnar of fáar til að draga maetti almennar ályktanir útfrá þeim. Safngreining (e. meta analysis) sýndi þó að beit hefur áhrif á uppbyggingu plöntusamfélaga og eykur rof í gróðurþekjunni. Úthaginn verður þar af leiðandi viðkvaemari fyrir jarðvegsrofi. Ljóst er að afla þarf betri þekkingar á áhrifum beitar á vistkerfi íslenskra úthaga svo tryggja megi sjálfbaera sauðfjárbeit sem haefa aðstaeðum á hverju svaeði fyrir sig.