Ecosystem Disturbance in Iceland

Abstract

Iceland is an example of a fragile northern ecosystem where livestock grazing in conjunction with highly erodible volcanic soils and a harsh climate have combined to cause extensive vegetational degradation and soil erosion since settlement in A.D. 874. At the time of settlement about 65? o of Iceland is thought to have been vegetated. Birch (Betula pubescens) woodlands at lower elevations are thought to have covered at least 25% of the country. Willows (Salix spp.) and other dwarf shrubs were dominant above 300 to 400 m elevation. This vegetation evolved in the absence of herbivores and was vulnerable to grazing by livestock introduced at the time of settlement. At present less than 25%o of Iceland is vegetated. Remnants of former birch woodlands occupy only I o of the land area. The value of remaining vegetation for grazing, outdoor recreation, and other purposes has been greatly reduced. Extensive, accelerated soil erosion and continued degradation of vegetation by livestock constitute the most serious environmental problems in Iceland today.