Habitat fragmentation: a threat to arctic biodiversity and wilderness
Fragmentation is often defined as a decrease in some or all types of natural habitats in a landscape, and the dividing of the landscape into smaller and more isolated pieces. As the fragmentation process develops, the ecological effects will change. Fragmentation can be caused by natural processes such as fires, floods, and volcanic activity, but is more commonly caused by human impacts. It often starts with what are seen as small and harmless impacts. As human activity increases, however, the influence of fragmentation becomes greater. In the end, it leads to devastating effects on native species, a total change to the landscape, and the destruction of the area’s wilderness heritage.
Today, in the vast circumpolar area, many ecosystems are still relatively undisturbed. They are large enough to allow ecological processes and wildlife populations to fluctuate naturally, and for biodiversity to evolve and adapt. These areas, which are among the last remaining wilderness areas of the world, therefore, constitute a global heritage.
However, Arctic ecosystems are under increased pressure from development activities. Road construction, pipelines, mining activities, and logging are among the significant causes of fragmentation. In the long run, the cumulative effects of such activities will cause a large loss of biodiversity and will reduce the Arctic’s wilderness heritage considerably. For example, roads block the movement of small animals, expose large animals to heavy hunting pressure and poaching, cause sedimentation of rivers from erosion, and stimulate more development, thus creating further habitat fragmentation. Cumulative impacts may be more serious in the Arctic as the permafrost, underlying the thin biologically active layer, magnifies disturbances and makes restoration efforts difficult or impossible.
Norway as an example
In mainland Norway, much habitat has been lost through piecemeal development, particularly during the past 20 to 30 years. During the last century undisturbed or pristine wilderness areas (more than 5 km from roads and other infrastructures) have been reduced from 48% of the countryside nationwide in 1900 to 11.8% in 1998. In northern Norway only 24% of land was classified as wilderness in 1998. This trend is largely the result of agriculture, forestry, and hydroelectric development. In the Svalbard archipelago, the wilderness areas are still intact, but proposals for roads to connect coal mines are shadows on the horizon.
Decrease of wilderness areas in Norway. Wilderness is defined as an area lying more than five kilometers from roads, railways, and regulated water-cources (source: Norwegian Mapping Authority).
It is now increasingly realized that large pristine areas, in addition to being crucial to the conservation of biodiversity, are important to national identity and provide opportunities for outdoor recreation, ecological research, monitoring, and education. For the Saami, such areas are important for traditional reindeer herding. Recent political decisions in Norway reflect this changed attitude and place increased emphasis on preservation of wilderness areas. It is important for Arctic nations, which still are blessed with much undisturbed land, to control piecemeal development activities before it is too late.
Jan-Petter Huberth Hansen, Directorate for Nature Management, Trondheim, Norway. From the CAFF publication, Arctic Flora and Fauna, www.caff.is