- Human impacts on the biodiversity of the Arctic
Biodiversity in the Arctic is affected by pervasive, small-scale, and long-lasting physical disturbance and habitat fragmentation as a side-effect of industrial and urban developments and recreation. Such disturbances, often caused by buildings, vehicles, or pedestrians, can alter vegetation, fauna, and soil conditions in localized areas. A combination of these “patches” can result in a landscape-level mosaic, in effect a series of “new” ecosystems with distinctive, long-term, biodiversity characteristics. These are becoming more widespread in the Arctic and in some cases can, through enhanced productivity and vegetation quality, act as “polar oases” having a wide influence on local food webs.
Forbes et al. reviewed patch dynamics generated by anthropogenic disturbance, based on re-examination of more than 3000 plots at 19 sites in the high and low arctic regions of Alaska, Canada, Greenland, and Russia. These plots were established from 1928 onward and resurveyed at varying intervals, often with detailed soil as well as vegetation observations. Although these patches have mostly experienced low-intensity and small-scale disturbances, “none but the smallest and wettest patches on level ground recovered unassisted to something approaching their original state in the medium term (20–75 years)”. Forbes et al. concluded that “in terms of conservation, anthropogenic patch dynamics appear as a force to be reckoned with when plans are made for even highly circumscribed and ostensibly mitigative land use in the more productive landscapes of the increasingly accessible Arctic”.
Development in the marine environment of the Arctic is currently very limited. However, a recent report on the status of wildlife habitats in the Canadian Arctic stated that “the Arctic landscapes and seascapes are subject to…oil and gas and mining developments [which] continue to expand”. Muir’s analysis of coastal and offshore development concluded that pressures on the marine environment are bound to increase. There will be further exploration for oil and gas. If substantial finds are made under the arctic seas then development is likely to take place. While most known oil reserves are currently on land, offshore exploration, such as that west of the Fylla Banks 150 km northwest of Nuuk in Greenland, will continue to have local impacts on the seabed. Muir also predicted that marine navigation and transport are likely to increase in response to both economic development and as the ice-free season extends as a result of climate change, with the consequent infrastructure developments.
Recreational use of arctic land by people, largely from outside the Arctic, is increasing. Although hikers and their associated trails potentially present few problems, this is not the case for the infrastructure associated with development and for off-road vehicles. Potential problems with trails are associated with vegetation loss along and beside the trail. This leads to erosion of the skeletal soils by wind, frost, or water. There is current discussion about the use of trekking poles and whether, by making small holes in the ground that can fill with water, followed by freeze–thaw cycles, they increase the potential for erosion.
Use of off-road vehicles has increased with their greater accessibility. They can also exert greater environmental pressures than trampling by people. As a result various laws and regulations have been introduced to reduce or eliminate the damage that they cause. In Russia, off-road vehicles are frequently heavy, such as caterpillar tractors. Although it is forbidden to use these in treeless areas in summer, violations are thought to be common. Norway has prohibited off-road driving throughout the year, although different rules apply to snowmobiles. Use of the latter is becoming more frequent, with 10–11 per thousand of the population owning them in Iceland and Norway by the late 1990s; this increases to 17 in Finland, 22 in Sweden, and 366 in Svalbard. The Fennoscandian countries have established special snowmobile routes to concentrate this traffic and so prevent more widespread damage and disturbance to snow-covered habitats.
Implications of infrastructure development and habitat fragmentation, especially the construction of linear features such as roads and pipelines, are less clearly understood. However, Nellemann et al.’s research gave some indications about effects on reindeer. Reindeer generally retreat to more than 4 km from new roads, power lines, dams, and cabins. The population density dropped to 36% of its pre-development density in summer and 8% in winter. In areas further than 4 km from developments, population density increased by more than 200%, which could result in overgrazing of these increasingly small “isolated” areas. If reindeer, easily able to walk across a road, behaviorally prefer to avoid roads, what are the effects of such developments on smaller animals, vertebrates and invertebrates, that are less capable of crossing such obstacles? This indicates that arctic habitats must be of large extent if they are to preserve the range of species associated with such habitats. How large should habitats be? Two developments 8 km apart, on the basis of Nellemann et al.’s research, can only accommodate 8% of the wild reindeer density (using winter data), and so developments will have to be more distant from each other if there is not to be undue pressure on the reindeer population and the habitats into which they move. Nellemann et al.’s conclusion was that the impacts of development in the Arctic extend for 4 to 10 km from the infrastructure. So, two developments separated by 20 km may leave no land unimpacted. Developments must therefore be carefully planned, widely separated, and without the fragmentation of habitats by roads, trails, power lines, or holiday cabins. As well as potential impacts from development, habitats will change with a changing climate. An example of where this is important for tourism is in the Denali National Park, the most visited national park in Alaska. Bus tours provide the main visitor experience by providing viewing of wildlife and scenery along the park road. The Denali park road begins in boreal forest at the park headquarters and extends through treeline into broad expanses of tundra offering long vistas. Climate-driven changes in the position of forest versus tundra would have significant effects on the park by changing the suitability of certain areas for these experiences. A treegrowth model for the park has been developed based on landscape characteristics most likely to support trees with positive growth responses to warming versus landscapes most likely to support trees with negative responses.The results were projected into the 21st century using data from the five general circulation models climate scenarios used in the ACIA analysis. The scenarios project climates that will cause dieback of white spruce at low elevations and treeline advance and infilling at high elevations. The net effect of tree changes is projected to be a forest increase of about 50% along the road corridor, thus decreasing the possibility for viewing scenery and wildlife at one of the most important tourist sites in Alaska. The maps of potential forest dieback and expansion should be useful for future planning.
Developments have two important implications for conservation, and both can potentially be implemented a priori. First, what regulations are needed to reduce environmental risks? A study for the Hudson Bay area of Canada provided possible mechanisms for safeguarding local communities, biodiversity, and the environment, while not totally restricting development. Second, how can competing interests be reconciled? Muir advocated forms of integrated management, although stating that such “approaches to integrated management which reconcile economic and conservation values will be complex and consultative”. There is a need for biodiversity conservation interests to form an integral part of any consultations over the use of the marine, coastal, freshwater, and terrestrial resources of the Arctic.
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