Changing Arctic and Adaptation
Polar Bear | Animals | Plants | Reindeers in a Changing Climate | More information
Arctic living conditions are characterized by a low amount of sunlight during winter and long days during summer. This variation in solar input affects significantly all forms of life in circumpolar areas. In spite of the harsh climate, biodiversity in the Arctic areas is relatively great. However, large- scale changes such as global warming are already having visible effects on Arctic nature and many species are obliged to adapt to these changes.
Polar bear (Ursus maritimus ) is one of the Arctic species affected by global climate warming. The thinning of Arctic sea ice threatens the main natural habitat of the polar bear, which hunts ringed seals as its primary prey. Changes in prey conditions and ice coverage are likely to have an effect on nutrient supply and movement of the polar bear. A change in snow cover will have an impact on denning conditions. It is predicted that polar bears are unlikely to survive if the summer sea ice cover is completely lost.
In addition to its conservational value, the polar bear is economically important for Arctic peoples.
Animals and plants use different adaptation mechanisms to adjust to cold and dark. Species staying year-round in the Arctic have a thick layer of fur, blubber or feathers to stay warm. Animals also store fat before winter and seek shelter from snow to protect them from the cold. Migratory birds are present in the Arctic during the summer months when there is enough food and sunlight. Physiological and morphological factors in mammals and birds such as metabolic seasonal adjustments, change of color, high body growth rate, and short appendages are common features. Some animals hibernate in order to survive over the cold and long winter.
Individuals of the species react to changes in climate over a wide range of time scales varying from quick responses (i.e. behavioral processes) to slow integrative responses (i.e. in reproduction). Conditional changes such as higher summer temperatures, changes in migration routes, and altered snow and ice conditions are likely to affect the living conditions of Arctic animals.
Plants use the long hours of sunlight effectively during the short growing season. Physiological features such as low structure and cup-shaped flowers enable plants to utilize energy from sunlight during the summer. Fuzzy coverings on the stems, buds and leaves protect plants from the wind. Most of the plants in the Arctic are perennial so they do not die during the long winter.
Many of the Arctic plants are pre-adapted. This limits their responses to climate warming and other environmental changes. Most likely plants will change their distribution when the global climate warms. On a larger scale, vegetation zones are very likely to shift northward.
Overall, Arctic plants and animals are expected to relocate themselves as a primary response to climate change, provided that access is unhindered by anthropogenic or natural barriers.
Reindeers in a Changing Climate
During the recent years, availability of reindeer winter forage has deteriorated due to changing winter climate. Consequences of extreme weathers, such as ice layer formed on the surface of the snowless soil and vegetation or within the snow cover and/or exceptionally thick snow cover have aggravated digging conditions of reindeer and availability of forage. This has a clear connection to the calf percentage of the next summer, mortality rate of calves and the weight of calves in the fall via the state of the dams. Supplementary feeding will secure the survival of reindeer during winters with exceptional weather conditions (emergency feeding), make herding easier, and to keep reindeer in certain district and to keep their number and status stable. Supplementary feeding also reduces grazing pressure. Feeding can be done principally by two ways: by taking forage to the field and by keeping reindeer in domestic farms during the winter.
More information on this topic is availabe from the Arctic Centre’s research project Reindeer Forage and Supplementary Feeding in a Changing Climate.
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