Human Activity In Cold Environments

The tradional economic activity of the indigenous population of the tundra was hunting and fishing. In the north of North America, the main activity of the Inuit was hunting seals, which provided them with meat, oil and skins. Fishing (including whales) was a major activity. Some groups occasionally hunted polar bears and smaller mammal.

Mobility was a key to thier contiuned existence. Sledges were pulled by teams of dogs over the icey areas; kayaks, and sometimes larger boats were used on water. The number of Inuit was always small in terms of the vast area in which they lived, so very little pressure was put on the environment, which remained relatively undisturbed.

In the north of Europe, the Sami followed the seasonal movements of herds of wild reindeer that provided them with most of the food & materials that they needed. Fishing was used to supplement thier diet. Reindeer spend most of the winter period in boreal forests living on tree mosses and bark. They move back into the tundra during the summer. Like Inuit, the Lapps lived in an environment that provided all that they needed but could only support low-densisty populations.

The way of lives these have both adopted are totally sustainable.

From the 17th century onwards, the resources of tundra areas began to be expolited by outsiders.

The major forms of economic activity that occured included: sealing, whaling, trapping for fur, and mining particulary for gold. Mining led to the establishment of permanent settlements whereas for other activites tended to be seasonal or temporary.

In the last 100 years or so, exploitation of the tundra has been on a much larger scale and has had a dramatic impact on the lifestyle of the indigenous populations. Activites include mining (particulary for oil), production of electric power, fishing and tourism. Military, strategic and geopolitical concerns have given these areas increasing importance, particulary in Alaska and northern Russia.

Strategic intrest in the northern areas of North America dates back to the 2nd World War. With the treat of Japanese invasion, the USA constructed the Alaskan Highway, which runs northwest of Dawson Creek in Canada to Fairbanks in Alaska. The purpose was to carry heavy weapons to the north. The rise of the USSR after the 2nd World War, and the beginning of the Cold War, increased the strategic significance of Alaska and northern Canada. Such is the involvement of the armed forces that military personnel have, at times, at least 25% of the population of Alaska. Numerous roads, air force bases, radar, and early warning stations have been built. However the military presence has led to little permanent settlement beyond the main bases, which are maintained from outside and are not dependent on local resources.

The physical environment has an undoubted impact on human activites. In turn, human activites in such cold regions can have a great impact on the physical environment. The harsh conditions of cold environments present a challenge for human occupation and development, these conditions include:

• very low temperatures
• short summers and therefore short growing seasons
• low percipitation
• thin, stony, poorly developed soils
• permafrost
• surface thawing in the summer leading to waterlogging
• snow lying for long periods
• blizzards.

Indigenous peoples have adapted thier ways of life to cope with the climate and to make the most out of the limited resources. Establishing permanent settlements and developing activites such as mining has required major technical advances, primarily because the permafrost creates a unique set of problems for construction work and engineering.

Problems are caused when vegetation is cleared from the ground surface. This reduces instulation and results, in summer, in the deepening of the active layer. Even minor disturbances, such as vehicle tracks, can greatly increase the melting, because the vegetation is very slow to re-establish itself.

Buildings speed up the process by spreading heat into the ground. The thawing of the ice leads to the development of thermokarst, a landscape of topographic depressions characterised by extensivei areas of irregular, hummocky ground interspersed with waterlogged hollows. The damage caused by this form of ground subsidence can be seen in tilted and fractured older buildings and in damage to roads, railways and airfeild runways.

In recent years, many new methods of construction have been employed to protect the permafrost and prevent subsidence. Although they are successful, these methods are more expensive than conventional construction, adding to the costs of living in the region and continual maintainence is often necessary. Some of the methods include the following:

• smaller building, such as houses, can be elevated above the ground on piles driven into the permafrost. The gap below the building allows the air to circulate and remove heat that would otherwise will be conducted into the ground.
• larger structures can be built upon aggregate pads, which are layers of coarse sand and gravel. 1-2m thick. This substitutes the insulating effect of vegetation and reduces the transfer of heat from building to ground. These pads can also be placed beneath roads, railways, and landing strips.
• in large settlements ultilidors have been built. A ultilidor is an isulated box, elevated above the ground that carries water supplies, heating pipes and sewers between buildings. Pipes cannot be buried underground because of damage that would be caused by freezing and thawing in the upper soil levels.

Apaprt from the production of thermokarst, human impacts on thr physical environment also include:

• fishing- over-exploitation
• transport-risks of spillages, road vehicles, damaging the ground
• tourism- vegetation removal, litter and waste not easily degraded
• general air pollution

These factors add to the effects of global warming, melting the snow and ice of the region.

Much of the Arctic tundra and Antartica typifiy the common perception of wild and nautral places. Thier remoteness and the extremes of physical processes keep them inaccessible to mass tourism and the excesses of economic development. Conservationists believe wilderness areas have intrinsic value and posses outstanding qualities that are worth conserving for the future. Areas such as these have an aesthetic value for people seeking spiritual refreshment and contemplation. Scientifically they are important because:

• there is need to maintain the gene pool of wild organisms to ensure that genetic variety is maintained
• animal communities can be studied in thier natural environment in such regions
• wilderness is a natural laboratory for the scientific study of ecosystems
• there is a need for pure natural systems to be used as a yardstick against which managed or mismanaged systems can be compared.

There are good reasons for conserving wilderness regions, but they often also contain a range of exploitable resources. Pressure for the development of these resources comes from national and transnational groups that require both energy sources and raw materials to support industrial growth. Balancing developmental pressures against the need to conserve the essential values of wilderness is the increasingly difficult task of management. Sustainable development has an important role to play here but there is disagreement about how it may be successfully applied in many wilderness environments.

In 1964, the Wilderness Act in the USA designated a number of wilderness areas. The largest number of designated areas in any state is in Alaska, which instituted its own wilderness leglislation, the National Interest Lands Conservation Act, in 1980.

The tundra, because of its climate and limited productivity is considered to be a fragile environment. There are a number of reasons for this.

The slow rate of plant growth means that any disruption to the ecosystem takes a long timr to be corrected. Some scientists estimate that it could take over 50 years to return a area of tundra to its former state after interference. The low productivity and limited species diversity mean that plants are very specialised and any disruption causes difficulty in adapting to a changed environment.

Wide fluctuations occur in the amount of energy held in each throphic level of food chains because popuation numbers change rapidly. For example, variations in the number of lemmings and arctic hares, both of which are liable to short term and long term fluctuations, have consquences for the populations of their predators, such as arctic foxes and snowy owls.

Disruptions to the functioning of the biome has long term implications. This is why there has been so much concern over the proposed expliotation of resources such as oil reserves of North Alaska that fall within the Arctic National Wildlife Refuge.