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subarctic
The subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Shetland Islands. Generally, subarctic regions fall between 50°N and 70°N latitude, depending on local climates.
== Climate and soils ==
Monthly temperatures are above for at least one and at most three months of the year. Precipitation tends to be low due to the low moisture content of the cold air. Precipitation is typically greater in warmer months, with a summer maximum ranging from moderate in North America to extreme in the Russian Far East. Except in the wettest areas glaciers are not large because of the lack of winter precipitation; in the wettest areas, however, glaciers tend to be very abundant and Pleistocene glaciation covered even the lowest elevations. Soils of the subarctic are generally very acidic largely because of the influence of the vegetation both in the taiga and in peaty bogs, which tends to acidify the soil, as well as the extreme ease with which leaching of nutrients takes place even in the most heavily glaciated regions. The dominant soil orders are podsols and further north gelisols.
Subarctic regions are often characterized by taiga forest vegetation, though where winters are relatively mild, as in northern Norway, broadleaf forest may occur—though in some cases soils remain too saturated almost throughout the year to sustain ''any'' tree growth and the dominant vegetation is a peaty herbland dominated by grasses and sedges. Typically, there are only a few species of large terrestrial mammals in the subarctic regions, the most important being elk, moose (''Alces alces''), bears, reindeer (''Rangifer tarandus''), and wolves (''Canis lupus''). Agriculture is mainly limited to animal husbandry, though in some areas barley can be grown. Canada and Siberia are very rich in minerals, notably nickel, molybdenum, cobalt, lead, zinc and uranium, whilst the Grand Banks and Sea of Okhotsk are two of the richest fisheries in the world and provide support for many small towns.
Except for those areas adjacent to warm ocean currents, there is almost always continuous permafrost due to the very cold winters. This means that building in most subarctic regions is very difficult and expensive: cities are very few (Murmansk being the largest) and generally small, whilst roads are few. Subarctic rail transport only exists in Europe (lines to Narvik and Murmansk) and the Norilsk–Dudinka line in northern Siberia. An important consequence is that transportation tends to be restricted to "bush" planes, helicopters and, in summer, riverboats.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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