The K?ppen climate classification is one of the most widely used climate classification systems. It was developed by Wladamir K?ppen, a German climatologist, around 1900 (with several further modifications by himself, notably in 1918 and 1936). It is based on the concept that native vegetation is the best expression of climate, thus climate zone boundaries have been selected with vegetation distribution in mind. It combines average annual and monthly temperatures and precipitation, and the seasonality of precipitation.
Group E in the classification represents subarctic climates. In the original scheme, this group was not further divided; later, the designations EO and EC were created, with EO (maritime subarctic) signifying that the coldest month averages above −10 °C, while EC (continental subarctic or boreal subarctic climate) means that at least one month has an average temperature of −10 °C or below.
The subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Canada and Siberia, the north of Scandinavia, northern Mongolia and the extreme north of Heilongjiang.
In most subarctic climates, precipitation tends to be low due to the low moisture content of the cold air. Typically, there is a summer maximum in precipitation ranging from moderate in North America to extreme in the Russian Far East. Except in the wettest areas, glaciers are largely absent because of the lack of winter precipitation, in the wettest areas, however, glaciers tend to be very abundant. 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.
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 herb land dominated by grasses and sedges. Typically, there are only a few species of large mammals in the boreal subarctic climate regions, the most important being moose, reindeer and the wolf. 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, cobalt, lead, zinc and (since the 1940s) uranium.
Except for a few parts of Europe where the winters are relatively mild due to the Gulf Stream, subarctic regions were not explored until the eighteenth and nineteenth centuries. Even then, the difficulty of transportation ensured that few lasted long - the ghost towns of the Yukon, Northwest Territories and increasingly Siberia illustrate this. The Trans-Siberian Railway, which skirts the edge of the region, provided a major boost to Russian settlement in the subarctic.
Tourism in recent years has become a major source of revenue for most countries of the subarctic due to the beautiful, generally glacial, landscapes so characteristic of the region. Most areas in the subarctic are among the most expensive places in the world to visit, due to both high costs of living and extreme difficulties of transport. Nonetheless, the great opportunities for outdoor recreation lure an ever-increasing number of travelers.