Origin

Nowadays, Boreal forests cover about 17% of the world's land surface, spreading across North America and Eurasia inside the northern circumpolar regions.

History

During the last ice age, species that now compose the Taiga were forced out to the south by continental glaciers of Europe, Asia and North America. When the glaciers started to retreat sometime around 18,000 years ago, the same species that were displaced began to move back northward in Europe and North America. This movement was relatively steady and gradual. And because at that time sea levels were much lower than what they are today, it allowed various terrestrial species such as plants and animals to migrate much easier from one region to another.

Distribution

The Boreal forest regions spread across the regions of Eurasia and North America, from Atlantic to Pacific coasts respectively. In Asia, the Taiga covers most of Russia's territory, as well as the northern parts of Mongolia and China. In North America, Boreal forests extends across most of Canada and Alaska, and stops north of the southern border of Canada. In Europe, we can find Boreal Forests in Finland, Sweden and Norway, as well as in a small area in the Scottish Highlands.

Environmental Conditions

By being located in the northern parts of our planet, Boreal forests has specific environmental conditions that influence their biome and ecosystem.

Climate

As one can imagine, the most dominant weather pattern in Boreal forests is a cold climate, even though a diversity of climates can be found. The solar elevation angle, day length, and snow cover are the main factors that produce this cold climate. Unlike in the tropics, the Sun is never directly overhead in the Taiga. The more north we are, the more the maximum solar angle decreases. As a result, the energy Boreal forests receive from the Sun is less intense than in equatorial regions because it is spread out over a greater area of Earth’s surface. Furthermore, long winter nights (as it exists in Boreal regions) affects temperatures as radiation emitted by the Earth's surface escape into the atmosphere. Lastly, the snow cover of the Taiga reflects the solar radiation and increases cooling.

Human Impact

The human factor and forest management in different countries and regions have had various impact on the Taiga. In Scandinavia, countries have a highly developed forest industry. In this region, at least 95% of the Boreal forests have been harvested at lease once, and in Finland, about 9% of the land is protected from human modification. The Taiga of Siberia accounts for about 19% of the planet's forested area. In this region, about 400,000 hectares of the forests are logged annually, and nearly an equal area is burned, with half of it being the result of destructive fires from human origin. In Canada and Alaska, considerable efforts are being carried out to protect and reforest large areas. About 18% of Canada's primary forests remain unlogged, and about 40% of Alaska's Taiga is under strict protection of natural habitats and species.

Ecosystem

There are fewer species in Boreal forests than in any other type of forest in the world. This is in accordance with the observation that there is fewer diversity in higher latitudes than in lower latitudes.

Trees

The majority of tree species in Boreal forests are are well adapted to cold winter climate. The Taiga is composed primarily of cone-bearing or evergreen trees and is characterized by a limited number of conifer species. We mainly find pines (Pinus), spruces (Picea), larches (Larix), firs (Abies) and to a lesser degree birches (Betula) and poplars (Populus). These trees reach the highest latitudes of any trees on the planet.

Other Plants

A distinctive feature of the Taiga is the abundance and diversity of mosses. About 1/3 of the ground of Boreal forests is covered by moss. Lichens constitute another significant part of the ground cover in the Taiga, and because both lichens and mosses are dispersed by airborne spores, many species of both groups are found across the entire circumpolar taiga as they travel great distances.
On another hand, Boreal forests are a berry paradise. One can easily find in abundance many different types of berries. Blueberries, bog bilberries, lingonberries, crowberries or the famous cloudberries are amongst the most popular one can encounter wandering in the forest.
Furthermore, specialized orchids in the Taiga include calypso (Calypso bulbosa), coralroot (Corallorrhiza trifida), and lady’s slipper (Cypripedum species). Lastly, there is a wide range of fungus-like organisms that populate the grounds of Boreal forests.

Animals

The Taiga is quite a peaceful environment when it comes to wildlife compared to other types of forests. Only a few predators dominate these regions: brown bears, wolves, wolverines and lynxes. Other than that, foxes, elks, reindeers, hares, squirrels and stouts constitute the rest of the mammals populating the Taiga.
Boreal forests are the migratory destination of large numbers of birds for the summer breeding season. Amonst them are several songbirds typical of shrub and forest habitats, such as thrushes, flycatchers, and warblers. Predators of these birds can also be found in the forest as well, such as the sharp-shinned hawk (Accipiter striatus) and the northern goshawk (A. gentilis). Because of limited opportunities for food, most bird species of the Taiga migrate during the long cold winters, although some undertake only a short trip to the south. The extensive areas of lakes, ponds, and wetlands provide a large habitat for waterfowl and shorebirds such as the common snipe (Gallinago gallinago) and yellowlegs (Tringa species).