### Taiga or Coniferous Forest

Introduction.The taiga or boreal forest exists as a nearly continuous belt of coniferous trees across North America and Eurasia. Overlying formerly glaciated areas and areas of patchy permafrost on both continents, the forest is mosaic of successional and subclimax plant communities sensitive to varying environmental conditions. Taiga is the Russian name for this forest which covers so much of that country. However, the term is used in North America as well.

Climate: The taiga corresponds with regions of subarctic and cold continental climate. Long, severe winters and short summers are characteristic, as is a wide range of temperatures between the lows of winter and highs of summer. For example, Verkhoyansk, Russia, has recorded extremes of minus 90 ° Fand plus 90 ° F. Mean annual precipitation is 15 to 20 inches, but low evaporation rates make this a humid climate.

Vegetation: Needleleaf, coniferous trees are the dominant plants of the taiga biome. A very few species in four main genera are found: the evergreen spruce, fir, and pine, and the deciduous larch or tamarack. In North America, one or two species of fir and one or two species of spruce are dominant. Across Scandanavia and western Russia the Scots pine is a common component of the taiga.

Soil: Podzolization occurs as a result of the acid soil solution produced under needleleaf trees. The main soil order associated with the taiga is spodosol.

Fauna: Fur-bearing predators like the lynx and various members of the weasel family (e.g., wolverine, fisher, pine martin, mink, ermine, and sable) are perhaps most characteristic of the boreal forest proper. The mammalian herbivores on which they feed include the snowshoe or varying hare, red squirrel, lemmings, and voles.
Large herbivores are more closely associated with successional stages where there is more nutritious browse available and include elk or wapiti and moose. The beaver, on which the early North American fur trade was based, is also a creature of early successional communities, indeed its dams along streams create such habitats.
Among birds, insect-eaters like the wood warblers are migratory and leave after the breeding season. Seed-eaters (e.g., finches and sparrows) and omnivores (e.g., ravens) tend to be year-round residents. During poor cone years, normal residents like the evening grosbeak, pine siskin, and red crossbill leave the taiga in winter and may be seen at bird feeders here in Virginia.