TAIGA The Boreal Forest

1. TAIGA The Boreal Forest

2. Taiga Facts • “Taiga” comes from the Russian word for forest • The taiga is the largest biome in the world • The forests within the Mat-Su valley are classified as taiga • The names ‘boreal forest’ or ‘northern forest’ are sometimes used in place of ‘taiga’ • Did you know that ‘boreal’ comes from the name of the Greek goddess of the North Wind?

3. Introduction to the Taiga • The Taiga exists a nearly continuous belt of coniferous trees across North America, Europe and Asia • Since it is growing in areas that were formerly glaciated, and there is patches of permafrost, there is a variety of successional stages that can be found. • This is called a ‘forest mosaic’

4. Climate • Long, severe winters (up to six months with mean temperatures below freezing) and short summers (50 to 100 frost-free days) • Mean annual precipitation is 15 to 20 inches, but low evaporation rates make this a humid climate • Conditions are similar to the tundra, just a little less extreme

5. Geography • There are many water bodies found within the boreal forest: • Bogs, fens, marshes, shallow lakes, rivers and wetlands • Forests cover approximately 19.2 million square miles - (33%) of the world's land surface area, and boreal forests cover about 6.4 million square miles, or 1/3 of all the forests

6. More geography • There are latitudinal zones within the boreal forest. • tundra/taiga ecotone • an open coniferous forest (the section most properly called taiga) • and a mixed needleleaf evergreen-broadleaf deciduous forest, the ecotone with the Temperate Broadleaf Deciduous Forest

7. Taiga Soils • Soils in this forest are called podzols, from the Russian word for ash (the color of these soils) • Podzolization occurs as a result of the acid soil solution produced under needleleaf trees. • This means that iron and aluminum are leached from the surface, and deposited in lower layers • Clays and other minerals migrate to lower layers, leaving the upper one sandy in texture

8. Taiga Trees • By far the most dominant tree species are conifers • well-adapted to the harsh climate, and thin, acidic soils • Four main genera found in the taiga • spruce (Picea) • fir (Abies) • pine (Pinus) • and the deciduous larch or tamarack (Larix).

9. Taiga Trees • Broadleaf deciduous trees and shrubs are found in early successional stages • Most common are alder (Alnus), birch (Betula), and aspen (Populus) and willow (Salix). There are also many varieties of berries and low lying plants that are very important to the balance of the ecosystem.

10. But why so many evergreens? • Conical shape • promotes shedding of snow and prevents loss of branches. • Needleleaf • narrowness reduces surface area through which water may be lost (transpired), • the needles of boreal conifers also have thick waxy coatings which protected from drying winds. • Evergreen habit • retention of foliage allows plants to photosynthesize as soon as temperatures permit in spring, rather than having to waste time and energy growing leaves • Dark color • the dark green of spruce and fir needles helps the foliage absorb maximum heat from the sun and begin photosynthesis as early as possible

11. Taiga Animals • The North American boreal forest offers breeding grounds to over 200 bird species, as well as being home to species such as Lynx, Black Bear, Moose, Coyote and Timber Wolf

12. Taiga Animals • Since most of the trees have cones, there are animals that have evolved adaptations to obtain seeds from the cones • Conversely, the trees have adaptations to deter this, usually spines on the cones. • Crossbills (which have crossed beaks) are highly efficient seed extractors.

13. Moose are common large herbivores in the boreal forest. Caribou use the forest for shelter in the worst parts of the winter. Moose (Alces alces) generally prefer deciduous browse and herbaceous plants, while caribou (Rangifer terrendus) scavenge for lichens and can eat conifer needles. Thus, the two large herbivores have different food requirements - moose being an early successional (young forest) species, and caribou a late successional (older forest) species. Taiga Animals

14. Taiga Animals • The beaver (Castor canadensis), 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.

15. Taiga Animals • Bear (Ursus) are abundant in the boreal forest, along with wolves (Canis lupus). • Snowshoe hares (Lepus americanus) and lynx (Felis lynx), which have unusually large feet to walk across snow, are also common.

16. Taiga Animals • Various members of the weasel family (e.g., wolverine, fisher, pine martin, mink, ermine, and sable) are extremely characteristic of the boreal forest.

17. Taiga Animals • Among birds, insect-eaters like the wood warblers are migratory and leave after the breeding season. • Seed-eaters (finches, grosbeaks, sparrows and chickadees) and omnivores (e.g., ravens) tend to be year-round residents. • During poor cone years, these year-round residents may leave the taiga in winter and can be seen at residential bird feeders.

18. To sum it all up… • The taiga is sometimes called the boreal forest. • Conditions are similar to the tundra (as far as temperatures, sunlight, etc) but not quite as extreme • The dominant vegetation is needle-leafed trees. • There is a variety of wildlife—much greater biodiversity than the tundra • We live in the taiga!