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88-519: The Squamish River drains a complex of basins in the Coast Mountains just north of Vancouver . Its flows generally south to the head of Howe Sound where the town of Squamish is located. The Squamish River originates at the toe of the Pemberton Icefield . As it flows south from the glacier , it is joined by several more glacier fed tributaries. About 21.8 km southwest of the source,

176-412: A fire regime to burn an area equivalent to the total area of an ecosystem is its fire rotation (Heinselman 1973) or fire cycle (Van Wagner 1978). However, as Heinselman (1981) noted, each physiographic site tends to have its own return interval, so that some areas are skipped for long periods, while others might burn two-times or more often during a nominal fire rotation. The dominant fire regime in

264-676: A large mass of igneous rock , creating a new continental margin. This large mass of igneous rock is the largest granite outcropping in North America. The final event began when the Farallon Plate continued to subduct under the new continental margin after the Insular Plate and Insular Islands collided with the old continental margin, supporting a new continental volcanic arc called the Coast Range Arc about 100 million years ago during

352-687: A major mountain range in the Pacific Coast Ranges of western North America , extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River . The mountain range's name derives from its proximity to the sea coast, and it is often referred to as the Coast Range . The range includes volcanic and non-volcanic mountains and

440-454: A number of adaptations specifically for survival in harsh taiga winters, although larch, which is extremely cold-tolerant, is deciduous . Taiga trees tend to have shallow roots to take advantage of the thin soils, while many of them seasonally alter their biochemistry to make them more resistant to freezing, called "hardening". The narrow conical shape of northern conifers, and their downward-drooping limbs, also help them shed snow. Because

528-484: A patch of sun; mosses and lichens thrive on the damp ground and on the sides of tree trunks. In comparison with other biomes, however, the taiga has low botanical diversity. Coniferous trees are the dominant plants of the taiga biome. Very few species, in four main genera, are found: the evergreen spruce, fir and pine, and the deciduous larch. In North America, one or two species of fir, and one or two species of spruce, are dominant. Across Scandinavia and western Russia,

616-550: A polar species, some southern herds of muskoxen reside in the taiga of Russia's Far East and North America. The Amur -Kamchatka region of far eastern Russia also supports the snow sheep , the Russian relative of the American bighorn sheep , wild boar , and long-tailed goral . The largest animal in the taiga is the wood bison of northern Canada/Alaska; additionally, some numbers of the American plains bison have been introduced into

704-525: A pre-existing continental margin and coastline of North America. These volcanic islands, known as the Insular Islands by geoscientists, were formed on a pre-existing tectonic plate called the Insular Plate by subduction of the former Farallon Plate to the west during the early Paleozoic era. This subduction zone records another subduction zone to the east under an ancient ocean basin between

792-408: A relatively small variety of highly specialized and adapted animals, due to the harshness of the climate. Canada's boreal forest includes 85 species of mammals , 130 species of fish, and an estimated 32,000 species of insects . Insects play a critical role as pollinators , decomposers , and as a part of the food web. Many nesting birds, rodents, and small carnivorous mammals rely on them for food in

880-412: A warmer climate. The mature boreal forest pattern in the south shows balsam fir dominant on well-drained sites in eastern Canada changing centrally and westward to a prominence of white spruce , with black spruce and tamarack forming the forests on peats, and with jack pine usually present on dry sites except in the extreme east, where it is absent. The effects of fires are inextricably woven into

968-535: Is a biome characterized by coniferous forests consisting mostly of pines , spruces , and larches . The taiga or boreal forest is the world's largest land biome . In North America, it covers most of inland Canada , Alaska , and parts of the northern contiguous United States. In Eurasia , it covers most of Sweden , Finland , much of Russia from Karelia in the west to the Pacific Ocean (including much of Siberia ), much of Norway and Estonia , some of

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1056-472: Is associated with the Norrland terrain . After the permanent ice caps and tundra , taiga is the terrestrial biome with the lowest annual average temperatures, with mean annual temperature generally varying from −5 to 5 °C (23 to 41 °F). Extreme winter minimums in the northern taiga are typically lower than those of the tundra. There are taiga areas of eastern Siberia and interior Alaska- Yukon where

1144-555: Is found in areas with mean annual temperature below freezing, whilst in the Dfd and Dwd climate zones continuous permafrost occurs and restricts growth to very shallow-rooted trees like Siberian larch . The growing season , when the vegetation in the taiga comes alive, is usually slightly longer than the climatic definition of summer as the plants of the boreal biome have a lower temperature threshold to trigger growth than other plants. Some sources claim 130 days growing season as typical for

1232-409: Is found in the smaller areas with oceanic influences; in coastal areas of Scandinavia and Finland, the growing season of the closed boreal forest can be 145–180 days. The shortest growing season is found at the northern taiga–tundra ecotone , where the northern taiga forest no longer can grow and the tundra dominates the landscape when the growing season is down to 50–70 days, and the 24-hr average of

1320-427: Is further evidence pointing to a long and intimate association with fire. Seven of the ten most common trees in the boreal forest— jack pine , lodgepole pine , aspen , balsam poplar ( Populus balsamifera ), paper birch , tamarack , black spruce – can be classed as pioneers in their adaptations for rapid invasion of open areas. White spruce shows some pioneering abilities, too, but is less able than black spruce and

1408-554: Is home to many types of berries . Some species are confined to the southern and middle closed-boreal forest (such as wild strawberry and partridgeberry ); others grow in most areas of the taiga (such as cranberry and cloudberry ). Some berries can grow in both the taiga and the lower arctic (southern regions) tundra, such as bilberry , bunchberry and lingonberry . The forests of the taiga are largely coniferous , dominated by larch , spruce , fir and pine . The woodland mix varies according to geography and climate; for example,

1496-416: Is not a limiting factor, the ground freezes during the winter months and plant roots are unable to absorb water, so desiccation can be a severe problem in late winter for evergreens. Although the taiga is dominated by coniferous forests, some broadleaf trees also occur, including birch , aspen , willow , and rowan . Many smaller herbaceous plants, such as ferns and occasionally ramps grow closer to

1584-520: Is not exclusively an alpine biome, and unlike subalpine forest , much of taiga is lowlands. The term "taiga" is not used consistently by all cultures. In the English language, "boreal forest" is used in the United States and Canada in referring to more southerly regions, while "taiga" is used to describe the more northern, barren areas approaching the tree line and the tundra . Hoffman (1958) discusses

1672-543: The Bering land bridge , a number of animal and plant species , more animals than plants, were able to colonize both land masses, and are globally-distributed throughout the taiga biome (see Circumboreal Region ). Others differ regionally, typically with each genus having several distinct species, each occupying different regions of the taiga. Taigas also have some small-leaved deciduous trees, like birch , alder , willow , and poplar . These grow mostly in areas further south of

1760-724: The British Columbia Interior from the Pacific weather systems, resulting in dry warm summers and dry cold winters. Beyond the eastern slopes is a 154,635 km (59,705 sq mi) plateau occupying the southern and central portions of British Columbia called the Interior Plateau . Included within the Interior Plateau is a coalescing series of layered flood basalt lava flows. These sequences of fluid volcanic rock cover about 25,000 km (9,700 sq mi) of

1848-668: The Eastern Canadian forests ecoregion (of the higher elevations of the Laurentian Mountains and the northern Appalachian Mountains ) in Canada is dominated by balsam fir Abies balsamea , while further north, the Eastern Canadian Shield taiga (of northern Quebec and Labrador ) is mostly black spruce Picea mariana and tamarack larch Larix laricina . Evergreen species in the taiga (spruce, fir, and pine) have

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1936-667: The Fraser River and the Interior Plateau while its far northwestern edge is delimited by the Kelsall and Tatshenshini Rivers at the north end of the Alaska Panhandle, beyond which are the Saint Elias Mountains, and by Champagne Pass in the Yukon Territory . Covered in dense temperate rainforest on its western exposures, the range rises to heavily glaciated peaks, including the largest temperate-latitude ice fields in

2024-655: The Late Cretaceous period. Magma rising from the Farallon Plate under the new continental margin ascended through the newly accreted Insular Belt, injecting huge quantities of granite into older igneous rocks of the Insular Belt. At the surface, new volcanoes were built along the continental margin. Named after the Coast Mountains, the basement of this arc was likely Early Cretaceous and Late Jurassic intrusions from

2112-529: The Mamquam River . From there, the river flows another 6 km to its mouth at the head of the Howe Sound. The Skwelwil'em Squamish Estuary Wildlife Management Area is located at the river mouth. This article about a river in the Coast of British Columbia , Canada is a stub . You can help Misplaced Pages by expanding it . Coast Mountains The Coast Mountains ( French : La chaîne Côtière ) are

2200-726: The Saint Elias Mountains and the Chugach Mountains . The Coast Mountains are also part of the American Cordillera —a Spanish term for an extensive chain of mountain ranges—that consists of an almost continuous sequence of mountain ranges that form the western backbone of North America , Central America , South America and Antarctica . The Coast Mountains are approximately 1,600 kilometres (1,000 mi) long and average 300 kilometres (190 mi) in width. The range's southern and southeastern boundaries are surrounded by

2288-606: The Scots pine is a common component of the taiga, while taiga of the Russian Far East and Mongolia is dominated by larch . Rich in spruce and Scots pine (in the western Siberian plain), the taiga is dominated by larch in Eastern Siberia, before returning to its original floristic richness on the Pacific shores. Two deciduous trees mingle throughout southern Siberia: birch and Populus tremula . The boreal forest/taiga supports

2376-549: The Scottish Highlands , some lowland/coastal areas of Iceland , and areas of northern Kazakhstan , northern Mongolia , and northern Japan (on the island of Hokkaidō ). The principal tree species, depending on the length of the growing season and summer temperatures, vary across the world. The taiga of North America is mostly spruce; Scandinavian and Finnish taiga consists of a mix of spruce , pines and birch ; Russian taiga has spruces, pines and larches depending on

2464-644: The Stikine Icecap , which lies between the lower Stikine River and the Whiting River . Because the Coast Mountains are just east of the Pacific Ocean , they have a profound effect on British Columbia's climate by forcing moisture-laden air off the Pacific Ocean to rise, dropping heavy rainfalls on the western slopes where lush forests exist. This precipitation is among the heaviest in North America. The eastern slopes are relatively dry and less steep and protect

2552-419: The golden eagle , rough-legged buzzard (also known as the rough-legged hawk), Steller's sea eagle (in coastal northeastern Russia-Japan), great gray owl , snowy owl , barred owl , great horned owl , crow and raven . The only other viable adaptation is seed-eating birds, which include several species of grouse , capercaillie and crossbills . Fire has been one of the most important factors shaping

2640-445: The middle boreal (closed forest), and the southern boreal , a closed-canopy, boreal forest with some scattered temperate, deciduous trees among the conifers. Commonly seen are species such as maple, elm and oak. This southern boreal forest experiences the longest and warmest growing season of the biome. In some regions, including Scandinavia and western Russia, this subzone is commonly used for agricultural purposes. The boreal forest

2728-498: The peatlands . During the last quarter of the twentieth century, the zone of latitude occupied by the boreal forest experienced some of the greatest temperature increases on Earth. Winter temperatures have increased more than summer temperatures. In summer, the daily low temperature has increased more than the daily high temperature. The number of days with extremely cold temperatures (e.g., −20 to −40 °C; −4 to −40 °F) has decreased irregularly but systematically in nearly all

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2816-681: The Bridge River Ocean, the Insular Islands drew closer to the former continental margin and coastline of western North America, supporting a pre-existing volcanic arc on the former continental margin of North America called the Omineca Arc . As the North American Plate drifted west and the Insular Plate drifted east to the old continental margin of western North America, the Bridge River Ocean eventually closed by ongoing subduction under

2904-532: The Bridge River Ocean. This subduction zone eventually jammed and shut down completely 115 million years ago, ending the Omineca Arc and the Insular Islands collided, forming the Insular Belt . Compression resulting from this collision crushed, fractured and folded rocks along the old continental margin. The Insular Belt then welded onto the pre-existing continental margin by magma that eventually cooled to create

2992-632: The Coast Mountains and the highest that lies entirely within British Columbia, located northeast of the head of Knight Inlet with an elevation of 4,019 metres (13,186 ft). The Coast Mountains consists of three subdivisions known as the Pacific Ranges , the Kitimat Ranges , and the Boundary Ranges . The Pacific Ranges are the southernmost subdivision of the Coast Mountains, extending from

3080-506: The Coast Range Arc were then deformed under the heat and pressure of later intrusions, turning them into layered metamorphic rock known as gneiss . In some places, mixtures of older intrusive rocks and the original oceanic rocks have been distorted and warped under intense heat, weight and stress to create unusual swirled patterns known as migmatite , appearing to have been nearly melted in the procedure. Volcanism began to decline along

3168-460: The Cordilleran region, fire is most frequent in the valley bottoms, decreasing upward, as shown by a mosaic of young pioneer pine and broadleaf stands below, and older spruce–fir on the slopes above. Without fire, the boreal forest would become more and more homogeneous, with the long-lived white spruce gradually replacing pine, aspen, balsam poplar, and birch, and perhaps even black spruce, except on

3256-627: The Hudson Bay area), chum salmon , Siberian taimen , lenok and lake chub . The taiga is mainly home to a number of large herbivorous mammals , such as Alces alces ( moose ), and a few subspecies of Rangifer tarandus ( reindeer in Eurasia; caribou in North America). Some areas of the more southern closed boreal forest have populations of other Cervidae species, such as the maral , elk , Sitka black-tailed deer , and roe deer . While normally

3344-559: The Insular Islands and the former continental margin of North America called the Bridge River Ocean . This arrangement of two parallel subduction zones is unusual in that very few twin subduction zones exist on Earth; the Philippine Mobile Belt off the southeastern coast of Asia is an example of a modern twin subduction zone. As the Insular Plate drew closer to the pre-existing continental margin by ongoing subduction under

3432-625: The Insular Islands. One of the major aspects that changed early during the Coast Range Arc was the status of the northern end of the Farallon Plate, a portion now known as the Kula Plate . About 85 million years ago, the Kula Plate broke off from the Farallon Plate to form a mid-ocean ridge known to geoscientists as the Kula-Farallon Ridge . This change apparently had some important ramifications for regional geologic evolution. When this change

3520-604: The Interior Plateau and have a volume of about 1,800 km (430 cu mi), forming a large volcanic plateau constructed atop of the Interior Plateau. North of the Interior Plateau on the range's northeastern slopes lies a huge mountainous area known by geographers as the Interior Mountains , which includes the neighbouring Skeena , Cassiar and Hazelton Mountains . The Coast Mountains consist of deformed igneous and metamorphosed structurally complex pre- Tertiary rocks. These originated in diverse locations around

3608-854: The Nass River in the south to the Kelsall River in the north. It is also the largest subdivision of the Coast Mountains, spanning the British Columbia-Alaska border and northwards into Yukon flanking the west side of the Yukon River drainage as far as Champagne Pass , north of which being the Yukon Ranges . The Boundary Ranges include several large icefields, including the Juneau Icefield between Juneau, Alaska and Atlin Lake in British Columbia, and

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3696-441: The Russian far-east, as part of the taiga regeneration project called Pleistocene Park , in addition to Przewalski's horse . Small mammals of the taiga biome include rodent species such as the beaver , squirrel , chipmunk , marmot , lemming , North American porcupine and vole , as well as a small number of lagomorph species, such as the pika , snowshoe hare and mountain hare . These species have adapted to survive

3784-690: The Squamish meets the Elaho River . The Elaho River, which is the largest tributary of the Squamish, actually has more volume than the Squamish where they join. After its confluence with the Elaho, the river moves southeast for another 24.8 km until its confluence with the Ashlu River , its second largest tributary. Another 16.4 km from there, it is met by the Cheakamus River , and 4.7 km further south, by

3872-440: The boreal forest is high-intensity crown fires or severe surface fires of very large size, often more than 10,000 ha (100 km ), and sometimes more than 400,000 ha (4000 km ). Such fires kill entire stands. Fire rotations in the drier regions of western Canada and Alaska average 50–100 years, shorter than in the moister climates of eastern Canada, where they may average 200 years or more. Fire cycles also tend to be long near

3960-471: The boreal forest, typically with abrupt, irregular boundaries circumscribing homogenous stands, is indirect but compelling testimony to the role of fire in shaping the forest. The fact is that most boreal forest stands are less than 100 years old, and only in the rather few areas that have escaped burning are there stands of white spruce older than 250 years. The prevalence of fire-adaptive morphologic and reproductive characteristics of many boreal plant species

4048-527: The boreal region, allowing better survival for tree-damaging insects. In Fairbanks, Alaska , the length of the frost-free season has increased from 60 to 90 days in the early twentieth century to about 120 days a century later. It has been hypothesized that the boreal environments have only a few states which are stable in the long term - a treeless tundra/steppe, a forest with >75% tree cover and an open woodland with ~20% and ~45% tree cover. Thus, continued climate change would be able to force at least some of

4136-552: The coldest month is between −6 °C (21 °F) and −50 °C (−58 °F). There are also some much smaller areas grading towards the oceanic Cfc climate with milder winters, whilst the extreme south and (in Eurasia) west of the taiga reaches into humid continental climates ( Dfb , Dwb ) with longer summers. According to some sources, the boreal forest grades into a temperate mixed forest when mean annual temperature reaches about 3 °C (37 °F). Discontinuous permafrost

4224-521: The composition and development of boreal forest stands; it is the dominant stand-renewing disturbance through much of the Canadian boreal forest. The fire history that characterizes an ecosystem is its fire regime , which has 3 elements: (1) fire type and intensity (e.g., crown fires, severe surface fires, and light surface fires), (2) size of typical fires of significance, and (3) frequency or return intervals for specific land units. The average time within

4312-480: The dark winters, depending on latitude. The areas of the taiga inside the Arctic Circle have midnight sun in mid-summer and polar night in mid-winter. The taiga experiences relatively low precipitation throughout the year (generally 200–750 mm (7.9–29.5 in) annually, 1,000 mm (39 in) in some areas), primarily as rain during the summer months, but also as snow or fog . Snow may remain on

4400-531: The dense vegetation growth including large trees. This explains the striking difference in biomass per square metre between the Taiga and the Steppe biomes, (in warmer climates), where evapotranspiration exceeds precipitation, restricting vegetation to mostly grasses. In general, taiga grows to the south of the 10 °C (50 °F) July isotherm , occasionally as far north as the 9 °C (48 °F) July isotherm, with

4488-420: The early Eocene period. Volcanism along the entire length of the Coast Range Arc shut down about 50 million years ago and many of the volcanoes have disappeared from erosion. What remains of the Coast Range Arc to this day are outcrops of granite when magma intruded and cooled at depth beneath the volcanoes, forming the present Coast Mountains. During construction of intrusions 70 and 57 million years ago,

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4576-459: The ease with which plants can use its nutrients. The relative lack of deciduous trees, which drop huge volumes of leaves annually, and grazing animals, which contribute significant manure, are also factors. The diversity of soil organisms in the boreal forest is high, comparable to the tropical rainforest . Fallen leaves and moss can remain on the forest floor for a long time in the cool, moist climate, which limits their organic contribution to

4664-884: The extensive ice fields of the Pacific and Boundary Ranges , and the northern end of the volcanic system known as the Cascade Volcanoes . The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range , the Insular Mountains , the Olympic Mountains , the Oregon Coast Range , the California Coast Ranges ,

4752-459: The forest history of an area 280 km north of the then-current tree line at Ennadai Lake, District Keewatin, Northwest Territories. Two lines of evidence support the thesis that fire has always been an integral factor in the boreal forest: (1) direct, eye-witness accounts and forest-fire statistics, and (2) indirect, circumstantial evidence based on the effects of fire, as well as on persisting indicators. The patchwork mosaic of forest stands in

4840-472: The globe: the area is built of several different terranes of different ages with a broad range of tectonic origins. In addition, oceanic crust under the Pacific Ocean is being subducted at the southern portion of the range to form a north–south line of volcanoes called the Garibaldi Volcanic Belt , a northern extension of the Cascade Volcanoes in the northwestern United States , and contains

4928-404: The ground for as long as nine months in the northernmost extensions of the taiga biome. The fog, especially predominant in low-lying areas during and after the thawing of frozen Arctic seas, stops sunshine from getting through to plants even during the long summer days. As evaporation is consequently low for most of the year, annual precipitation exceeds evaporation, and is sufficient to sustain

5016-519: The ground. Periodic stand-replacing wildfires (with return times of between 20 and 200 years) clear out the tree canopies, allowing sunlight to invigorate new growth on the forest floor. For some species, wildfires are a necessary part of the life cycle in the taiga; some, e.g. jack pine have cones which only open to release their seed after a fire, dispersing their seeds onto the newly cleared ground; certain species of fungi (such as morels ) are also known to do this. Grasses grow wherever they can find

5104-493: The harsh winters in their native ranges. Some larger mammals, such as bears , eat heartily during the summer in order to gain weight, and then go into hibernation during the winter. Other animals have adapted layers of fur or feathers to insulate them from the cold. Predatory mammals of the taiga must be adapted to travel long distances in search of scattered prey, or be able to supplement their diet with vegetation or other forms of food (such as raccoons ). Mammalian predators of

5192-700: The highest mountain of the Coast Mountains, lies in the Waddington Range of the Pacific Ranges. Just north of the Pacific Ranges lies the central subdivision known as the Kitimat Ranges. This subdivision extends from the Bella Coola River and Burke Channel in the south to the Nass River in the north. The third and northernmost subdivision of the Coast Mountains is the Boundary Ranges , extending from

5280-486: The interior of the continents, with the driest climates, the boreal forests might grade into temperate grassland . There are two major types of taiga. The southern part is the closed canopy forest , consisting of many closely-spaced trees and mossy groundcover. In clearings in the forest, shrubs and wildflowers are common, such as the fireweed and lupine . The other type is the lichen woodland or sparse taiga , with trees that are farther-spaced and lichen groundcover;

5368-425: The latter is common in the northernmost taiga. In the northernmost taiga, the forest cover is not only more sparse, but often stunted in growth form; moreover, ice-pruned , asymmetric black spruce (in North America) are often seen, with diminished foliage on the windward side. In Canada, Scandinavia and Finland, the boreal forest is usually divided into three subzones: The high boreal (northern boreal/taiga zone),

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5456-409: The length of the arc about 60 million years ago during the Albian and Aptian faunal stages of the Cretaceous period. This resulted from the changing geometry of the Kula Plate, which progressively developed a more northerly movement along the Pacific Northwest . Instead of subducting beneath the Pacific Northwest, the Kula Plate began subducting underneath southwestern Yukon and Alaska and during

5544-423: The long, cold winter is the dominant feature. This climate is classified as Dfc , Dwc , Dsc , Dfd and Dwd in the Köppen climate classification scheme, meaning that the short summers (24 h average 10 °C (50 °F) or more), although generally warm and humid, only last 1–3 months, while winters, with average temperatures below freezing, last 5–7 months. In Siberian taiga the average temperature of

5632-417: The lower stretches of the Fraser River to Bella Coola . Included in this subdivision is four of the five major coastal icecaps in the southern Coast Mountains. These are the largest temperate-latitude icecaps in the world and fuel a number of major rivers . Other than logging and a large ski resort at the resort town of Whistler , most of the land in the range is completely undeveloped. Mount Waddington ,

5720-406: The mean annual temperature reaches down to −10 °C (14 °F), and the lowest reliably recorded temperatures in the Northern Hemisphere were recorded in the taiga of northeastern Russia. Taiga has a subarctic climate with very large temperature range between seasons. −20 °C (−4 °F) would be a typical winter day temperature and 18 °C (64 °F) an average summer day, but

5808-427: The most explosive young volcanoes in Canada. Further north the northwesterly structural trend of the Coast Mountains lies partly in a large continental rift responsible for the creation of several volcanoes. These volcanoes form part of the Northern Cordilleran Volcanic Province , the most volcanically active area in Canada. The first event began 130 million years ago when a group of active volcanic islands approached

5896-403: The most extreme winter weather. The Dahurian larch tolerates the coldest winters of the Northern Hemisphere, in eastern Siberia. The very southernmost parts of the taiga may have trees such as oak , maple , elm and lime scattered among the conifers, and there is usually a gradual transition into a temperate, mixed forest, such as the eastern forest-boreal transition of eastern Canada. In

5984-449: The northern motion of the Kula Plate might have been between 140 mm (6 in) and 110 mm (4 in) per year. However, other geologic studies determined the Kula Plate moved at a rate as fast as 200 mm (8 in) per year. Download coordinates as: Taiga Taiga or tayga ( / ˈ t aɪ ɡ ə / TY -gə ; Russian : тайга́ , IPA: [tɐjˈɡa] ), also known as boreal forest or snow forest ,

6072-507: The origin of this differential use in North America and how this differentiation distorts established Russian usage. Climate change is a threat to taiga, and how the carbon dioxide absorbed or emitted should be treated by carbon accounting is controversial. Taiga covers 17 million square kilometres (6.6 million square miles) or 11.5% of the Earth's land area, second only to deserts and xeric shrublands . The largest areas are located in Russia and Canada. In Sweden taiga

6160-406: The patterns of vegetation on the landscape, which in the east favour black spruce, paper birch, and jack pine over balsam fir, and in the west give the advantage to aspen, jack pine, black spruce, and birch over white spruce. Many investigators have reported the ubiquity of charcoal under the forest floor and in the upper soil profile. Charcoal in soils provided Bryson et al. (1965) with clues about

6248-471: The pines to disperse seed at all seasons. Only balsam fir and alpine fir seem to be poorly adapted to reproduce after fire, as their cones disintegrate at maturity, leaving no seed in the crowns. The oldest forests in the northwest boreal region, some older than 300 years, are of white spruce occurring as pure stands on moist floodplains . Here, the frequency of fire is much less than on adjacent uplands dominated by pine, black spruce and aspen. In contrast, in

6336-423: The presently existing taiga forests into one of the two woodland states or even into a treeless steppe - but it could also shift tundra areas into woodland or forest states as they warm and become more suitable for tree growth. In keeping with this hypothesis, several studies published in the early 2010s found that there was already a substantial drought-induced tree loss in the western Canadian boreal forests since

6424-782: The region; and the Eastern Siberian taiga is a vast larch forest. Taiga in its current form is a relatively recent phenomenon, having only existed for the last 12,000 years since the beginning of the Holocene epoch, covering land that had been mammoth steppe or under the Scandinavian Ice Sheet in Eurasia and under the Laurentide Ice Sheet in North America during the Late Pleistocene . Although at high elevations taiga grades into alpine tundra through Krummholz , it

6512-416: The soil. Acids from evergreen needles further leach the soil, creating spodosol , also known as podzol , and the acidic forest floor often has only lichens and some mosses growing on it. In clearings in the forest and in areas with more boreal deciduous trees, there are more herbs and berries growing, and soils are consequently deeper. Since North America and Eurasia were originally connected by

6600-434: The southern limit more variable. Depending on rainfall, and taiga may be replaced by forest steppe south of the 15 °C (59 °F) July isotherm where rainfall is very low, but more typically extends south to the 18 °C (64 °F) July isotherm, and locally where rainfall is higher, such as in eastern Siberia and adjacent Outer Manchuria , south to the 20 °C (68 °F) July isotherm. In these warmer areas

6688-542: The summer months. The cold winters and short summers make the taiga a challenging biome for reptiles and amphibians , which depend on environmental conditions to regulate their body temperatures. There are only a few species in the boreal forest, including red-sided garter snake , common European adder , blue-spotted salamander , northern two-lined salamander , Siberian salamander , wood frog , northern leopard frog , boreal chorus frog , American toad , and Canadian toad . Most hibernate underground in winter. Fish of

6776-512: The sun is low in the horizon for most of the year, it is difficult for plants to generate energy from photosynthesis . Pine, spruce and fir do not lose their leaves seasonally and are able to photosynthesize with their older leaves in late winter and spring when light is good but temperatures are still too low for new growth to commence. The adaptation of evergreen needles limits the water lost due to transpiration and their dark green color increases their absorption of sunlight. Although precipitation

6864-514: The taiga has higher species diversity, with more warmth-loving species such as Korean pine , Jezo spruce , and Manchurian fir , and merges gradually into mixed temperate forest or, more locally (on the Pacific Ocean coasts of North America and Asia), into coniferous temperate rainforests where oak and hornbeam appear and join the conifers, birch and Populus tremula . The area currently classified as taiga in Europe and North America (except Alaska)

6952-531: The taiga include Canada lynx , Eurasian lynx , stoat , Siberian weasel , least weasel , sable , American marten , North American river otter , European otter , American mink , wolverine , Asian badger , fisher , timber wolf , Mongolian wolf , coyote , red fox , Arctic fox , grizzly bear , American black bear , Asiatic black bear , Ussuri brown bear , polar bear (only small areas of northern taiga), Siberian tiger , and Amur leopard . More than 300 species of birds have their nesting grounds in

7040-401: The taiga must be able to withstand cold water conditions and be able to adapt to life under ice-covered water. Species in the taiga include Alaska blackfish , northern pike , walleye , longnose sucker , white sucker , various species of cisco , lake whitefish , round whitefish , pygmy whitefish , Arctic lamprey , various grayling species, brook trout (including sea-run brook trout in

7128-787: The taiga. In Canada and Scandinavia, the growing season is often estimated by using the period of the year when the 24-hour average temperature is +5 °C (41 °F) or more. For the Taiga Plains in Canada, growing season varies from 80 to 150 days, and in the Taiga Shield from 100 to 140 days. Other sources define growing season by frost-free days. Data for locations in southwest Yukon gives 80–120 frost-free days. The closed canopy boreal forest in Kenozersky National Park near Plesetsk , Arkhangelsk Province , Russia, on average has 108 frost-free days. The longest growing season

7216-408: The taiga. Siberian thrush , white-throated sparrow , and black-throated green warbler migrate to this habitat to take advantage of the long summer days and abundance of insects found around the numerous bogs and lakes. Of the 300 species of birds that summer in the taiga, only 30 stay for the winter. These are either carrion -feeding or large raptors that can take live mammal prey, such as

7304-467: The tree line in the subarctic spruce-lichen woodlands. The longest cycles, possibly 300 years, probably occur in the western boreal in floodplain white spruce. Amiro et al. (2001) calculated the mean fire cycle for the period 1980 to 1999 in the Canadian boreal forest (including taiga) at 126 years. Increased fire activity has been predicted for western Canada, but parts of eastern Canada may experience less fire in future because of greater precipitation in

7392-404: The warmest month of the year usually is 10 °C (50 °F) or less. High latitudes mean that the sun does not rise far above the horizon, and less solar energy is received than further south. But the high latitude also ensures very long summer days, as the sun stays above the horizon nearly 20 hours each day, or up to 24 hours, with only around 6 hours of daylight, or none, occurring in

7480-513: The world. On its eastern flanks, the range tapers to the dry Interior Plateau and the subarctic boreal forests of the Skeena Mountains and Stikine Plateau . The Coast Mountains are part of the Pacific Ring of Fire —the ring of volcanoes and associated mountains around the Pacific Ocean —and contain some of British Columbia's highest mountains. Mount Waddington is the highest mountain of

7568-431: The zone of Cretaceous dextral thrust faulting appears to have been widespread. It was also during this period when massive amounts of molten granite intruded highly deformed ocean rocks and assorted fragments from pre-existing island arcs, largely remnants of the Bridge River Ocean. This molten granite burned the old oceanic sediments into a glittering medium-grade metamorphic rock called schist . The older intrusions of

7656-407: Was recently glaciated . As the glaciers receded they left depressions in the topography that have since filled with water, creating lakes and bogs (especially muskeg soil) found throughout the taiga. Taiga soil tends to be young and poor in nutrients, lacking the deep, organically enriched profile present in temperate deciduous forests. The colder climate hinders development of soil, and

7744-525: Was completed, Coast Range Arc volcanism returned and sections of the arc were uplifted considerably in latest Cretaceous time. This started a period of mountain building that affected much of western North America called the Laramide orogeny . In particular a large area of dextral transpression and southwest-directed thrust faulting was active from 75 to 66 million years ago. Much of the record of this deformation has been overridden by Tertiary age structures and

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