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74-599: The ACh-30 was a development of the experimental AN-1RTK turbo-supercharged diesel engine that had begun development in the early 1930s. It was initially designated as the AD-5 when development began in the sharashka attached to Factory ( Zavod ) No. 82 at Tushino Airport in 1939. Construction of the first five prototypes began at the end of that year and it passed its tests in early 1940. Preparations to begin series manufacture at Factory No. 82 began in May 1940, but actual production

148-751: A Red Army microbiology facility on Gorodomlya Island on Lake Seliger . In 1938, Lavrenty Beria , a senior NKVD official, created the Department of Special Design Bureaus at the NKVD USSR (Отдел особых конструкторских бюро НКВД СССР). In 1939, the unit was renamed the Special Technical Bureau at the NKVD USSR (Особое техническое бюро НКВД СССР) and placed under the control of General Valentin Kravchenko  [ ru ] , under Beria's immediate supervision. In 1941 it received

222-473: A bit earlier than that. Factory No. 45 began production in the fourth quarter of 1943. Some 1450 ACh-30Bs were built before production ended at both factories in September 1945. The ACh-30B was tested as a motorjet in which the jet engine's compressor was driven by an incorporated piston engine (as opposed to being driven by a turbine extracting power from the jet's exhaust as in a normal turbojet ). It

296-412: 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

370-454: 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

444-484: 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,

518-560: 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

592-506: A poorly-organized, impromptu, or bluffing organization, which in its turn comes from the criminal argot term sharaga (шарага) for a band of thieves, hoodlums, etc. ) The scientists and engineers at a sharashka were prisoners picked by the Soviet government from various camps and prisons and assigned to work on scientific and technological problems. Living conditions were usually much better than in an average taiga camp, mostly because of

666-408: 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

740-409: A secret name, the 4th Special Department of the NKVD USSR (4-й спецотдел НКВД СССР). In 1949, the scope of the sharashkas significantly increased. Previously the work done there was of military and defense character. The MVD Order No. 001020 dated November 9, 1949 decreed installation of "Special technical and design bureaus" for a wide variety of civilian research and development , particularly in

814-412: 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

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888-857: 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 is not exclusively an alpine biome, and unlike subalpine forest , much of taiga

962-581: 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 is associated with the Norrland terrain . After

1036-409: 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

1110-427: 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

1184-554: 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,

1258-588: 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 the origin of this differential use in North America and how this differentiation distorts established Russian usage. Climate change

1332-416: 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

1406-624: 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 the Scottish Highlands , some lowland/coastal areas of Iceland , and areas of northern Kazakhstan , northern Mongolia , and northern Japan (on

1480-547: 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

1554-485: 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

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1628-699: 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

1702-498: 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 the coldest month is between −6 °C (21 °F) and −50 °C (−58 °F). There are also some much smaller areas grading towards

1776-788: The Mikulin AM-38 and the Klimov M-105 engines with intercoolers . That from the AM-38 was more successful and was put into production as the M-30B. Thirty-five incomplete M-30 engines were modified beginning in August into M-30Bs and then thirty-four M-30Bs were produced during the rest of 1942. Oddly the ACh-30B, as the engine was now known, was not formally accepted for series production until 19 June 1943, although production had begun quite

1850-680: 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

1924-562: The Supreme Soviet of the National Economy and OGPU issued a secret circulaire "Об использовании на производстве специалистов, осужденных за вредительство" ("On the use in production of specialists convicted of wrecking "). It ordered the use of "engineers-wreckers" to "eliminate the consequences of wrecking" and to provide them with the necessary literature, materials and devices for this. It also said that "the use of

1998-419: 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

2072-517: 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 the long, cold winter is the dominant feature. This climate is classified as Dfc , Dwc , Dsc , Dfd and Dwd in

2146-445: 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

2220-498: 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

2294-451: The "remote areas of the Union ". The 4th Special Department was disbanded in 1953. Taiga Taiga or tayga ( / ˈ t aɪ ɡ ə / TY -gə ; Russian : тайга́ , IPA: [tɐjˈɡa] ), also known as boreal forest or snow forest , is a biome characterized by coniferous forests consisting mostly of pines , spruces , and larches . The taiga or boreal forest

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2368-563: The 1950s within the Soviet Gulag labor camp system, as well as in other facilities under the supervision of the Soviet secret service . Formally various secret R&D facilities were called "special design bureau" Russian : особое конструкторское бюро, ОКБ and similar terms. Etymologically, the word sharashka derives from a Russian slang expression sharashkina kontora , ("Sharashka's office"), an ironic, derogatory term to denote

2442-466: 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

2516-590: 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

2590-441: 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

2664-457: The absence of hard labor. The results of the research in sharashkas were usually published (if published at all) under the names of prominent Soviet scientists without credit given to the real researchers, whose names frequently have been forgotten. Some of the scientists and engineers imprisoned in sharashkas were released during and after World War II (1939–1945) to continue independent careers; some became world-renowned. On May 15, 1930,

2738-440: 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

2812-471: 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

2886-527: 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

2960-526: 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

3034-487: 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

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3108-539: 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

3182-459: 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

3256-466: The following year created a special prison laboratory (known as the Bureau of Special Purpose or BON ) where around nineteen leading plague and tularaemia specialists were forced to work on the development of biological weapons. Colonel Mikhail Mikhailovich Faibich, a specialist in typhus , was the first director of BON . The laboratory was in operation until 1936, when the scientists were transferred to

3330-459: 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

3404-404: 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

3478-519: 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

3552-493: 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

3626-486: 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;

3700-503: 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 the region; and the Eastern Siberian taiga is a vast larch forest. Taiga in its current form

3774-425: 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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3848-474: 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

3922-491: 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 is found in areas with mean annual temperature below freezing, whilst in

3996-530: The oil pumps. Production was cancelled when Factory No. 82 was forced to evacuate in the fall of 1941 because of the German advance on Moscow. Production was reinitiated in the evacuated workshops of Factory No. 82 by Factory No. 500 in June 1942, thirty-two engines being completed during the year. Development of supercharged versions began about the same time, using geared, centrifugal-type superchargers adapted from

4070-406: 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

4144-446: 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 the mean annual temperature reaches down to −10 °C (14 °F), and

4218-471: 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

4292-423: 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

4366-416: 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

4440-434: 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

4514-542: 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

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4588-512: 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

4662-518: 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)

4736-531: 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

4810-401: 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

4884-809: 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

4958-408: 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

5032-467: 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

5106-404: 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

5180-787: The wreckers must be organized in such a way that their work was carried out on the premises of the organs of OGPU." In 1930 Leonid Ramzin and other engineers sentenced in the Industrial Party Trial were formed into a special design bureau under the Joint State Political Directorate (OGPU), which was then the Soviet secret police . In July 1931, the OGPU seized control of the Intercession Convent  [ ru ] in Suzdal and

5254-407: 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

5328-659: Was bench tested from June 1944 through May 1945, but was never installed in any aircraft. The jet engine's thrust was 1,925 lbf (8.56 kN) and the equivalent horsepower of the combination was 4,500 hp (3,400 kW). The combination weighed 1,700 kg (3,700 lb). Versions of the ACh-30 were evaluated on the Ilyushin Il-6 and the ANT-67, a long-range version of the Tupolev Tu-2 , but neither aircraft

5402-554: Was delayed until 1941 when forty-four were built as the M-30. Production was planned to be transferred to the Kharkov Tractor Factory , but this was cancelled before any engines were built. The M-30 had proven to be unsatisfactory in service, as it was unreliable and troublesome at high altitudes and in cold conditions. Specific problems were its failure to deliver full rpm and it suffered from oil blowouts and failures of

5476-611: Was put into production. It was also proposed for use on the Tupolev Tu-8 S and the MN executive transport, but neither of those projects progressed past design proposal stage. Data from Kotelnikov, Russian Piston Aero Engines Related development Comparable engines Related lists Sharashka Sharashkas (singular: Russian : шара́шка , [ʂɐˈraʂkə] ; sometimes sharaga , sharazhka ) were secret research and development laboratories operating from 1930 to

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