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Picea sitchensis, the Sitka spruce, is a large, coniferous, evergreen tree growing to just over Template:Convert tall,<ref name="MonumentalTrees">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-largest conifer in the world (behind giant sequoia, coast redwood, kauri, and western red cedar),<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and the third-tallest conifer species (after coast redwood and South Tibetan cypress). The Sitka spruce is one of only five species documented to exceed Template:Cvt in height.<ref name="MonumentalTrees"/> Its name is derived from the community of Sitka in southeast Alaska, where it is prevalent. Its range hugs the western coast of Canada and the US and continues south into northern California.
DescriptionEdit
The bark is thin and scaly, flaking off in small, circular plates Template:Convert across. The inner bark is reddish-brown.<ref name="Arno-2020">Template:Cite book</ref> The crown is broad conic in young trees, becoming cylindric in older trees; old trees may not have branches lower than Template:Convert. The shoots are very pale buff-brown, almost white, and glabrous (hairless), but with prominent pulvini. The leaves are stiff, sharp, and needle-like, 15–25 millimeters long, flattened in cross-section,<ref name="Arno-2020" /> dark glaucous blue-green above with two or three thin lines of stomata, and blue-white below with two dense bands of stomata.
The cones are pendulous, slender cylindrical, Template:Convert long<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and Template:Convert broad when closed, opening to Template:Convert broad. They have thin, flexible scales Template:Convert long; the bracts just above the scales are the longest of any spruce, occasionally just exserted and visible on the closed cones. They are green or reddish, maturing pale brown 5–7 months after pollination. The seeds are black, Template:Convert long, with a slender, Template:Convert long pale brown wing.
SizeEdit
More than a century of logging has left only a remnant of the spruce forest. The largest trees were cut long before careful measurements could be made. Trees over Template:Convert tall may still be seen in Pacific Rim National Park and Carmanah Walbran Provincial Park on Vancouver Island, British Columbia (the Carmanah Giant, at Template:Convert tall, is the tallest tree in Canada),<ref>Template:Cite book</ref> and in Olympic National Park, Washington and Redwood National Park, California (United States), the latter of which houses the tallest individual measuring at 100.2 meters or 329 feet tall;<ref name="MonumentalTrees"/> two others at the last site are just over 96 m tall.<ref name=GD>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The Queets Spruce is the largest in the world with a trunk volume of Template:Convert, a height of Template:Convert, and a Template:Convert dbh.<ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It is located near the Queets River in Olympic National Park, about Template:Convert from the Pacific Ocean. Another specimen, from Klootchy Creek Park, Oregon, was previously recorded to be the largest with a circumference of Template:Convert and height of Template:Convert.
AgeEdit
Sitka spruce is a long-lived tree, with the oldest known individual just under 600 years old.<ref name=GD/> Because it grows rapidly under favorable conditions, large size may not indicate exceptional age. The Queets Spruce has been estimated to be only 350 to 450 years old, but adds more than a cubic meter of wood each year.<ref>Template:Cite book</ref>
Root systemEdit
Because it grows in extremely wet and poorly-drained soil, the Sitka spruce has a shallow root system with long lateral roots and few branchings. This also makes it susceptible to wind throw.<ref name=usfs>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
TaxonomyEdit
DNA analysis<ref name="Ran">Template:Cite journal</ref><ref name="Sigurgeirsson">Template:Cite journal</ref> has shown that only P. breweriana has a more basal position than Sitka spruce to the rest of the spruce. The other 33 species of spruce are more derived, which suggests that Picea originated in North America.<ref name=Ran/>
Distribution and habitatEdit
Sitka spruce is native to the west coast of North America, with its northwestern limit on Kenai Peninsula, Alaska, and its southeastern limit near Fort Bragg in northern California.<ref>Template:Cite book</ref> It is closely associated with the temperate rainforests and is found within a few kilometers of the coast in the southern portion of its range. North of Oregon, its range extends inland along river floodplains, but seldom does its range extend more than around Template:Convert from the Pacific Ocean and its inlets.<ref name="Arno-2020" /> It is situated at about Template:Convert above sea level in Alaska and generally below Template:Convert further south.<ref name="Arno-2020" />
Forests with the species average between Template:Convert of rain annually.<ref name="Arno-2020" /> It is tolerant to salty spray common in coastal dune habitat, such as at Cape Disappointment State Park in Washington, and prefers soils high in magnesium, calcium, and phosphorus.<ref name="usfs" />
Sitka spruce has been introduced to Europe as a lumber tree, and was first planted there in the 19th century. Sitka spruce plantations have become a dominant forest type in Great Britain and Ireland, making up 25% of forest cover in the former and 52% in the latter. Sitka spruce woodland is also present in France and Denmark, and the plant was introduced to Iceland and Norway in the early 20th century.<ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Observations of Sitka spruce along the Norwegian coast have shown the species to be growing 25–100% faster than the native Norway spruce there, even as far north as Vesterålen, and Sitka spruces planted along the southwest coast of Norway are growing fastest among the Sitka plantations in Europe.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
A 9-metre-tall, 100-year-old Sitka spruce growing in the middle of the permanently uninhabited sub-antarctic Campbell Island has been recognised by the Guinness World Records as the "most remote tree in the world".<ref>Template:Cite news</ref>
EcologyEdit
Value to wildlifeEdit
Sitka spruce provides critical habitat for a large variety of mammals, birds, reptiles, and amphibians. Its thick, sharp needles are poor browse for ungulates, and only the new spring growth is eaten. However, in Alaska and British Columbia the needles of Picea sitchensis comprise up to 90% of the winter diet of blue grouse.<ref name="usfs" />
Lichen-forming fungi Helocarpon lesdainii is found on Picea sitchensis trees in Harris Beach State Park, Oregon, USA.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
It provides cover and hiding places for a large variety of mammals, and good nesting and roosting habitat for birds. Sitka deer require old-growth Sitka spruce forests for winter habitat, as the extensive foliage holds a significant percentage of fallen snow in a given area, thus allowing for better understory browsing and easier migration for terrestrial animals. Cavity nesting birds favor Sitka spruce snags, and the tree is used by bald eagles,<ref name="Arno-2020" /> and peregrine falcons as nesting habitat.
Successional statusEdit
Sitka spruce is shade tolerant but not as much as its competitors,<ref name="Arno-2020" /> preferring full sun if possible. It is a pioneer on landslides, sand dunes, uplifted beaches, and deglaciated terrain. However, it is a climax species in coastal forests, where it can become dominant.<ref name="usfs" />
Fire ecologyEdit
Due to the prevalence of Sitka spruce in cool, wet climates, its thin bark and shallow root system are not adapted to resist fire damage and it is thus very susceptible. Sitka spruce forests have a fire regime of severe crown or surface fires on long intervals, (150 to 350+ years) which results in total stand replacement. Sitka spruce recolonizes burned sites via wind-dispersed seed from adjacent unburned forests.<ref name="usfs" />
UsesEdit
The root bark of Sitka spruce trees is used in Native Alaskan basket-weaving designs<ref name="uoregon">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and for rain hats. The pitch was used for caulking, chewing, and its medicinal properties.<ref name="usfs" /> Native Americans heated and plied the roots to make cord.<ref name="Arno-2020" /> The resin was used as glue and for waterproofing.<ref name="Arno-2020" /> Natives and pioneers split off shakes for construction use.<ref name="Arno-2020" /> The wood is light and relatively strong.<ref name="Arno-2020" />
Sitka spruce is of major importance in forestry for timber and paper production. Outside its native range, it is particularly valued for its fast growth on poor soils and exposed sites where few other trees can prosper; in ideal conditions, young trees may grow Template:Convert per year. It is naturalized in some parts of Ireland and Great Britain, where it was introduced in 1831 by David Douglas,<ref>Template:Cite book</ref> and New Zealand, though not so extensively as to be considered invasive. Sitka spruce is also planted extensively in Denmark, Norway, and Iceland.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> In Norway, Sitka spruce was introduced in the early 1900s. An estimated Template:Convert have been planted in Norway, mainly along the coast from Vest-Agder in the south to Troms in the north. It is more tolerant to wind and saline ocean air, and grows faster than the native Norway spruce.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> But in Norway, the Sitka spruce is now considered an invasive species, and effort to eliminate it is being made.<ref>Template:Cite news</ref><ref>Template:Cite news</ref>
The resonant wood<ref name="Arno-2020" /> is used widely in piano, harp, violin, and guitar manufacture, as its high strength-to-weight ratio and regular, knot-free rings make it an excellent conductor of sound.Template:Fact For these reasons, the wood is also an important material for sailboat spars, and aircraft wing spars (including flying models).Template:Fact The Wright brothers' Flyer was built using Sitka spruce, as were many aircraft before World War II; during that war, aircraft such as the British Mosquito used it as a substitute for strategically important aluminium.Template:Fact
Newly grown tips of Sitka spruce branches are used to flavor spruce beer and are boiled to make syrup.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Indigenous cultureEdit
A unique specimen with golden foliage that used to grow on Haida Gwaii, known as Kiidk'yaas or "The Golden Spruce", is sacred to the Haida First Nations people. It was illegally felled in 1997 by Grant Hadwin, although saplings grown from cuttings can now be found near its original site.
In the Lushootseed language, spoken in what is now Washington state, it is known as c̓əlaqayac.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
ChemistryEdit
The stilbene glucosides astringin, isorhapontin, and piceid can be found in the bark of the Sitka spruce.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
BurlsEdit
In the Olympic National Forest in Washington, Sitka spruce trees near the ocean sometimes develop burls.
According to a guidebook entitled Olympic Peninsula, "Damage to the tip or the bud of a Sitka spruce causes the growth cells to divide more rapidly than normal to form this swelling or burl. Even though the burls may look menacing, they do not affect the overall tree growth."<ref>Template:Cite book</ref>
See alsoEdit
ReferencesEdit
External linksEdit
- Picea sitchensis – information, genetic conservation units and related resources. European Forest Genetic Resources Programme (EUFORGEN)
- Gymnosperm Database
- Arboretum de Villardebelle – photos of cones of Picea sitchensis and related spruces
- Prof Stephen Sillett's webpage with photos taken during canopy research.
- Description of Sitka Spruce in forestry (PDF) by US Department of Agriculture
- Picea Sitchinesis 'Octopus tree'