| Picea sitchensis Sitka Spruce |
|
|---|---|
| Quinault Lake Spruce, Largest according to American Forest by points | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Pinaceae |
| Genus: | Picea |
| Species: | P. sitchensis |
| Binomial name | |
| Picea sitchensis (Bong.) Carr. |
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| Range | |
Picea sitchensis, the Sitka Spruce, is a large coniferous evergreen tree growing up to 80 m tall,[1] and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter . It is by far the largest species of spruce; the fifth largest conifer in the world (behind Giant Sequoia, Coast Redwood, Kauri and Western Red Cedar);[2] and the third tallest conifer species (after Coast Redwood and Coast Douglas-fir). The Sitka Spruce is one of only five species documented to reach 300 feet in height.[3] It acquires its name from the community of Sitka, Alaska. The Carmanah Giant, towers 95 metres (315 ft) over the lush valley of Carmanah Creek, in Carmanah Walbran provincial Park. Its 9.4 meter diameter makes it Canada's largest Sitka Spruce.
Contents |
The bark is thin and scaly, flaking off in small circular plates 5–20 cm across. The crown is broad conic in young trees, becoming cylindric in older trees; old trees may have no branches in the lowest 30–40 m. 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 mm long, flattened in cross-section, 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, 6–10 cm long [4] and 2 cm broad when closed, opening to 3 cm broad. They have thin, flexible scales 15–20 mm 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, 3 mm long, with a slender, 7–9 mm long pale brown wing.
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 90 m tall may still be seen in the Pacific Rim National Park and Carmanah Walbran Provincial Park on Vancouver Island, British Columbia (the Carmanah Giant, at 96 m (315 ft) tall the tallest tree in Canada), and in the Olympic National Park, Washington and Prairie Creek Redwoods State Park, California (USA); two at the last site are just over 96 m (315 ft) tall. The Queets Spruce is the largest in the world with a trunk volume of 337 m3 (11,900 cu ft) it is 75.6 m (248 ft) tall and 455 cm (15 ft) in dbh. It is located near the Queets River in Olympic National Park, about 16 miles (26 km) from the Pacific Ocean.
Sitka Spruce is a long-lived tree, with individuals over 700 years old known. 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 (Van Pelt, 2001).
DNA analyses[5][6] has shown that only Picea breweriana has a more basal position than Sitka Spruce to the rest of the Spruce. The other thirty-three species of Spruce are more derived which suggests that Picea originated in North America.
Sitka Spruce is native to the west coast of North America, with its northwestern limit on Kodiak Island, Alaska, and its southeastern limit near Fort Bragg in northern California (Griffin & Critchfield 1972). It is closely associated with the temperate rain forests 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 nowhere does its range extend more than 80 km from the Pacific Ocean and its inlets.
Sitka Spruce is of major importance in forestry for timber and paper production. Outside of its native range, it is particularly valued for its fast growth on poor soils and exposed sites where few other trees can be grown successfully; in ideal conditions young trees may grow 1.5 m per year. It is naturalized in some parts of Ireland and Great Britain where it was introduced in 1831 (Mitchell, 1978) and New Zealand, though not so extensively as to be considered invasive. Sitka Spruce is also planted extensively in Denmark, Norway and Iceland.[7][8] In Norway, Sitka spruce was introduced in the early 1900s. An estimated 50,000 hectares 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.[9]
Sitka Spruce 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. For these reasons, the wood is also an important material for sailing boat spars, aircraft wing spars, and the nosecones of Trident missiles.[10] The Wright brothers' Flyer was built using Sitka Spruce, as were many or most aircraft before World War II; during that war, aircraft such as the British Mosquito used it as a substitute for strategically important aluminium.
Newly grown tips of Sitka Spruce branches are used to flavour spruce beer and are boiled to make syrup.
The root bark of Sitka Spruce trees is used in Native Alaskan basket-weaving designs.
A unique specimen with golden foliage that used to grow on Haida Gwaii, known as Kiidk'yaas, is sacred to the Haida Native American people. It was illegally felled, although saplings grown from cuttings can now be found near its original site.