Sitka spruce

Appearance

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 not have branches lower than 30–40 m. The shoots are very pale buff-brown, almost white, and glabrous 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 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.

Distribution

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. 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.

Uses

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 and New Zealand, though not so extensively as to be considered invasive. Sitka spruce is also planted extensively in Denmark, Norway and Iceland. 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.

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. 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.

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.

Cultural

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 Native American people. It was illegally felled in 1997 by Grant Hadwin, although saplings grown from cuttings can now be found near its original site.