can prosper; in ideal conditions, young trees may grow per year. It is naturalized in some parts of Ireland and Great Britain, where it was introduced in 1831 by David Douglas, 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 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. But in Norway, the Sitka spruce is now considered an invasive species, and effort to get rid of it is being made. The resonant wood 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 sailboat spars, and aircraft wing spars (including flying models). 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 flavor spruce beer and are boiled to make syrup. Culture 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. Chemistry The stilbene glucosides astringin, isorhapontin, and piceid can be found in the bark of the Sitka spruce. Burls 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." See also List of tallest trees References External links 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