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By far the best-known is the very widespread and abundant North American species Pseudotsuga menziesii, a taxonomically complex species [14] divided into two major varieties (treated as distinct species or subspecies by some botanists): coast Douglas-fir or "green Douglas-fir", on the Pacific coast; and Rocky Mountain Douglas-fir or "interior ...
As a hem fir, the trunk of the grand fir is considered slightly below the "Douglas fir-larch" species combination in strength, and stronger than the "Douglas fir-South" and "spruce-pine-fir (South)" species combos (both umbrella terms for a number of species with similar wood).
Douglas-fir is one of the world's best timber-producing species and yields more timber than any other species in North America, making the forestlands of western Oregon, Washington, and British Columbia the most productive on the continent. In 2011, Douglas-fir represented 34.2% of US lumber exports, to a total of 1.053 billion board-feet.
The Janka hardness test (English: / ˈ dʒ æ ŋ k ə /; [1] German:), created by Austrian-born American researcher Gabriel Janka (1864–1932), measures the resistance of a sample of wood to denting and wear.
The bark is brown, thin, and furrowed (outwardly appearing similar to that of Douglas-fir). [6] The crown is a very neat broad conic shape in young trees with a strongly drooping lead shoot, becoming cylindrical in older trees, which may have no branches in the lowest 30–40 m (100–130 ft).
Coast Douglas-fir is the second-tallest conifer in the world (after coast redwood), and the third-tallest of all trees, (after Eucalyptus regnans).Currently, coast Douglas-fir trees 60–75 metres (197–246 ft) or more in height and 1.5–2 metres (4.9–6.6 ft) in diameter are common in old growth stands, [4] and maximum heights of 100–120 metres (330–390 ft) and diameters up to 4.5–5. ...
Timber is classified by tree species (e.g., southern pine, douglas fir, etc.) and its strength is graded using numerous coefficients that correspond to the number of knots, the moisture content, the temperature, the grain direction, the number of holes, and other factors.
Pseudotsuga menziesii var. lindleyana, commonly known as the Mexican Douglas-fir, is a conifer in the genus Pseudotsuga that is endemic to Mexico. [1] DNA sequence [2] and morphological [3] evidence suggests it is most closely related to Rocky Mountain Douglas-fir (P. menziesii var. glauca) and might best be treated as an additional variety within P. menziesii.