DESCRIPTION OF SPECIES.
DOUGLAS FIR (PSEUDOTSUGA TAXIFOLIA)
The Douglas fir (figs. 2, 3, 4, and 5) is the best known and the most important timber tree of western North America. It is found from British Columbia southward to northern Mexico. The finest forests occur in Oregon and Washington at low elevations. The Douglas fir is common in the park up to 3,500 feet, sometimes in nearly pure stands, but more often mixed with other species. It grows in all situations. In the higher mountains it prefers warm southern exposures and is seldom found on wind-swept ridges. It seeds annually, but most profusely at intervals three or four yars apart. The red squirrels gather and store large quantities of the cones in order to provide a supply of the seeds for their winter rations. The growth of the young tree is very rapid. As the tree becomes older the rate of growth varies with situation and the character of the soil so that the size does not closely determine the age of the tree.
The Douglas fir is a long-lived tree, and specimens are occasionally found 250 to 270 feet high and over 8 feet in diameter and between 600 and 700 years in age. It reaches its greatest height and most perfect proportions in mature even-age stands growing on fairly moist well-drained bench lands. Under these conditions it is a very tall and beautiful tree. The trunk is straight, round, and free from branches for two-thirds of its height and tapers gently to the crown. The dark-brown deep-furrowed bark is 5 to 10 inches thick at the base of the tree.
The Douglas fir ranks first among the trees of the Pacific slope in importance for the production of lumber. It is often sold under the name of Oregon pine. Lumber dealers class the coarse-grained reddish wood produced by the young growth in open forests as "red fir." The older growth produced when the foreest is more dense is a finer grained and more valuable wood, sold under the name of "yellow fir."
The Douglas fir is used for nearly all purposes when durability, strength, and hardness are desirable. It is made into dimension timbers, lumber, flooring, and is particularly adapted for masts and spars. The lumber is shipped by rail to the Middle Western States. The foreign cargo shipments are made to all parts of the world. The greatest amount goes to Australia, the west coasts of South America, China, the United Kingdom, and Europe, Japan, and the South Sea Islands. Coastwise shipments are made to California, Alaska, and Panama. Large quantities of the seed of this tree are sent to Europe, where the Douglas fir is grown for timber and for ornament.
Last Updated: 02-Feb-2007