Great Trees of the American Forest
Douglas-Fir, ponderosa and southern pines, yellow-poplar, sugar maple, and the white oak are great American trees, beauties on the landscape wherever they stand. As forest trees, they are grown to serve many useful purposes. You can derive more enjoyment from your travels through the National Forests by observing these and other species and learning why each grows best in its particular environment.
Douglas-Fir, the State tree of Oregon, produces more wood products than any other American tree and perhaps is the world’s most valuable species of conifer. It grows in moist forests from the Rocky Mountains to the Pacific coast, reaching its largest size on the western slopes of the Cascade Mountains and along the northwest coast, where soil is rich and moisture plentiful. Douglas-fir grows second in size only to the California sequoias, giant sequoia and redwood (Sequoia gigantea and Sequoia sempervirens), with heights of 200 feet or more and diameters of 3 to 6 feet. Under favorable conditions individual trees may live a thousand years, grow 10 feet through and 300 feet tall, with furrowed, cinnamon-brown bark 1 foot thick.
Douglas-fir scatters its seed prolifically (with an average of 42,000 seeds per pound taken over its entire range; California has 30,000-35,000, British Columbia 49,000) and young trees grow fast and dense in the mineral soil of the Northwest. At 10 years they are 15 feet high, and in 25 years are twice as tall with sometimes as many as 1,000 trees to the acre. As they grow, the forest thins naturally; in a century the trees can reach 200 feet in height and may then number about 115 to the acre.
Small trees are hardy and attractive for ornamental planting. With their soft, rich green needles hanging on long after cutting, they are also beautiful and popular Christmas trees.
The wood, yellowish to light red in color, is strong for its fairly light weight, and is resistant to decay. The size of the tree permits the manufacture of lumber remarkably free of knots and other defects, with pieces 60 feet long by 2 feet square. The softwood veneer and plywood industries depend almost entirely on Douglas-fir for raw materials. Recently new uses (fiberboard, book paper, wrapping paper) have been developed for sawmill leftovers.
For years this unique conifer was a botanical puzzler, having been called spruce, hemlock, balsam fir, and even pine. The scientific name meaning false hemlock (Pseudotsuga menziesii) honors Dr. Archibald Menzies, physician and naturalist with Captain Vancouver’s voyage, who discovered this tree on the Pacific coast in 1791. It remained for the roving Scotch botanical collector David Douglas to send the first seeds to Europe in 1827. Soft, deep yellow-green or blue-green needles about an inch long, flattened and pointed, grow all around the twig. The oval cone with distinctive three-pronged bracts hangs like a pendant.
Ponderosa Pine, a beautiful and hardy tree, grows in every State west of the Great Plains, and is the State tree of Montana. It has a total stand greater than any native tree species except Douglas-fir, and reaches maximum growth in the resin-scented Sierra forests of California: over 200 feet in height, 5 to 8 feet in diameter, 500 years in age.