The growth and management of Douglas fir in the Pacific Northwest (1911) (14579043950)

Identifier: growthmanagement17mung (find matches)
Title: The growth and management of Douglas fir in the Pacific Northwest
Year: 1911 (1910s)
Authors: Munger, Thornton T. (Thornton Taft), 1883- United States. Forest Service
Subjects: Douglas fir Northwest, Pacific Douglas fir Northwest, Pacific Growth Forest management Northwest, Pacific
Publisher: Washington, Govt. Print. Off.
Contributing Library: U.S. Department of Agriculture, National Agricultural Library
Digitizing Sponsor: U.S. Department of Agriculture, National Agricultural Library



Text Appearing Before Image:
orms of the tree which are known by local names. The terms red fir and yellow fir are oftenused to distinguish between two fairly distinct forms of wood which this single species produces, dependingupon the age of the tree and the conditions under which it has grown. The tenn red fir is applied totrees which are ordinarily immature and have rather coarse-grained and reddish-colored wood; the term yellow fir applies to trees which are of mature age and whose wood is fine grained, yellow in color, rathersoft, and easily worked. GROWTH AND MANAGEMENT OF DOUGLAS FIR. 7 DENSITY OF STAND. The ability of a tree to endure shade, or in other words, its demandfor light, decides how many trees will grow on an acre, and is there-fore an important characteristic of a tree. Douglas fir is moderatelydependent upon light, being able to endure more shade than someof its associates, but less than others, such as western hemlock andwestern red cedar. In order to remain alive after their first few years,
Text Appearing After Image:
Fig. 1.—Part of a 45-jear-old stand of Douglas fir uear Crow, Oreg., which is occupying landformerly covered with nothing but brush, because of repeated fires set by Indians. Douglas firs must receive direct top light, and with advancing agethey become more exacting in tliis regard; trees which are overshad-owed completely by their neighbors quickly die. This fact explainswhy this tree, in order to attain optimum development, should grow ineven-aged stands, where all the trees are of about the same heightand all receive du^ect top light. (Fig. 1.) GEOWTH AND MANAGEMENT OF DOUGLAS FIR. Douglas iir has to an unusual degree the ability to form densestands, and tliis in part accounts for its immense yields per acre.Table 1 gives the number of trees of various sizes that are normallyfound in even-aged forests of several ages. At 20 years of age thereare 990 trees to the acre, at 30 years, 580, and so on, decreasingly,until at 100 years there are about 115 td the acre. After this thenumbe