In 1957 three Douglas-fir stands (15-, 25-, and 40-year-old age classes) were selected on a tree farm in the Cascade foothills of
northwestern Oregon to study factors affecting site productivity. Soil-moisture, soil-temperature and seasonal radial- growth pattern measurements were made with a Colman moisture meter and a dial gauge dendrometer...
In the preparation of this thesis, the writer does not claim to have discovered any great truths or their underlying causes. As the title indicates, the work is a summary of some of the more important investigational activities on the McDonald Forest. This line of endeavor was chosen because it...
The purpose of this thesis is to outline the principles involved in the reconnaissance, survey, and design of forest roads in the Douglas-fir Region. The reconnaissance survey is the most important element in road location. Poor reconnaissance often results in abandonment of the route at considerable expense. The ground slope...
Moisture content and shrinkage were determined on specimens equilibrated at two conditions for equilibrium moisture content (EMC) at room temperature after the specimens had been dried under a variety of constant temperatures with constant EMC's. Moisture content at room temperature equilibrium was less for specimens dried at high temperature than...
To test the effects of kiln-drying on strength properties of Douglas fir and western hemlock, temperatures to 230 F, conditions for equilibrium moisture contents of 6 percent and 12 percent, and prolonged heating were investigated.
Prolonged heating and choice of conditions for 6 percent or 12 percent equilibrium moisture content...
Checking was influenced b drying conditions. This influence was greatest before average moisture content reached 20 per cent, but tension in surface layers caused checking even below this point.
Neither high initial dry-bulb temperature nor initial conditions of high equilibrium moisture content were conducive to checking.
High temperature and high...
Four charges of S-inch paper roll plugs of Oregon maple were kiln-dried at various temperatures and humidities. The charge with the most desirable combination of short drying time and low degrade was dried to 12 per cent moisture content in lit hours, using a dry-bulb temperature of 160 degrees F...
The Oregon Forest Products Laboratory was asked in July 1953 by the Oregon Alder and Maple Company, Willamina, to work on the problem of dark stain which developed at sticker crossings in air-drying red alder (Alnus rubra, Bong.) during the summer months.
Previous experience at the Oregon Alder and Maple...
The vapor-drying process is described briefly and its present status in industry is discussed. Fairly extensive data on the vapor drying of 1-, 2-, and 4-inch Douglas-fir and 2-inch western hemlock lumber are presented. Exploratory work on the vapor drying of redwood, Pacific madrone, red alder and ponderosa pine is...
The increasing volume of young-growth Douglas-fir timber cut in the Pacific Northwest emphasizes the need for more knowledge on the characteristics of lumber sawed from these trees.
The study described here was initiated to learn the extent arid causes of degrade resulting from kiln-drying young-growth Douglas-fir dimension lumber. At the...
Spectroradiometric analyses were made to examine the light filtering capacity of coniferous forests and to establish the lower light energy limits for growth of Pseudotsuga menziesii (Mirb. ) Franco, Abies concolor (Gord. and Glend.) Lindi. and Pinus ponderosa Dougi. Visible energy(400-750 nm) was recorded at 48 points under four mixed...