There are a number of wood properties which affect the quality of forest products such as lumber and pulp. Of these, wood density is considered by some to be the single most important physical characteristic because it is an excellent predictor of strength, stiffness, hardness, and paper-making capacities. Accurately assessing...
• A technique for measuring in vitro respiration was investigated to understand why rates were higher than those reported in vivo and to elucidate trends within mature Pseudotsuga menziesii (Douglas‐fir) trees.
• Extracted increment cores were divided into 3–4 radial depths and a gas chromatograph was used to compare respiration...
The two-parameter Weibull function was used to predict forest stand diameter distributions and growth. Diameter distribution models were developed for even-aged Douglas-fir stands, 20 to 40 years old, in Oregon and Washington. In order to test if the two-parameter Weibull function can adequately describe the diameter distributions of such stands,...
Chapter 1 Growth and Survival of Root-Wrenched Douglas-fir Seedlings Root wrenching of seedlings (severing the roots 15 cm below the soil surface) was investigated as a nursery practice to improve growth and survival of field-planted Douglas-fir from six local seed sources
in the Pacific Northwest. At lifting, shoots of wrenched...
The effect of lifting date and root-pruning treatments on
water potential, root regeneration, and shoot growth of six-month-old
and three-year-old Douglas-fir seedlings bare-root transplanted
into a growth chamber, and sawdust bed, respectively, was studied.
Root growth in six-month-old and three-year-old seedlings was
highest in February and August respectively. Survival was...
Douglas-fir and western hemlock growth and stocking were examined on two neighboring clear-cut watersheds in the Western Cascades of Oregon and related to the intensity of burning and logging disturbance, habitat type, soil type, aspect and the influence of percent cover of both invading Ceanothus species and residual Acer circinatum....
From a preliminary 1969 foliar analysis, eight provenances were chosen from the sixteen included in a region-wide, reciprocal Doulgas-fir provenance study for further study of variation in foliar nutrition. In the fall of 1969 separate foliar samples were collected from ten
trees per provenance at each of ten plantations ranging...
Understory conifer regeneration needs to occur beneath conifer-dominated
canopies if two-storied or uneven-aged structures are to be considered for western
Oregon Coast Range stand management. To ensure adequate numbers of seedlings
to meet stocking or habitat structure objectives, planting may be a solution. We
undertook a multi-level study to determine...
Because Douglas-fir [Pseudotsuga menziesii(Mirb.)Franco] bark is a raw material produced in our renewable forests along with wood, an understanding of the ultrastructure of bark cells is of paramount importance if wood technologists are to utilize the bark to the fullest potential. The objectives of this study were to develop microscopic...
The seeds of Douglas fir, a representative of the gymnosperm
flora, were studied at six stages of germination to discern the structures
of food reserves and to study ultrastructural changes occurring
during germination in the embryo and resulting seedlings.
The materials were fixed in three fixatives, dehydrated with
ethanol series,...
Bigleaf maple (Acer iaacrophyllunt) is a deciduous, persistent, sprouting species that frequently accounts for as much as 20% of the basal area in Douglas-fir forests. Because of the lack of knowledge of the role of bigleaf maple in Douglas-fir forest ecosystems and the problems that it poses as a vigorous...
In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
Creep in wood has been observed since 1833 but only recently
has it been studied quantitatively. The aim of this paper is to study
the time-dependent deflections of Douglas fir, Coast Region beams
in bending and shear modes. The general method of approach used is
that of large scale observation....
Existing forest site maps have been described as "invaluable
tools" in forest management. Their, economic value potentially materializes
as the summed advantage from better decisions in all phases of
forestry.
Via Bayesian decision analysis, this study establishes optimal
use and economic value of site information for one facet of management...