Forests are important to Oregon for their beauty as well as economic value, and Douglas fir trees are among the most common and important in the state. Managing and monitoring Oregon’s forests is imperative to ensure they can remain healthy and productive. One tool that helps forest scientists to understand...
Estimating volume gains in genetically improved stands at rotation age is challenging because first-generation progeny tests in Douglas-fir were typically established to measure the relative growth performance of individual trees from open-pollinated parent trees. The overall goal of this dissertation research was to improve growth simulation of genetically improved Douglas-fir...
Budburst, the initiation of annual growth in plants, is sensitive to climate variation and is therefore used to monitor physiological responses to climate change. Budburst timing can vary between regions of an individual tree, but this phenomenon it is unaccounted for in current monitoring efforts and may contribute to the...
Tissue differentiation of the primary root and its associated
laterals is reported. Secretory elements are the first of the primary
tissues to mature. They appear to be located between the precursory
phloem and pericycle in the primary root, but are more closely
associated with the pericycle in long lateral roots....
The Pacific Coast form of Douglas-fir in natural forest succession
is an intermediate species thriving in the Coast Range and
Cascade Mountains of the Pacific Northwest. This species constitutes
26 percent of the standing timber in the United States, and 24 percent
of the nation's annual timber harvest. Characteristics of...
Mitotic activity in the vascular cambium was determined from
ten samples from a single internode in each of four Douglas-fir
[(Pseudotsuga menziesii (Franco.) Mirb.)]trees. Counts of interphase and mitotic nuclei from nine cores in each sample piece
were averaged and expressed as the frequency and mitotic index.
The sampling error...
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the tree species most widely distributed outside its natural range. The species has been introduced to Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir is an accepted and integral part of...
To obtain data on the decomposition of the forest floor, a battery operated electrolytic respirometer was developed making it possible to measure CO₂ evolution from field moist forest floor samples in situ independent of root respiration. Banks of four respirometers powered by two 12-volt batteries were installed in three old...
Experiments were conducted to determine if the plagiotropic
growth habit of rooted cuttings of Douglas-fir might result from a
system favoring the accumulation of indoleacetic acid in the adaxial
side of the shoot in response to vertical placement.
Actively growing excised branch terminals were subjected to
gravitational disorientation to determine...
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...
The relation of bud and cambial activity to root initiation and
elongation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)
stem cuttings was studied through two successive growth cycles.
Stem cuttings of current season's growth were taken periodically
from field-grown Douglas-fir trees to determine: (1) origin and
development of root initials; and...
A microscopic study was conducted on specific gravity wafers taken from standard tensile strength specimens of young growth Douglas-fir. Samples were studied to determine the effect of variables such as percent summerwood, fiber length and fibril angle on tensile strength of Douglas-fir. The sample specimens were picked so effects of...
• 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...
Three methods--radial compression strength, color indicators of decay and micro-toughness, an examination of tracheid fracture patterns, were evaluated for detection of early decay and for application to field use. Three-eighth-inch diameter plugs 3/4-inch long, cut from the sapwood and heartwood of a Douglas-fir pole free of decay, were decayed by...
Quantitative and qualitative information on the retention of chlorinated residues in chloropicrin treated wood is lacking. Retention of chloropicrin and its chemical breakdown products in wood, and the effects of chloropicrin treatment of wood on invading decay fungi are explored in this thesis. Chlorinated residues in amounts up to 1.5%...
The objectives of this study were to 1) characterize the layering in the wall of the Douglas-fir (Pseudotsuga. menziesii (Mirb. ) Franco) phellem cell, 2) determine the pitting present in this cell wall and 3) determine what compounds are present in the middle lamella of this cell. To accomplish the...
The relationships of several wood quality traits with seed origin
and phenological characteristics, measured at a young age, were
tested from six seed sources in a young Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) provenance plantation. The wood quality
traits measured were wood density, uniformity of wood density,
percentage latewood, fiber length,...
A study has been made of the kraft pulping properties of young Douglas-fir trees which were thinned from an experimental plantation. The purpose of the plantation study is to determine, whether two year old seedlings can be selected on the criteria of height and branch count for future desirable tree...
In their recent Canadian Journal of Forest Research Comment 368 article, Wilson and Oliver (2000) developed an equation for predicting the average ratio of height to diameter at breast height for the largest 250 trees/ha (H/DL250) in unthinned stands as a function of initial density and dominant height of the...
Pollen contamination was investigated in one block (block 4) of a 10-block Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard complex in western Oregon. Blocks (25 clones each) represent different breeding zones; thus, contaminant pollen sources not only included the adjacent natural stand of Douglas-fir, but also other blocks within the...
To determine whether shading increases drought-induced
root mortality by changing the chemical
composition of roots, I conducted an experiment in which
high and low light treatments in combination with high
and low soil moisture treatments were applied to
seedlings of Douglas-fir (Pseudotsuqa menziesii Mirb.
Franco). Because synthesis of suberin (a...
Sapling Douglas-fir trees on five sites in the Coastal and
Cascade Mountain ranges of Oregon were measured five times during
the year from the summer of 1977 through the spring of 1978 for
diurnal patterns of xylem water potential, stomatal conductance and
abscisic acid. Vapor pressure deficit and solar radiation...
First year survival of Douglas-fir seedlings outplanted in areas
characterized by intense vegetative competition is heavily dependent
on available soil moisture. To test this hypothesis, five distinct
classes of Douglas-fir planting stock were planted on the south slope
of McCulloch Peak in McDonald Forest in February of 1975. The
stocking...
The procedure of forest level harvest scheduling
incorporates many inputs of an uncertain nature. Forest
management planners must be aware of the possible effects of
the use of erroneous input information on the results of
their planning. With that knowledge they can better plan a
risk management strategy and make...
Douglas-fir (Pseudotsuga menziesii (Mirb. ) Franco) seedlings
of a high elevation Rocky Mountain source and a low elevation coastal
source were pretreated under both high and low intensity artificial
light in a growth chamber and outside in a cold frame. Net photosynthesis
was then measured at three ages, 6, 10,...
An understanding of the dynamics of individual tree and stand
growth, development, and structural patterns during the immature
formative years of a commercial species is essential to determine
correct thinning practices necessary to attain desired objectives.
This study compared a natural, medium-site Douglas-fir stand
and an adjacent similar stand released...
Douglas-fir bark was extracted with n-hexane. A light-colored
"wax-like" solid was recovered from the extract by evaporation of
the solvent. Chemically intact sterol esters and ferulic acid esters
were isolated from the "wax" without saponification or degradation
as had been necessary in former investigations. The characterization
of the intact esters...
Rates of apparent net photosynthesis were measured on a sample
of Rocky Mountain Douglas-fir consisting of eleven one-year-old seedlings
from each of the thirteen different seed sources. Secondary
observations of needle length, needle weight, and needle number
were also obtained. A formula derived through step-wise multiple
regression of the secondary...
Commercially collected Douglas-fir seed from a moist coastal
ecotype (LaPush, Washington) and a dry inland ecotype (Kaibab
National Forest, Arizona) were subjected to osmotic stresses ranging
from 0 to -8 atmospheres using Carbowax polyethylene glycol 6000
during imbibition and germination. To determine the effect of osmotic
stress on the initiation...