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...
Profitable, even-aged forest management depends on the early establishment
and rapid growth of each new forest crop. These, in turn,
require that the young trees have access to an adequate supply of
native resources of moisture, nutrients and light. In Mediterranean-type
climates, competition for soil moisture is the most serious...
To investigate the movement of elements (N, P, k, Ca, and Mg) from the tree crowns by natural litterfall and leave wash, plots were established on six 450 year-old growth stands at the H. J. Andrews Experimental Forest. The following are the results of the data analyses. Elemental concentrations contained...