Karyotype analyses have been madeon only two on the six recognized species in the genus Pseudotsuga, Douglas-fir (P. menziesii) and bigcone Douglas-fir (P. macrocarpa). In this
study, a comparison was made between the karyotypes of Douglas-fir and Formosan Douglas-fir (P. wiloniana). The basic chromosome number of the Formosan Douglas-fir was...
A rapid and efficient procedure that required no partitioning was developed for the purification of abscisic acid (AbA) from the needles of Douglas-fir seedlings. Extracted needle pigments were removed by a
PVP column and the eluted AbA was concentrated on a DEAE column. The AbA was eluted from the DEAE...
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...
Foliage of Douglas-fir seedlings [Pseudotsuga menziesii (Mirb.) Franco] from two contrasting environments was sampled during progressive stages of two consecutive cycles of induced drought for leaf resistance, plant water potential , and abscisic acid content (ABA). One group of seedlings was placed in a controlled environment room while another group...
The Washington State Department of Natural Resources' Comprehensive Tree-Volume Tarif Tables are a set of preconstructed local volume tables. This can increase "on plot" efficiency since only diameters are necessary to obtain volumes after the proper table for the given diameter/height relationship is accessed. The tables are accessed and indexed...
Nitrogen, phosphorus and sulfur concentrations were measured in the soil, foliage and litter of Douglas-fir growing in pure Douglas-fir and mixed conifer stands. On four sites of contrasting fertility and climatic conditions, plots had been modified by the introduction of alder, thinning, or by a single application of nitrogen fertilizer...
Many higher plants have mycorrhizae associated with their roots. These structures are often essential for survival and growth (Harley & Smith 1983). Mycorrhizae are known for the abilities to enhance nutrient absorption. While nitrogen-fixing organisms are found as components of the mycorrhizosphere, mycorrhizal fungi are not presently known to fix...
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...
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...
Five different test methods to determine the parallel-to-grain shear
strength of Douglas-fir structural lumber were compared. Four methods
assessed the shear strength of lumber sections having a full nominal two by
four inch cross-section. These were: three-point bending, four-point bending,
five-point bending, and torsion. The fifth method was the ASTM...
Laminated root rot of Douglas-fir (Pseudotsuga menziesii (Mirb.)
Franco) caused by the fungus Phellinus weirii (Murr.)Gilbertson was
studied in two successive stands in the Oregon Coast Range. Damage
due to the disease in a 60-year-old second-growth stand was compared
with incidence in the preceding 300-year-old stand on the same site....
The purpose of this thesis was to develop a suitable
multiple regression equation for making estimates of diameter
inside bark at various heights up the bole in
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)tree.
Data on 237 and 302 trees from Black Rock Forest Management
Research Area, Polk County, Oregon, and scattered...