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...