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...
Methanolic extracts of the dormant Douglas-fir shoots (buds, leaves, and stems) were fractionated by solvent partitioning (sodium bicarbonate-diethyl ether). The acidic portion of the extract was subjected to column (Sephadex LH-2O, Silica Gel and Polyvinylpyrrolidone), preparative thick-layer and gas-liquid chromatography.
Fractions collected from chromatographic separations were collected and tested for...
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...
Definitive evidence for the occurrence and seasonal variation of indole-3 -acetic acid (IAA) in shoots 0 DougLas-fir (Pseudotsuga rrienztesii (Mirb. ) Franco) was sought. Collections obtained in December and June were extracted by solvent using methanol arid diethyl ether arid by certtrtfugatiori. Extraction by ceritrifugation appeared to be twice as...
During the past 20 years, repeated thinning of a Douglas-fir forest, now 65 years old, has allowed desired limits of basal area to be maintained. In the process, the understory environment has altered sufficiently to allow Douglas-fir reproduction to establish in abundance. The forest is located on the east side...
When trees from 16 populations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco. var. menziesii) were grown at ten geographically diverse locations for seven years, those from a Vancouver Island source were among the top three for height growth on nine of the ten plantations (Rowe and Ching, 1974). In contrast, growth...
A sample of 181 wind pollinated families, representative of the range of environmental conditions occupied by Douglas-fir in northern California, was used as a basis for studying variation in early height growth, phonology, and seed characteristics. Seedlings were raised at Corvallis, Oregon, in a nursery trial designed to evaluate response...
Douglas-fir seedlings of a single seed source were grown in a nursery under three levels of light intensity: 9, 44, and 100 percent of full light. Growth over an entire growing season was monitored in terms of proportionate distribution of dry matter to shoot and root systems. This was replicated...
Net photosynthesis was measured for photosynthetic light efficiency and capacity on two-year-old plants from eight different seed sources in three measurement periods. The measurement periods corresponded to the physiological periods 1) prior to bud swelling, 2) after needle elongation, and 3) predormancy. Measurement period differences in both photosynthetic efficiency and...
The objectives of this investigation were to measure the seasonal and diurnal variations of starch as well as to relate these variations to growth of the trees. This study also microscopically examined the
needles to determine if starch exists in granular form in Douglas-fir. The objectives were designed to gain...