The effects of clonal variability, crown position of cones, and top-pruning of ramets to reduce height growth, on 1) the proportion of viable self-fertilized progeny (s) and 2) the proportion of filled seeds (PF), were investigated in a 20 year-old Douglas-fir (Pseudotsuga menziesii [Mirb.1 Franco) seed orchard. Cones were collected...
The main objective of this study was to evaluate the interaction between
herbaceous competition, fertility, and seed source on Douglas-fir survival and
growth. A secondary objective was to evaluate the effect of these various factors
on the production of lammas shoots and the selectivity of deer browse. Finally,
the role...
Effects of four inbreeding levels (F = 0, 0.125, 0.25, 0.5) and
two supplemental mass pollination (SMP) methods (agitation of
naturally shedding pollen with "air blaster" and pollen application
from large "pollen wand" atomizer) were evaluated on seed of trees
from eleven full-sibling Douglas-fir (Pseudotsuga menziesii [Mirb.]
Franco) families in...
This study had three objectives: (1) to determine the degree to which within-source genetic variation and genetic correlations differ among elevational sources of Douglas-fir [Pseudotsuga menziesii (Mirb). Franco var. menziesii]; (2) to ascertain the degree to which phenotypic stability differs among and within elevational sources; and (3) to compare the...
Germination and survival of Douglas-fir on seedbeds of unburned,
lightly burned, and severely burned soil, charcoal, litter, and sawdust,
exposed to 100, 75, and 25 percent of full light, were studied on a
south-facing clearcutting in the Coast range of Oregon.
Irrespective of exposure to light, germination was best on...
The impact of various factors on seed production in a
Douglas-fir (Pseudotsuga menziesii) seed orchard in
western Oregon was examined by monitoring the fate of
seeds in thirty cones, stratified into three crown levels,
on each of ten trees during the 1984 growing season.
Cones were examined monthly between April...
To determine if squirrels (Sciurus douglasii var.) cut cones before the seeds are ripe, a series of collection points was established in the Willamette Valley and the Cascade Mountains in the summer of 1954. The areas were inspected at intervals during August, September and October of 1954, and freshly cut...
A 3-year evaluation of Douglas-fir cones in Montana and Yellowstone National Park, Wyoming, showed the western spruce budworm, Choristoneura occidentalis Freeman, and midges were the most common and injurious insects found each year. Injury was so severe at some plots that no sound seeds could be found.
