Experiments were conducted to determine if the plagiotropic
growth habit of rooted cuttings of Douglas-fir might result from a
system favoring the accumulation of indoleacetic acid in the adaxial
side of the shoot in response to vertical placement.
Actively growing excised branch terminals were subjected to
gravitational disorientation to determine...
Abstract: Genetic variation in drought hardiness traits and their genetic correlations with growth potential and17re1c6overy
traits were investigated in 39 full-sib families of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.)
Franco) from southwestern British Columbia. Seedlings of these families were grown in raised nursery beds and subjected
to three moisture...
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 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...
The seeds of Douglas fir, a representative of the gymnosperm
flora, were studied at six stages of germination to discern the structures
of food reserves and to study ultrastructural changes occurring
during germination in the embryo and resulting seedlings.
The materials were fixed in three fixatives, dehydrated with
ethanol series,...
Estimating volume gains in genetically improved stands at rotation age is challenging because first-generation progeny tests in Douglas-fir were typically established to measure the relative growth performance of individual trees from open-pollinated parent trees. The overall goal of this dissertation research was to improve growth simulation of genetically improved Douglas-fir...