Indentation hardness tests were made on sections of 211 pieces
of Douglas fir and 208 pieces of Western hemlock at a moisture content
of about 11 percent. Specific gravity and visual-density evaluations
were also determined.
Correlation coefficients for linear regression of density, as
measured by specific gravity, on average standard...
It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species...
Douglas fir bark fines which contained 74.8 percent
of Klason lignin and 70.2 percent of one percent sodium
hydroxide solubility and decayed Douglas fir wood which
contained 53.9 percent of Klason lignin were subjected to
ethanolysis. A slight modification of the Hibbert's
ethanolysis procedure was used. The monomeric compounds
present...
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,...
Ninety-one species of birds were surveyed in grass/forb, early and late shrub/sapling, pole, and medium sawtimber stages of young-growth Douglas-fir in northwestern California; patterns of bird distribution and abundance were related to habitat conditions and even-age silvicultural treatments. Seven species (band-tailed pigeon, western wood pewee, dusky flycatcher, western bluebird, fox...