Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the
tree species most widely distributed outside its natural range. The species has been introduced to
Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir
is an accepted and integral part of...
Full Text:
Douglas-fir
Denis P. Lavender and Richard K. Hermann
The
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the
tree species most widely distributed outside its natural range. The species has been introduced to
Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir
is an accepted and integral part of...
Full Text:
Douglas-fir
Denis P. Lavender and Richard K. Hermann
The
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the tree species most widely distributed outside its natural range. The species has been introduced to Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir is an accepted and integral part of...
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...
Perennial woody plants have a complex annual cycle keyed to the environment. Temperate plants have an annual dormant period commonly broken by exposure to low temperatures, although daily photoperiods of 16 hours or longer may partially substitute for the chilling. Shoot growth in the spring is normally stimulated by rising...
The effect of lifting Douglas-fir seedlings from the nursery bed
and replanting them, either immediately or after storage at 2 C for
periods up to six weeks, was investigated through a series of experiments
conducted in controlled-environment chambers and under field
conditions. Seedlings lifted prior to December, or after buds...
