Oscilloscope display of modification of a square wave signal passed through stem tissue was evaluated as a means of detecting depth of dormancy and survival potential of coniferous seedlings. Trace form did not change during release from deep dormancy in Douglas fir. This release was judged by observing speed of...
The relative freezing resistance of tissues in the stem, foliage and buds of terminal twigs from Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was investigated at about ten-day intervals from summer until the following spring. Tissues from growing twigs collected before development of dormancy had no freezing resistance and were killed immediately...
Root biomass studies were conducted in an old-growth stand of
conifers in the western Cascades of Oregon. The root systems of three
Douglas-firs (Pseudotsuga menziesii var. menziesii (Mirb. ) Franco)
with diameters at breast height of 94, 110, and 135 cm were excavated
and weighed to provide a basis for...
An apparatus was designed to permit freezing tests of
needles and other tissue parts from coniferous trees under
controlled rates of temperature change with time. The design
is based on the principle of a balanced system of refrigeration
demand and heat input to achieve a steady temperature state.
The apparatus...
Western redcedar, western hemlock, and Douglas-fir seedlings were transplanted into pots in one of two soils representative of high and low levels of available NO3 (and total N). The soils were collected from sites at Cascade Head (Oregon Coast) and Wind River (Washington Cascades). Whole plant and component relative dry...
Cercocarpus ledifolius (curlleaf mountain- mahogany), a small, hardwood evergreen tree, was studied to provide information on germination and initial seedling growth characteristics, and the species' relationship to its environment.and associated vegetation. Exceptional germination for this species resulted from both a wet cold treatment at 4°C for 170 days (88 percent),...
Fine roots are a dynamic component of Douglas-fir ecosystems. Changes in standing crops indicate that fine roots require a major portion of the stand's energy resources to fulfill their role in the
functioning of these systems. We observed standing crops of live and dead fine (< 1 mm diameter) and...
First year survival of Douglas-fir seedlings outplanted in areas
characterized by intense vegetative competition is heavily dependent
on available soil moisture. To test this hypothesis, five distinct
classes of Douglas-fir planting stock were planted on the south slope
of McCulloch Peak in McDonald Forest in February of 1975. The
stocking...
The succession of plants over a period of 25 years was analyzed on clearcut areas in the western Cascades of Washington and Oregon. Thirty-three paired burned and unburned plots were reexamined in 1975. Data were combined with records from prior examinations by Morris (1970). Cover trends of six major brush...
Shear wave attenuation measurements were made
using ceramic bimorph transducers to excite transverse
vibrations in a cylindrical column of unconsolidated
sediment. Three different water-saturated
sediments were used in an attempt to determine the
effects of grain shape and sorting on the frequency
dependence of attenuation. The mean grain size of...