The resistance of a leaf to molecular gaseous diffusion
is an important physiological response. Control of
leaf resistance enables a plant to control its transpired
water loss and regulates photosynthesis.
Four study sites representing a gradient in available
moisture and evaporative demand, were chosen in western
Oregon for the study...
Clearcutting is a sound silvicultural practice when exercised
in the proper environmental location. Foresters have learned through
bitter experience that clearcutting Douglas-fir forests, located on
droughty south-facing slopes, often leaves uncorrectable regeneration
problems. Thousands of acres of unproductive grass and brush throughout
the Douglas-fir region are unavoidable reminders of inappropriate...
In a mountainous region of southwestern Oregon where temperature, moisture and nutritional status of forest communities have already been classified, the influence of tight upon conifer growth and plant distribution was investigated. Light, measured in calories cm day' (400-700 nm) during clear summer days was used as an index to...
The control that stand leaf area exerts upon individual tree vigor was tested on a heterogeneous, even-aged Douglas-fir stand infected by Phellinus root rot. Tree vigor, or growth efficiency ratio, was defined as the current basal area growth per unit of leaf area. Because of a close relationship between sapwood...
Lodgepole pine seedlings were used to test a general hypothesis of how water and nitrogen stress affect a plants' monoterpene composition. Four treatments, consisting of high and low levels of both water and
nitrogen, were applied to the trees. Growth measurements, consisting of shoot and needle lengths, needle fresh weights...
Spectroradiometric analyses were made to examine the light filtering capacity of coniferous forests and to establish the lower light energy limits for growth of Pseudotsuga menziesii (Mirb. ) Franco, Abies concolor (Gord. and Glend.) Lindi. and Pinus ponderosa Dougi. Visible energy(400-750 nm) was recorded at 48 points under four mixed...
In any electrical system no part is stronger than the weakest link. It is very important that the insulation of the transmission line be kept intact at all times. For this reason any improvement in the design or manufacture of insulators would be desirable.
The object of this research was...
