Two-year-old ponderosa pine (Pinus ponderosa Laws.)
from two seed sources were grown at two nurseries. The
Fremont seed source was raised at Bend and Stone Nursery;
the Ochoco was grown at only the Bend Nursery. The
seedlings were fertilized in late September-early October
with nitrogen (N) or nitrogen plus potassium...
The hypothesis is explored that lodgepole pine at the seedling emergence period is more resistant to low temperatures than ponderosa pine. Differential tolerance between species to low temperatures is then related to the prevalence of lodgepole pine in frost pocket areas in central Oregon to the exclusion of ponderosa pine....
A comparative study was made of Pinus ponderosa Laws, and
Arceuthobium campylopodum Engelm. f . campylopodum to determine
(1) whether or not the parasite or parasitized tissues accumulate
abnormal concentrations of minerals, (2) whether or not there
was evidence of a blockage of mineral translocation in the phloem
Seven sites of uniform topography and soil were selected within
a self perpetuating ponderosa pine forest found on the eastern
flank of the central Oregon Cascades. These plots were located along
a vegetational gradient caused mainly by an orographic rain shadow.
Data gathered included density, frequency, and cover for all...