Two-year-old ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings from two Oregon seed sources were lifted three times in the fall, stored below freezing (-1.5°C), and compared to seedlings that were handled conventionally (spring lifting followed by short-term cold storage, 2-4°C). Based on patterns of budbreak in a greenhouse and...
This thesis research examines the effects of film-forming antidesiccants applied to dormant pondexosa pine (Pinus ponderosa Dougl.) seedlings after being lifted and to actively growing seedlings. The basic proposition was that antidesiccants would have a positive effect on reducing water loss in ponderosa pine seedlings. In order to evaluate the...
The objective of this project was to investigate the fate of ponderosa pine regeneration from seed to established seedling, and to determine the relative influences of several important stand elements on those fates. The project was carried out in a series of observational and experimental recruitment studies in central Oregon....
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
because of...
The effects of dwarf mistletoe on fuel in precommercial ponderosa pine stands: Dwarf mistletoe and healthy stands were sampled by vertical planar intercept and whole tree biomass sampling techniques to measure
fuel loading in ground and crown fuels. Differences in size, distribution, and vitality of fuel were shown to depend...
Geographic variation was investigated among 225 locations from five geographically disjunct regions in central Oregon. Characters included: germination speed and uniformity in two test environments
differing in stratification period and incubation temperature; weight, three dimensions and three 'angles' of seeds; weight and three dimensions of wings; cone length and scale...
Root rot caused by Armillariella mellea creates roughly circular
disease centers of infected dead and dying trees in the younggrowth
ponderosa pine forest under study. Research objectives concerning
chemical control of the disease were: 1) to test the
effectiveness of certain chemicals in protecting living pines adjacent
to disease centers...
Armillariella mellea (Vahl. ex Fr. ) Karst. was grown aseptically
in hazel stems (Corylus cornuta var. californica) which were used in
the forest to infect 290 ponderosa pines (Pinus ponderosa Laws.)
which had been "stressed" in five different manners plus two control
groups. All trees were inoculated twice giving a...
