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...
Pine needle blight of Pinus ponderosa Laws. caused by
Elytroderma deformans (Weir) Darker is recognized by changes in
the needles, in the bark and in the development of the branches.
Anatomical studies of the host-parasite relation have been made previously
on young pine tissue up to four years of age...
Longevity and germination of seed of western dwarfmistletoe (Arceuthobium campylopodum Engelm. f. campylopodum) of ponderosa
pine (Pinus ponderosa Laws.) was investigated to determine:
1) the influence of humidity and temperature on seed viability and
deterioration during storage; 2) the physiology of seed dormancy;
3) the composition of seed reserve food...
This dissertation describes arthropod responses to and effects on decay processes in ponderosa pine, a dominant forest canopy tree in northern California. We used both descriptive and experimental field techniques to establish how arthropod assemblages depend on and are important to the disintegration of woody structures in forests of this...
Root rot of ponderosa pine caused by Armillaria mellea was
studied in a pine forest that had been under management for 30 years
in Klickitat County, Washington. Information sources included
disease survey, detailed observation and description of specific
disease situations, and examination of roots in situ and removed.
Roughly circular...
In 1967, Lophodermella morbida Staley and Bynum, a recently described
hypodermataceous needle-cast fungus, became destructively
epidemic in a knobcone pine (Pinus attenuata Lemm.) plantation in
Del Norte County, California, and in several ponderosa pine (P.
ponderosa Laws.) plantations in western and southwestern Oregon.
This thesis presents information on this currently...
The purpose of this study was to study in some detail
host factors which influence the population dynamics of
bark beetle. The dissertation objectives were to ascertain
the applicability of utilizing osmotic pressure
values and relative turgidity values of phloem tissue as
indicators which reflect upon the physiological profile
of...
Whitebark pine (Pinus albicaulis) is an iconic North American high-elevation tree species currently threatened by climate change, mountain pine beetle, and white pine blister rust (WPBR), a lethal disease caused by the non-native fungal pathogen Cronartium ribicola. In collaboration with the USDA Forest Service Dorena Genetic Resource Center, germplasm was...