Western white pine historically dominated northern Idaho’s forested landscape and was the Inland Empire’s most economically important tree. White pine blister rust, caused by the exotic fungus Cronartium ribicola, played a principal role in the decline of western white pine. The pathogen causes branch and bole cankers, which usually girdle...
The Tenino stand, located on the Warm Springs Indian Reservation (WSIR) near Warm Springs, Oregon, is being considered for treatment that will promote longterm forest health, fire resiliency, and wildlife habitat. The management direction for this area is outlined in two WSIR documents: 1) Integrated Resources Management Plan for the...
A series of studies, in three western Oregon Douglas-fir plantations, was conducted to understand the physiological impacts of Swiss needle cast on Douglas-fir physiology. Four aspects of the disease complex were investigated: fungal colonization and assessment, plant-water relations, carbon assimilation and interaction with climate. Several techniques were developed and used...
Improved accessibility in remote noble fir (Abies procera Rehd.) stands and the
realization of the value of noble fir wood have led to increased pressure to enter and
actively manage noble fir stands in Oregon and Washington. This study examined the
incidence of infection and decay caused by Heterobasidion annosum...
Concerns over the possibility of exotic pest
introductions from eastern Russia to the West Coast of the United States due to proposed log imports raises the question of the effectiveness of possible mitigation measures. Toxicity of methyl bromide to representative pathogenic fungi was tested by exposing Armillaria ostoyae, Heterobasidion annosum,...
This study examined the relationships between the frequency of occurrence and severity of Douglas-fir dwarf mistletoe (Arceuthobium douglasii Engelmann), environmental and stand conditions, and plant communities in the Southern Oregon Cascade Mountain Province. Data for the study was collected from the same ecology plots that were previously used to define...
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...
Tree wounding can lead to decay in roots, stems, and branches of
trees. Wood decay is caused by various species of fungi that enter
trees through wounds or small branches.
Root disease fungi attack and destroy the tree’s root system, resulting in growth loss, decay, death, or wind throw of infected trees. Trees with root disease also are more susceptible to pests, especially bark beetles. On the other hand, root diseases are a component of the forest ecosystem and play...