Published April 1969. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Phaeocryptopus gaeumannii is a pathogenic fungus on Douglas-fir needles which has become a serious threat to timber production in the last decade along the Oregon coast This research was undertaken to describe the general biology and pathology of F. gaeumannii on Douglas-fir needles and how environmental variables affect fungal development....
The structuring of canopy arthropod communities was reviewed and investigated in relation to tree species diversity and its component factors, interspersion of different species and density of each tree species. Fifteen treatments of Douglas-fir (Pseudotsuga menziesii) and red alder (Alnus rubra) (various densities and proportions of each) were randomly assigned...
Disease is often overlooked as a natural disturbance agent in plant communities. This study examines what effects, if any, a disease-mediated disturbance has on the plant community as a whole in old-growth and mature forests of western Oregon. Phellinus weirii (Murrill) Gilbertson (Family: Hymenochaetaceae) is a native root-rotting pathogen that...
Douglas-fir, Pseudotsuga menziesii and white alder,
Alnus rhombifolia, species that are prevalent in the
Pacific Northwest, were fed to larvae of the gypsy moth,
Lymantria dispar L. Gypsy moth larvae from different
familial lines (egg masses) from a single geographic
population were evaluated on these hosts. The larvae
were fed...
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...
The relationship between the level of Phaeocryptopus gaeumannii (Rohde) Petrak colonization and severity of Swiss needle cast (SNC) symptoms, the possibility of early testing of Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) for SNC tolerance, and geographic variation in coastal Oregon with respect to SNC tolerance were investigated. Comparisons between...