Laminated root rot of Douglas-fir (Pseudotsuga menziesii (Mirb.)
Franco) caused by the fungus Phellinus weirii (Murr.)Gilbertson was
studied in two successive stands in the Oregon Coast Range. Damage
due to the disease in a 60-year-old second-growth stand was compared
with incidence in the preceding 300-year-old stand on the same site....
In 1993 The Oregon Department of Environmental Quality developed a Cross-media Comparative Risk Assessment model to address certain regulatory concerns. Due to budget constraints the model was never beta tested. Now in 1995, the X-media project has been reopened, and the model revised, and tested. Specific revisions include: 1) Upgrade...
Full Text:
AN ABSTRACT OF THE THESIS OF
David S. Borys for the degree of
Coring at ODP Sites 859, 860, and 861 near the Chile Triple Junction failed to recover anticipated gas hydrate that was inferred
to be present from two lines of geophysical evidence: pre-cruise observation of a weak to strong bottom simulating reflector (BSR)
marking the predicted base of the gas-hydrate stability...
The subduction of the oceanic spreading center at the Chile Triple Junction is marked by a substantial thermal perturbation
and marked changes in the hydrogeologic and aqueous geochemical regimes in the overthrust plate. Ridge subduction substantially
changes the fluid chemistry in the wedge through variably hydrating the oceanic basement, accretionary...
Verticicladiella wageneri Kendr. is a vascular wilt pathogen of
Douglas-fir in the Pacific Northwest, The disease is characterized by
black staining of colonized sapwood; crown symptoms are those typical
of a wilting syndrome. Histopathological studies revealed that the
pathogen is limited to the xylem but causes vascular dysfunction in
both...
Alaska-cedar (Chamaecvparis nootkatensIs (D. Don) Spach) is a
valuable tree that is suffering from a serious decline and mortality of
unknown cause throughout southeast Alaska. Epidemiological and
pathological studies were initiated to determine if a pathogen is the
primary cause of this problem. By examining old aerial photographs and
by...
Described as one of the most destructive pathogens of agricultural crops and forest trees, Phytophthora is a genus of microorganisms containing over 100 known species. Phytophthora alni has caused collar and root disease in alders throughout Europe and a form of the species has recently been isolated in North America....
The root disease fungus Inonotus tomentosus, common in the old
growth boreal forests of British Columbia, poses a threat to the
health of second growth forests established on sites with a previous
history of root disease. Colonized stumps occur in groups of 1 to 6;
the groups are clumped within...
Within the Pacific Northwest, USA, root diseases of conifers are a major forest health concern. These diseases are primarily caused by basidiomycete fungi. These fungal associates play a vital role in carbon sequestration but also have a significant negative economic impact within the timber industry. As a result, research on...