The authors varied the number of red alder retained with 300 Douglas-fir per acre on a high-quality site in coastal Oregon. Alder densities of 0, 20, 40, and 80 per acre were tested. The authors' fifth treatment eliminated nitrogen-fixing alder, but substantial nitrogen fertilizer. Treatment 6 had neither thinning nor...
Physiology and genetics of drought hardiness were investigated in two-year-old coastal Douglas-fir seedlings from 39 full-sib families obtained from coastal British Columbia and grown at Oregon State University, Corvallis, Oregon. The seedlings were subjected to three drought treatments (control, moderate, and severe drought) in their second growing season (June through...
Modified selection thinning has been utilized by some non-industrial foresters in Douglas-fir forests of Western Oregon and Washington for at least 35 years. This silvicultural strategy has not been tested, but has often been associated with reduced volume production and other undesirable effects. It continues to be used on many...
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....
Understory conifer regeneration needs to occur beneath conifer-dominated
canopies if two-storied or uneven-aged structures are to be considered for western
Oregon Coast Range stand management. To ensure adequate numbers of seedlings
to meet stocking or habitat structure objectives, planting may be a solution. We
undertook a multi-level study to determine...
The response to various levels of stand density by natural Douglas-fir regeneration, shrub and sprouting hardwood species was studied in the mixed-evergreen-forests of southwest Oregon. Partial-cut old growth (harvested 22-31 years prior) and thinned evenaged (harvested 9-17 years prior) stand types were used as surrogates for intentionally managed uneven-aged stand...
The fungi that cause mold and stain of freshly sawn lumber result in millions of dollars in losses to the forest products industry. Stain and mold are typically prevented by either kiln drying or by application of a topical fungicide. While these treatments are effective, kiln drying is costly and...
It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species...
This study examined the abundance, size, growth, and age of advance regeneration
Douglas-fir, beneath an eighty year-old overstory at a single site on plots subjected to different overstory thinning treatments. Treatments consisted of keeping overstory basal area within upper and lower limits for periods of 12-17 years which, depending upon...