doi: 10.1093/wjaf/10.1.z5pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1995 by the Society of American Foresters
doi: 10.1093/wjaf/10.1.z1pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1995 by the Society of American Foresters
Knowe, Steven, A.;Carrier, Byron, D.;Dobkowski,, Alex
doi: 10.1093/wjaf/10.1.5pmid: N/A
Abstract Diameter and height growth of 7- to 11-yr-old Douglas-fir (Pseudotsuga menziesii) were examined in relation to bigleaf maple (Acer macrophyllum) competition. Growth models were developed for plantations in Oregon and Washington by joining a distance-dependent model with a model that excluded competition effects. The fitted equations were based on Douglas-fir size at plantation age 7 yr and distance from the stump and crown diameter of the bigleaf maple clump. The models suggest that bigleaf maple clumps between 5.7-14.6 m from planted Douglas-firs decrease the latter's dbh and height growth, and that this decrease becomes greater with increasing size of the clump. A procedure is suggested to use the models to guide vegetation management prescriptions on sites with bigleaf maple sprout clumps. West. J. Appl. For. 10(1):5-11. This content is only available as a PDF. © 1995 by the Society of American Foresters
Fight, Roger, D.;Johnston,, Stuart;Briggs, David, G.;Fahey, Thomas, D.;Bolon, Natalie, A.;Cahill, James, M.
doi: 10.1093/wjaf/10.1.12pmid: N/A
Abstract Once site and genetic stock are selected, management of stocking, rotation age, and pruning are the principal means available to foresters to affect wood quality and value in stands of coast Douglas-fir (Pseudotsuga menziesii var menziesii). Financial evaluation was used to test whether or not improvements in wood quality and value by these means justify the costs of doing so. This analysis showed in general that improving quality through high levels of stocking or extending rotations were costly ways to improve wood quality while pruning was a cost-effective way to improve wood quality. West. J. Appl. For. 10(1):12-16. This content is only available as a PDF. © 1995 by the Society of American Foresters
Hibbs, David, E.;Emmingham, William, H.;Bondi, Michael, C.
doi: 10.1093/wjaf/10.1.17pmid: N/A
Abstract Responses of red alder (Alnus rubra Bong.) to thinning were observed at two sites in the Oregon Coast Range. Five years after thinning in the 20-yr-old stand, mortality was observed only in control plots. Diameter growth of crop trees increased up to 54% with thinning. Trends toward less height growth at wider spacings and increased growth in basal area compared to controls appeared to be developing in thinned plots. Ten years after thinning in the 14-yr-old stand, the problems of flashback seen at year 5 in the chemically thinned plots had largely been overcome. Reduction in height growth in all thinned plots had been overcome. Net basal area growth was up to 60% greater in thinned treatments. Thinning appears effective for 10 to 15 yr in the narrow spacings and 15 to 20 yr in the wide spacings. West. J. Appl. For. 10(1): 17-23. This content is only available as a PDF. © 1995 by the Society of American Foresters
doi: 10.1093/wjaf/10.1.24pmid: N/A
Abstract Shade duration and shrub composition in microsites with naturally regenerated Douglas-fir seedlings (Pseudotsuga menziesii var. glauca) were compared to randomly located control plots without seedlings in hot, dry group selection cuts in the southernmost Boise National Forest. Shade duration was estimated using a sighting device which allowed quantification of the degrees of the sun's arc intercepted by timber, shrubs, or other obstructions. Measurements were standardized for the median date for summer high temperatures. Seedlings received more whole-day (P<0.001) and afternoon (P<0.001) shade than control plots, and seedlings on southern exposures received more shade than those on other aspects. Seedling plots had more shrub cover than control plots (P<0.007). However, of nine shrub species examined, only buckbrush exhibited a significantly positive association with seedlings. Soil surface temperatures under buckbrush were reduced more than under other species, and unshaded surfaces remained above 50°C for extended time periods. These results suggest that natural regeneration of Douglas-fir may be enhanced by harvest practices and site preparation methods which provide shade during critical stages of germination and early seedling establishment. West. J. Appl. For. 10(1):24-28. This content is only available as a PDF. © 1995 by the Society of American Foresters
Alig, Ralph, J.;Adams, Darius, M.
doi: 10.1093/wjaf/10.1.29pmid: N/A
Abstract Nonindustrial private timberlands in western Washington have high productive potential and contribute harvest amounts somewhat more than proportional to their area. Of all private ownerships they are influenced the most by land use shifts and are affected in important ways by forest practice regulations. About 1 million acres of nonindustrial private timberland contain opportunities for timber management intensification that would increase net growth, in many cases offering attractive financial returns. Significant increases in timber growing investments could double softwood harvest levels in the long term. A combination of forest practice regulations to lengthen rotations by 10 yr and a 15% setaside of other timberland with older timber could reduce short-term softwood harvest levels by one-third. West. J. Appl. For. 10(1):29-35. This content is only available as a PDF. © 1995 by the Society of American Foresters
Keegan III, Charles, E.;Fiedler, Carl, E.;Stewart, Fred, J.
doi: 10.1093/wjaf/10.1.36pmid: N/A
Abstract Harvest costs were estimated for New Forestry silvicultural prescriptions designed for application on national forest lands in western Montana. Estimates were derived using an expert opinion format and were compared using constant dollars with actual 1991 costs based on more traditional prescriptions. Costs were developed for three major logging systems(tractor with hand-felling, tractor with mechanical-felling ,and uphill skyline with hand-felling) and four major stand types[lodgepole pine( Pinus contorta), mature ponderosa pine( P. ponderosa)/Douglas-fir(Pseudotsuga menziesii), second-growth pine/fir,and mixed conifer].Average harvest costs for New Forestry prescriptions ranged from no increaset o 48% ($72/mbf)higher.In light of stumpage price increases of >$200/mbf since 1991, these increased costs should be a minor factor in determining the feasibility of future timber harvest.West.J.Appl. For. 10(1): 36•42 This content is only available as a PDF. © 1995 by the Society of American Foresters
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