My objectives were to investigate the correlation of height and diameter growth in young Douglas-fir (Pseudotsuga menziesii) plantations with stand density, and to determine the effects of stand density on the canopy boundary layer conductance (g[subscript]ac) and microclimate characteristics of young Douglas-fir plantations. I measured annual height (h) and diameter...
To bring together in systematic and usable form the bulk of the information dealing with Douglas fir logging costs thus far acquired, so as to make it accessible, is the object of this publication.
The last outbreak of the Douglas-fir tussock moth, Hemerocampa pseudotsugata McD., in the Northern Region subsided in 1965. Tussock moth populations were not detected again until 1970 when ornamental spruce were defoliated in Spokane, Washington, and Poison and Missoula, Montana.
This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well...
In forest trees from temperate and boreal regions, cold acclimation is an important
adaptive trait that involves changes in gene expression and physiology. Genecological, quantitative genetic, and QTL studies have been used to study the genetics of cold acclimation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), but the genes responsible for...
Douglas-fir (Psudotsuga menziesii (Mirb.) Franco) seedlings were outplanted on eight dates (every three weeks from mid-August 2005 through mid-January 2006). On each plant date, seedlings from a conventional dormancy (CONV) induction treatment, including moisture and nutrient stress, and a shortened daylength (SD) treatment were outplanted on three western Oregon sites...
Early in the establishment of Pacific Northwest conifer plantations, herbaceous weeds often decrease seedling growth through competition for soil moisture during the dry summer months. Critical period studies have reported that reductions in competitive weed cover are necessary during the initial years of establishment to avoid reductions in seedling growth....
This study characterized the nature and dynamics of interference in mixed red alder
(Alnus rubra Bong.)/Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands in the Pacific Northwest, USA. Long-term spatial and tree measurements from the Cascade Head (CH) and H.J. Andrews (HJA) Experimental Forests in western Oregon and Delezene Creek (DC), Washington...
An evaluation to establish baseline data on forest insect and disease activity near a magnesium plant under construction in northeastern Washington was initiated in 1974. The plant will emit significant amounts of sulfur dioxide. Data indicates that several fungal and insect species are at low populations. Needle retention appears normal...
The insects that invade a dying or dead tree are the immediate cause of death and the principle mediators of early stages of decomposition of the tree. These insects form a large and complex community, the species
components of which are restricted to particular habitats. A study of
the insect...
The attack spatial pattern of the Douglas-fir beetle, Dendroctonus
pseudotsugae Hopkins was shown to be regular within a given subarea
of bark on its host, Pseudotsugae menziesii (Mirb.) Franco. Empirical
arguments were advanced which indicated the uniform spacing of attacks
was the result of a beetle controlled spacing mechanism dependent...
Felled second-growth Douglas-fir trees in western Washington were used
to determine the attack distribution and develop a sampling technique
for an endemic Douglas-fir beetle, Dendroctonue peeudotaugae Hopk.
(Coleoptera: Scolytidae) population. The attack density varied by
circumferential position. The lowest density was on the upper bole
and the highest on one...
Mammal and bird damage recorded on Douglas-fir and ponderosa pine plots-randomly established in Oregon and Washington during 1963-64, then observed for 5 to 10 years-was evaluated for impact on survival and growth. In all, 194 plots were installed, and 10 of the 110 seedlings on each plot were caged to...
After three-quarters of a century of introduction of 152 conifer and broadleaf species,
no promising candidate exotic was found for the Douglas-fir region. Growth curves
spanning 50 years or longer are figured for many species. Firs, pines, larches, spruces,
hemlocks, and cedars originating in northwestern North America had superior growth...
Intensive studies of the mineral cycling process in young-growth Douglas-fir stands have been in progress at the R. H. Thompson Research Center since 1966. During this time, a substantial body of information has been collected on the amounts, pathways, rates
of transfer, and mechanisms that control transfer of elements in...
Preliminary results of a comprehensive study of hydraulic fluctuations in Douglas-fir (Pseudotsuga menziesii) stems in response
to plant water status and environment are presented. Diurnal changes in stem circumference near DBH of a dominant Douglas-fir were monitored using automated band dendrometers. Measurements of transpiration rate, internal moisture stress and stomata...
Foresters care about site productivity and stem quality in Douglas-fir plantations for many reasons. The profitability of forest land and the economic returns on silvicultural investments are directly related to site productivity. Thus, understanding the relationships among Douglas-fir productivity, stem form and site characteristics is important economically. My objective was...
Regression models of height growth and survival were fitted to aggregate data for trees, protected and not protected from animal damage, that had been surveyed on Douglas-fir and ponderosa pine plantations in Oregon and Washington. Animal damage significantly affected both height and survival. Dynamic programming analysis-using both soil expectation (Se)...
Growing societal demand for forest products is pressuring managers to increase productivity from a finite land area, and it is expected that increased supply will come mostly from expansion of intensively managed stands. The USDA Forest Service and numerous collaborators created the Long-Term Soil Productivity (LTSP) network of research sites...