Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. Growth and wood density traits of individual rings were measured via X-ray densitometry, and relationships of ring density and its...
We evaluated effects of chemical fertilizer, spacing, and interplanted nitrogen-fixing trees on wood density and diameter growth of 15-year-old Eucalyptus saligna trees. The trees were grown in silvicultural trials established on former sugarcane land on the island of Hawaii. Elevation was 480 m, slopes were gentle, and annual rainfall averaged...
The Willamette Valley (WV) race of ponderosa pine (Pinus ponderosa) is being widely planted for timber in the Willamette Valley, western Oregon, because it grows in habitats that are either too wet or too dry for Douglas-fir (Pseudotsuga menziesii). Compared to the eastern Cascade Mountains (CM), the WV has 3...
Like most ecological communities, aspen (Populus tremuloides) forests are influenced by a synergy of bottom-up (resources-driven) and top-down (predator-driven) processes. Since the 1920s, ecologists have observed the decline of many aspen communities throughout the Intermountain West. The extent and possible drivers of this decline are topics of much recent scientific...
To learn the effect of wind on a species native to a windy site, I compared germination, seedling survival, seedling form, and the force required to uproot seedlings in a wind-exposed and a wind-sheltered site. In February 1992, the sand dune perennial Lupinus arboreus Sims. was planted in wind-exposed and...
Herein, we posit a link between the ecological extinction of wolves in the American West
and the expansion in distribution, increased abundance, and inflated ecological influence
of coyotes. We investigate the hypothesis that the release of this mesopredator from wolf
suppression across much of the American West is affecting, via...
To guide the future development of CO₂-atmospheric inversion modeling systems, we analyzed the errors arising from prior information about terrestrial ecosystem fluxes. We compared the surface fluxes calculated by a process-based terrestrial ecosystem model with daily averages of CO₂ flux measurements at 156 sites across the world in the FLUXNET...
Recent natural disasters around the world including
both tsunamis and hurricanes, have highlighted the inability
of wood buildings to withstand wave and surge
loading during these extreme events. Little is known
about the interaction between coastal residential light-frame
wood buildings and wave and surge loading because
often little is left...
Wood-plastic composites are generally presumed to be inherently more resistant to moisture uptake than solid wood, but there is little data on the relative rates of moisture uptake in these materials over time. Trex[R] and Strandex[R] deck sections were immersed in water for up to 215 days, then sections were...
This article examines visitor perceptions of voluntary environmental programs (VEPs) at the Mt. Bachelor ski area in Oregon, USA by examining what they know about VEPs, how these programs influence motivations to visit this area currently and in the future, and how place attachment, value orientations, and specialization influence these...
Six 40-year-old red alders (Alnus rubra Bong.) were harvested from a mixed stand of A. rubra and big-leaf maple (Acer macrophyllum Pursh) in the Oregon Coast Range to evaluate variation in their wood characteristics at two heights. Because the trees had a slight lean (4 to 14°), we sampled along...
The emergence of a new generation of remote sensing and geopositioning technologies, as well as increased capabilities in image processing, computing, and inferential techniques, have enabled the development and implementation of increasingly efficient and cost-effective multilevel sampling designs for forest inventory. In this paper, we (i) describe the conceptual basis...
Lidar is currently the most accurate method for remote estimation of forest structure, but it has limited spatial and temporal coverage. Conversely, Landsat data are more widely available, but exhibit a weaker relationship with structure under medium to high leaf area conditions. One potentially valuable means of enhancing the relationship...
Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool for estimating the biomass resources available to support bioenergy production in rural communities of interior Alaska. In this study, we present a methodology for estimating forest biomass over a 201,226-ha area (of which 163,913...
Large quantities of smaller diameter materials are available in the overstocked forests of eastern Oregon and Washington, but the costs of removing these materials and the long distances from markets sharply reduce the potential of this resource. Failure to thin these forests will sharply increase the likelihood of catastrophic wildfires....
In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had...
Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m-2 d-1) is 10–30 times higher than a level supported solely by the input...
Retreating glaciers and the periglacial areas they vacate for organismal colonization produce a harsh environment of extreme radiation, nutrient limitations, and temperature oscillations. They provide a model system for studying mechanisms that drive establishment and early assembly of communities. Here, we synthesize more than twenty years of research at the...
The high decay resistance of western redcedar (Thuja plicata Donn) is due to the presence of toxic extractives, called tropolones, in the heartwood. Therefore, tropolone content may be used as an indicator of decay resistance. With increment core-sized samples of western redcedar heartwood, we used gas chromatography to measure tropolone...