Forests are important to Oregon for their beauty as well as economic value, and Douglas fir trees are among the most common and important in the state. Managing and monitoring Oregon’s forests is imperative to ensure they can remain healthy and productive. One tool that helps forest scientists to understand...
An increase in frequency and severity of hot, dry summers has been associated with a dramatic shift in the coniferous forests of western Oregon’s valleys, especially on the privately-owned properties along the low-elevation edges of these valleys. Various conifer species, including Douglas-fir (Pseudotsuga menziesii), are declining in these forests, leaving...
Forest harvesting practices can expose mineral soils, decrease infiltration capacities of soils, disturb the stream bank and channel, and increase erosion and fine sediment supply to stream channels. To reduce nonpoint source sediment pollution associated with forest management activities and to maintain the high water quality typically provided from forests,...
For the sample of wide-ringed Douglas-fir discussed in this report, the relationship between specific gravity and percentage of summerwood is linear over a range of 16 to 60 percent summerwood content of the annual ring. The specific gravity of the summerwood and springwood portions of 96 dissected annual rings is...
This dataset consists of planted crop-tree growth metrics (Pseudotsuga menziesii), non-crop tree vegetation metrics, and foraging data for black-tailed deer (Odocoileus hemionus columbianus) and Roosevelt elk (Cervus canadensis rooseveli) collected from the Intensive Forest Management experiment, Oregon Coast Range, USA, 2011-2016. The objective of the experiment was to quantify the...
Estimating volume gains in genetically improved stands at rotation age is challenging because first-generation progeny tests in Douglas-fir were typically established to measure the relative growth performance of individual trees from open-pollinated parent trees. The overall goal of this dissertation research was to improve growth simulation of genetically improved Douglas-fir...
This work combines both applied and basic research regarding previously undescribed relationships between two ecologically and economically important insect groups in coniferous forests, bark beetles (Coleoptera: Curculionidae, Scolytinae) and wild bee (Hymenoptera: Apiformes) communities in Western North America. Across the continent, native bark beetle outbreaks are key drivers of structural...
In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
There is a lack of fundamental knowledge about the role which adhesive flow and infiltration plays in the micro-mechanical performance of wood adhesive bonds. This data set, for the first time, provides a way to study directly the relationship between adhesive flow and the micro-mechanics of wood adhesive bonds.
Specimens...
Stem form development of trees in response to wind has been established in the literature to be a response to stem sway induced by the wind. The response is manifested in modifications to height and diameter growth which strengthen the stem against wind stresses. Experiments in the literature show that...
This paper describes a study done on swinging and processing whole tree, tree length and log length pieces in a smallwood Douglas-fir thinning. Two machines were evaluated, a 70 horsepower rubber tired skidder and a hydraulic loader mounted on a 6 x 4 live tandem truck.
The study took place...
The comercial thinning of second-growth stands in the Pacific Northwest is becoming increasingly important for satisfying the demand for timber. Cable logging will require the rigging of smaller intermediate support trees rather than those utilized on old-growth timber sales. This paper reports on the results of a study designed to...
A method is described to determine the distribution of the bending stresses in a wood beam when some of these stresses exceed the proportional limit. This is used to calculate the position of the neutral axis and the bending strength of some Douglas-fir beams. The calculated values agreed with the...
Forest soils and topography have long been known to influence forest productivity in complex terrain such as Oregon’s Coast Ranges. Incorporating physical site characteristics into predictions of forest growth and yield, however, has been problematic because of the high spatial variability of soil properties and the challenges associated with representing...
Drought is expected to increase in many parts of the world and has been shown to affect tree physiology and growth, with seedlings being particularly vulnerable. Seedling drought responses are often species dependent, and even within species different populations may demonstrate a spectrum of responses to drought, from susceptibility to...
Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
It is uncertain how predicted changes in climate will impact vegetation responses and plant species’ distributions because the physiological mechanisms underlying thresholds for damage are not well understood, and responses to stress vary by functional type and developmental stage. Thus, it is crucial to investigate physiological responses to heat and...
Policy regarding the management of public forests has undergone a drastic shift over the past couple of decades due to the loss old-growth forests in the Pacific Northwest (PNW) of the United States. For much of the 20th century, forest management on public lands emphasized timber production through the use...
Wood density is controlled to a large extent by the relative widths of earlywood and latewood in the stem, but the mechanisms controlling these amounts are poorly understood in coastal Douglas-fir. To understand the role of climatic factors, one hundred and thirty-six increment cores were collected and measured from the...