This study assessed growth, condition, and mortality of residual trees one decade after harvest across three silvicultural treatments in thirty 85- to 125-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Oregon Coast Range foothills. Group-selection cuts had 33% of the entire stand volume extracted as patches approximately 0.2–0.8 ha...
A seasonal hair-loss syndrome of native deer began to occur in the Pacific Northwest United States in the mid-1990s. Clinical manifestations of the disease typically include large numbers of chewing lice on Columbia Black-tailed deer (Odocoileus hemionus columbianus) and Columbia White-tailed deer (Odocoileus virginianus leucurus). Expenditure of energy responding to...
Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i) estimate the...
We analyzed 45 years of data collected from three ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) levels-of-growing-stock installations in Oregon (OR) and northern California (CA), USA, to determine the effect of stand density regimes on stand productivity and mortality. We found that periodic annual increment (PAI)...
Ponderosa pine is an important species both commercially and ecologically in western North America. This study considers the incidence of insect and disease pests on a series of replicated ponderosa pine research plantations in northern California. The studies, on an environmental gradient, contain a series of silvicultural treatments including vegetation...
For nearly two decades, foresters in the Oregon Coast Range have been witnessing a substantial decease in Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco.) vigor and growth, caused by Swiss needle cast (Phaeocryptopus gaeumannii). Currently, no solutions are in sight but aerially-applied sulfur may alleviate Swiss needle cast and its...
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....
Studies of nutrient limitation in Douglas-fir forests of the Pacific Northwest focus predominantly on nitrogen, yet many stands demonstrate negligible or even negative growth response to nitrogen fertilization. To understand what nutrients other than nitrogen may limit forest productivity in this region, we tested six fertilizer treatments for their ability...
Calcium (Ca) is an essential macronutrient that is increasingly recognized as a biogeochemical factor that influences ecosystem structure and function. Progress in understanding the sustainability of ecosystem Ca supply has been hampered by a lack of information on the various forms and pools of Ca in forest ecosystems. In particular,...
Nutrient limitation constrains tree growth in many managed forests. Nitrogen (N) is the most common limiting nutrient, but high N supply can shift limitation to other nutrients, particularly phosphorus (P) and the base cations calcium (Ca), magnesium (Mg), and potassium (K). As different soil minerals have different capacities to supply...
The College of Forestry Integrated Research Project (CFIRP) is an on-going experiment in the eastern Coast Range foothills of western Oregon. Started in 1989, a team of scientists, resource managers, and students at Oregon State University designed and implemented silvicultural alternatives to clearcutting. These silvicultural practices aimed to create and...
Forest vegetation management (FVM) is an important component of reforestation in the Pacific Northwest (PNW). Several studies have demonstrated the benefits of vegetation management on planted conifer growth and survival. However, few reports have been published on the long-term effects of FVM treatments on total ecosystem biomass accumulation and aboveground...
Adiabatic parcel models suggest specific relationships between cloud thickness and cloud properties. Such relationships govern cloud radiative forcing and thus cloud feedbacks in the climate system. Current remote sensing techniques work well at measuring these properties in low-level cloud systems that are overcast. Significant biases exist, however, when measuring cloud...
The importance of accurately identifying inventories of domestic energy, including forest biomass, has increasingly become a priority of the US government and its citizens as the cost of fossil fuels has risen. It is useful to identify which of these resources can be processed and transported at the lowest cost...
Pacific Coast band-tailed pigeons (Columba fasciata) have declined markedly
during the past several decades. Despite implementation of increasingly restrictive
hunting regulations, populations have shown minimal signs of recovery. I radio-marked
127 adult band-tailed pigeons in the central Oregon Coast Range in April-May of 1993-95
to document nesting chronology and productivity,...
Animal weapons are thought to have evolved to compete for reproductive opportunities within a species. Across the diverse weapon-bearing taxa, several evolutionary trends have emerged: (1) increasing complexity and relative size across ontogeny, (2) sexual dimorphism, and (3) higher levels of random deviations from symmetry (i.e., fluctuating asymmetry) than non-weaponized...
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...