The structure of two oak woodland types in the Santa Rosa region
of the Santa Ana Mountains of southern California has been described
by Zuill (1967). One type called the grass oak woodland (GOW) is
composed mainly of Q. engelmannii on hills and slopes. The other
type called the dense...
Over the last 150 years, Oregon white oak habitat in the Willamette Valley has been converted to support grass crops, orchards and vineyards, cities, and conifer forests, nearly extirpating it from the Willamette Valley. Yet Oregon white oak offers many ecosystem services to the Willamette Valley and its residents. Recent...
The primary purpose of this Guide is to encourage private landowners to conserve, and when appropriate, actively manage Oregon white oaks that already exist on their property, and consider planting additional oaks. In the early chapters of the Guide, we describe some of the uses and benefits of this remarkable...
Intelligent selection of wood for the job it is to do is particularly essential during wartime conditions of scarcity when supplies must be conserved and useful life extended. One way of increasing the service life of wood exposed to damp conditions is to select material that has a high natural...
Published February 1939. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
I evaluated the response of the federally listed endangered plant species Bradshaw's desert parsley (Lomatium bradshawii) to livestock grazing and small mammal depredation at Oak Creek, Linn County, Oregon, 1997-1998. I established six study blocks (three each in wooded and herbaceous pastures) with plots in each block randomly assigned to...
The incipient motion of sediment particles in gravel-bed
rivers is a very important process. It represents the
difference between bed stability and bed mobility. A field
study was conducted in Oak Creek, Oregon to investigate
incipient motion of individual particles in gravel-bed
streams. Investigation was also made of the incipient...
Oregon white oak, Quercus garryana Dougl., could have greater commercial use, but information on its drying properties is lacking. All oaks are difficult to dry, and the initial kiln conditions are important to prevent excessive surface checking and honeycombing. This study illustrated that a maximum dry-bulb temperature of 110 F...
Pre-flood (1995), and post-flood (1996) channel stability surveys were conducted on 22 reaches along Oak Creek, Benton County, Oregon in an effort to note if the flood of February 1996 altered the channel and if the channel stability survey that was being used accurately predicted the channels resistance to change...
Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or...
Metal and hydrogen ion acidity and extreme nitrate concentrations typical of
Department of Energy (DOE) legacy waste sites pose formidable challenges to
successful implementation of in situ bio-immobilization. Intermediate-scale (~ 2.5 m),
flow through models of an in situ bio-barrier were constructed to investigate U and Tc
removal from groundwater...
This research was conducted in the Mamora National Forest of
Morocco to: (1) Evaluate the effect of cork oak (Quercus suber L.)
crown cover on seasonal herbage production, nutritive quality, and
foliar cover on two distinctive sites in each of two years (1982,
1983) and to (2) assess the effects...
Previous research has indicated that considerable amounts of finely divided slash accumulate in small mountain streams following timber harvesting. The subsequent biological decomposition of this organic matter can result i.n the reduction of dissolved oxygen (DO) concentration to levels as low as 0.6 ppm. These DO levels are lethal
to...
Unpaved roads are sources of chronic sediment in forested watersheds. Bare soil on roads is exposed to erosion from rainfall and runoff Published research on sediment production from forest roads focuses primarily on road characteristics. Since water drives the mechanics of sediment transport, hydrologic variables should correlate with sediment production....
The variable oak leaf caterpillar, Heterocampa manteo (Dbldy.), has defoliated hardwoods in two North Dakota locations for 3 years (Fig. 1). This is the second consecutive year its damage has been monitored. Monitoring has been done cooperatively with William Brandvik, Associate
State Entomologist, North Dakota Department of Agriculture.
Grain-size distributions of gravels transported as bedload in Oak Creek, Oregon,
show systematic variations with changing flow discharges. At low discharges the gravel
distributions are nearly symmetrical and Gaussian. As discharges increase, the
distributions become more skewed and follow the ideal Rosin distribution. The patterns of
variations are established by...
Gathering empirical data on the factors and processes affecting bedload transport
in the field is difficult. This project conducted during the winter of 1996 field tested a new passive method of positively tracking individual particle movement. The project was conducted in Oak Creek, a gravel bedded stream, located in Corvallis,...
The impact of forest roads on the hydrology of forested watersheds has long been studied. While forest roads have been reported to alter storm runoff at the road segment scale, the potential for changes to be detectable at the small watershed scale has been debated. The purpose of this study...
Sudden Oak Death is the common name for a disease caused by Phytophthora ramorum, a previously unknown and recently introduced non-native pathogen.
• Phytophthora ramorum has killed hundreds of thousands of oak and tanoak trees in 14 coastal counties in California and hundreds of tanoak trees in Curry County, Oregon....
Sudden Oak Death (SOD) is a plant disease caused by the water
mold Phytophthora ramorum. This organism causes disease in
more than 100 species of trees, shrubs, herbs, and ferns.
Humboldt Redwoods State Park in southern Humboldt County, California is a coastal redwood forest, a highly unique and valued ecosystem. It has many social, cultural, ecological, and economic values, including recreational benefits, heritage and aesthetic values, high biodiversity, nutrient cycling, and climate regulation. However, Humboldt County is at risk of...
Alerts people who visit, live, or work in certain areas of Oregon and California about a serious plant disease called Sudden Oak Death, and asks them to take steps to prevent spreading the disease. Gives action steps, shows disease symptoms on various host plants, and gives numerous sources for more...
Alerts people who visit, live, or work in certain areas of California and Oregon about a serious plant disease called Sudden Oak Death, and asks them to take steps to prevent spreading the disease. Gives action steps, shows disease symptoms on various host plants, and gives numerous sources for more...
This study was to investigate effects of growth rate
and cambial age on properties of wood from two increasingly
used hardwood species, red alder (Alnus rubra Bong.) and
Oregon white oak (Quercus garryana Dougl.), for better
understanding factors affecting wood quality in hardwoods.
Thirty 7-year-old trees grown at widely varying...
Poison oak is common in western Oregon and Washington. Its near relative, poison ivy, is found in eastern Oregon and Washington, throughout Idaho, and eastward. Both plants are native to the Pacific Northwest.
Published November 2009. A more recent revision exists. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The importance of active-entry drift at a community-scale
was evaluated by testing whether the placement of wood
in streams affected the abundance of Baetis spp. mayflies in
drift. Baetis were chosen because they use drift as a
behavioral strategy and are important in salmonid diets. The
density of woody debris...
This work furthers the understanding of processes occurring in catchments that affect stream nitrate concentrations using two different approaches: a temporally intensive case study of three headwater catchments with varying land use (through storm event monitoring) and a spatially intensive study on the regional scale (through statistical modeling) of 1st-4th...
The management of existing forest road systems is an issue of growing importance and public debate. Roads can alter the hydrologic processes in a watershed especially at stream crossing culverts where road ditches channel runoff directly into the stream. The objective of this study was to determine how surface runoff...
Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks are likely insufficient for long-term conservation of native biodiversity, has necessitated that agricultural systems contribute to conservation of native...
The spatial and temporal variability of sediment transport processes in Oak Creek, OR was investigated and used to explore two study questions: 1) How do sediment transport processes influence benthic algal communities?, and 2) Can fluvial-hydraulic models make accurate predictions of bed load transport rates? Our study was conducted in...
The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...
Suspended sediment and in situ turbidity data from two western Oregon streams, Oak Creek and South Fork Hinkle Creek, were used to estimate annual sediment loads for the 2006 water year (October 1, 2005 to September 30, 2006). Water samples and in situ turbidity observations were taken following the Turbidity...
The goal of this study was to advance methods for assessment of forest road hydrologic
response and sediment yield at a catchment scale. This research looked at the effect of
soil depth estimation on the Distributive Hydrology Soil Vegetation Model (DHSVM),
assessed the uncertainty and accuracy of hydrologic modeling of...
Phytophthora ramorum is a plant pathogen that was accidentally introduced to the United States. This invasive microorganism has killed over a million trees in California and Oregon, and continues to spread to new areas. Diseased areas have been nationally quarantined to prevent further spread and more than ninety countries include...
This study was made to present any evidence as to differences
in the frequency of occurrence of corticolous lichens from east to
west in the Willamette Valley on a bark substrate of Quercus Garryana.
Twenty-four species of lichens were observed to be present
within the grid area of the 100...
The sudden oak death pathogen, Phytophthora ramorum, is present in southwestern Oregon, and while an eradication effort is underway, the potential impact of the polyphagous pathogen on surrounding vegetation is unknown. Plant communities in the area are substantially different from those affected in California, although tanoak (Lithocarpus densiflorus), evergreen huckleberry...
Colonization of N. densiflorus tissues by P. ramorum is not well understood. The pathogen is able to colonize nearly all tissues of this host but it is unclear how a tree is ultimately killed. Because this is such a destructive invasive pathogen, it is important to investigate its pathogenic strategy....
Tanoak (Lithocarpus densiflorus), along with some other members of Fagaceae, are susceptible to sudden oak death caused by the oomycete Phytophthora ramorum. Symptoms of the disease include dying crowns, bleeding cankers, and eventually death of infected trees. The cause of mortality is not well understood, but recent research indicates that...
Quercus garryana dominated plant communities are found in
the interior coastal valleys and on foothills from southeastern
Vancouver Island, British Columbia, south to San Francisco,
California. They occur as savannas, intermixed with a variety of
conifers, and in almost pure stands. The diversity of habitats
occupied by the species and...
Phytophthora ramorum, an oomycete plant pathogen, is the causal agent of sudden oak death, a serious disease of Fagaceous trees in California and Oregon over the last decade. Tanoak (Notholithocarpus densiflorus) is one of the most susceptible host species, but the cause of host mortality is poorly understood. Previous research...
In response to concerns about excessive stand densities and high-severity wildfires, land managers in the western United States are carrying out extensive programs of fuel reduction thinning. How will these sudden reductions in canopy cover and associated changes in habitat affect native and exotic herbaceous vegetation and canopy species regeneration?...
In the United States, many of the thorniest natural resource conflicts occur on private lands. This is especially true in the Willamette Valley of Western Oregon where the hallmark habitat type, Oregon white oak woodland and savanna, is imperiled. Almost exclusively found on private land, Oregon white oak is threatened...
This research analyzes how family forest owners conceptualize biodiversity in one high-conservation value area of oak woodland in the Willamette Valley of Western Oregon. Oregon white oak (Quercus garyanna) woodland, one of the most biologically diverse ecotypes in the state of Oregon, is in decline. Much of the oak ecotype...
Quarantines and control programs are two policy tools used to prevent and reduce the damages caused by invasive species. Quarantines restrict the movement of material that could spread invasive species. Their requirements impose costs on businesses within the quarantine zone by creating barriers to trade and increasing production costs, which...
Previous studies of bird communities in the mid-Willamette Valley, Oregon, indicated that Oregon white oak (Ouercus garryana) stands supported more cavity-using bird
species than sympatric stands of Douglas-fir (Pseudotsuga menziesii). Mature Oregon oak stands are being harvested and few are regenerating. I compared cavity availability for hole-using fauna among 10...
Research on the population genetics of microbial organisms requires the use of specialized analyses designed for clonal organisms to avoid violating the assumptions of traditional population genetic models. The tools necessary for performing these analyses existed as a set of unrelated software with non-overlapping capabilities and did not cover all...
In the last 200 years there have been significant declines in the amount and structural complexity of oak-dominated forests and savannahs in the Pacific Northwest. Restoring oak systems often involves selectively thinning stands of oaks in order to reduce competition for sunlight. In choosing which trees to cut, land managers...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...