Effect of a sudangrass green manure in two soil types on the activity, populations
and community structure of soil microorganisms, populations of Verticillium dahliae in
soil and on potato roots, and potato early dying, were evaluated in a field microplot
experiment in the Columbia Basin. Potato cv. Russet Burbank was...
Landslides are frequent in the steep forested regions of the Oregon
and Washington coastal mountain ranges. The need for forest products
has resulted in increasing logging activity in these marginally stable
areas. The occurrence of landslides has increased, which in turn has
focused greater interest in slope stability management.
Of...
The morphology, genesis, and classification of soils
forming in multiple tephra deposits of recent age from
Mt. St. Helens volcano in southwestern Washington Cascade
Mountains was studied.
Soils which occupied well drained and poorly drained
positions on the landscape were characterized according
to their morphology and the results of analyses...
Intensive cultivation of Walla Walla silt loams (coarse silty,
mixed, mesic, typic Haploxeroll) in eastern Oregon and Washington
during the past 50 years, has decreased internal soil drainage in
the 15 to 40 cm layer. However, no measurements have been made to
determine the causes and corrective management for this...
This study evaluated the effect of soil compaction on the growth
of natural regeneration on volcanic ash-influenced soils in the
southern Washington Cascades. Growth of 9 to 18 year-old sapling-.
sized Ponderosa pine (Pinus ponderosa Laws.) was studied on sites
ranging from 915 to 1006 m elevation in an area...
Soil acidification sometimes is necessary for optimum plant growth
west of the Cascade Mountain Range. Commercial producers of
blueberries, azaleas, rhododendrons, and other ornamentals may
need to reduce soil pH for optimum production.
Soil acidification is best performed prior to planting; it is much
more difficult in established plantings. No...
Plant succession is among the fundamental concepts in ecology. Studies addressing plant recruitment, successional mechanisms, and the role of root-colonizing fungi with focus on dark-septate endophytes (DSE) were
conducted in the laboratory and on the forefront of receding Lyman Glacier (North Cascade Range, Washington, U.S.A.). Primary successional studies primarily focus...
With rising concentrations of CO₂ in the Earth's atmosphere causing
concern about climate change, many solutions are being presented to
decrease emissions. One of the proposed solutions is to sequester excess
CO₂ in geological formations such as basalt. The deep subsurface is known
to harbor much of the microbial biomass...
Rhododendrons and blueberries are popular
plants in home gardens in western Oregon and
Washington. Both are easy to grow in most
gardens, but problems with growth can occur if
the soil is not sufficiently acidic. Even in the
naturally acidic soil west of the Cascade Mountains,
soil often is not...
Soil organic carbon (SOC, kg C m-2) is an important component in evaluating global C stores. The nitrogen (TN, kg N m"2) cycle is closely linked to C and understanding its role is also important. Contents and distributions of SOC and TN in soil profiles, to 1-meter depth, were estimated...
Data on soil temperature at two locations and five depths, tensiometer readings, and soil moisture release curves for the soils of Findley Lake are presented in this report.
When precipitation falls on frozen soil, serious soil loss can
occur. In order to assign realistic probabilities to the occurrence of
this condition for use in predicting erosion rates over long time
periods, a technique for combining characteristics of precipitation and
air temperature records is applied to hourly wet season...
The occurrence of frozen soil has a major effect on runoff and soil loss
in the Pacific Northwest. Hence, information regarding the probabilities of
occurrence of periods during which the soil may be frozen is necessary in order
to adequately forecast long-term erosion rates for this region. In order to...
Periods of precipitation with certain combinations of characteristics
(e.g., high intensity rainfall on saturated soil) can lead to appreciable
soil loss in the Pacific Northwest. In order to assign realistic probabilities
to the occurrence of these periods for use in predicting long-term
erosion rates, a soil erosion-specific definition of a...
Forest harvest can have significant impacts on forest ecosystems that may influence the capacity of soils to sequester carbon (C). The microbial community controls decomposition, which is a critical process in partitioning litter- and root-C between CO₂ and storage in semi-permanent soil-C pools. The objectives of this study were to...
Understanding the transport and retention of radionuclides in the environment is important for protecting freshwater supplies and minimizing impact to biologic systems. Technetium-99 (Tc⁹⁹) is a radionuclide of interest due to its long half-life (2.13 x 10⁵ years) and toxicity. In the form of pertechnetate (TcO₄⁻), Tc is expected to...
Nutrient management plans for crops require estimates of plant-available nitrogen (PAN) provided by application of manure or compost. Recent developments have stimulated interest in utilizing manure nitrogen (N) as a resource. These factors include the following:
• Increased cost of N fertilizers
• Increased value of PAN from manure on...
Dry coniferous forests in the western United States are experiencing severe wildfires, insect outbreaks, forest disease epidemics and a growing presence of invasive species. Policies strongly emphasize reducing hazardous fuels at the Wildland Urban Interface (WUI) where communities and forests intersect. However, these areas present restoration challenges as they tend...
Findley Lake watershed is located in the Snoqualmie National Forest and has a surface area of 259 ha (1 Mi²). The lake is at an elevation of 1128 m (3701 ft) but the ridges attain elevations of 1450 m (4750 ft).
The Cougar Mountain Formation, consisting of lava flows, conglomerate,...
Distribution of Vibrio parahaemolyticus in Oregon and Washington oystergrowing areas was studied between November 2002 and October 2003. V. parahaemolyticus was detected in 14.3% of oyster, 23.0% of seawater, and 44.4% of sediment samples with very low levels (≤7.4 MPN/g) of pathogenic strains being detected in oysters. Occurrence of V....
This is the annual report from the investigators responsible for soil
characterization at the Findley Lake watershed. Soil characterization
is complete for two soils and is in progress on six others. Site
preparation for years 3 and 4 is complete except for lysimeter
installation.
Concentration ratios are used to determine the transfer of nuclides from soil to biota to fauna. Some nuclides have limited associated data though, this has not prevented predictions from being performed at sites without associated data. These ratios are site specific and are not fully applicable when applied to other...
This publication assists western Oregon farmers and agricultural professionals in determining the nitrogen fertilizer replacement value of winter cover crops. Includes information on plant-available nitrogen (PAN) basics; a site-specific, step-by-step method to estimate PAN; Willamette Valley case studies; and appendices summarizing Willamette Valley cover crop research that supports these PAN...
Shovel logging is a relatively new ground-based method of yarding tinther. It involves moving logs from stump to landing by successive swinging with a hydraulic excavator modified into a log loader by replacing the shovel bucket with a grapple. Loaders used in shovel yarding can weigh in excess of 100,000...
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...
Recreational impacts on the subalpine-alpine ecosystems of Mount Rainier National
Park have developed over the past century, and today pose a major problem for park
managers. Field data were collected during the summer of 1987 in the Paradise meadows
area in order to describe visitor impacts on social trails (trails...