The eruption of Mt. St. Helens provided the
opportunity to study secondary production of grazing insects in the context of disturbance. Two stream sites were chosen that significantly differed in how their
watersheds were impacted by the eruption. Clearwater Creek was catastrophically disturbed (physical alteration of habitat, loss of riparian...
Capillary pressure-saturation data obtained for unconsolidated porous media with different liquids are examined to investigate the effects of clay-liquid interactions on liquid retention. Liquid retention functions are assumed to reflect the effective pore-size distributions. The hydraulic variables, capillary pressure and saturation, are transformed to account for changes in liquid retention...
The biochemical degradation of domestic sludge deposits exposed to benthic marine conditions was investigated using a laboratory Deep Sea Simulator. The rate and extent of deposit stabilization were determined for select hydrostatic pressures and hydrogen acceptor conditions by monitoring depletion of particulate organic carbon in 2.0 and 3.0 centimeter deposits....
As part of a hierarchical approach to classifying watersheds and stream habitats based on geomorphic and geologic criteria, we defined ten classes of fluvial and lacustrine habitats at the scale of valley segments. Valley segments are landscape units which encompass surface waters and the adjacent floodplains and hillslopes with which...
Sources of polar/water-soluble organic compounds conjunctly with apolar biomarkers were characterized in natural organic matter. This multi-biomarker approach was accomplished by a simple analytical method consisting of extraction with dichloromethane:methanol (2:1, v/v), silylation and analysis by gaschromatography- mass spectrometry (GC-MS). Polar and apolar biomarkers, derived mainly from higher plants and...
The indiscriminate release of fecal bacteria to the environment
can present a public health hazard when pathogenic species gain access
to drinking and recreational water sources. The extent of bacterial
contamination of surface and ground waters associated with animal
production units and waste application areas seems largely dependent
on the...
Soil erosion by mass wasting is the major problem on forest
lands of the Pacific Northwest, The clay fractions of soils from a
large number of sites in Oregon's Western Cascades were characterized
in order to determine the relationships of various clay materials to
mass movements. Each site was either...
Clay mineral genesis was studied in soils representative of several
different geomorphic surfaces in western Oregon, ranging in age from
Pliocene-early Pleistocene to late Pleistocene. Soil solution studies,
clay mineralogy, and soil raicromorphology were employed to provide
evidence of clay mineral synthesis and interpret soil genesis.
Soils at each study...
This study consisted of two research projects in the Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh) alliance, the most extensive of the big sagebrush complex in the Intermountain West. In the first project, we intensively sampled 107 relatively undisturbed, late seral Wyoming big sagebrush...
Two strategic approaches to water quality control in Oregon's
Willamette River are presently being utilized: point source treatment
and flow augmentation. Dry weather releases from reservoirs are for
authorized purposes other than water quality. Reservoirs can participate
in pollution control by summer flow augmentation where authorized water
resource objectives (flood...