This study was undertaken to evaluate the usefulness of sediment records for correlating changes in the sediment characteristics of four Oregon lakes with past cultural developments of the lakes and their watersheds. The lakes chosen for this study were Waldo, Odell, and
Diamond lakes located in the Cascade mountains and...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB...
This research examines the downstream fining phenomenon as it operates in coastal gravel-bed rivers of Oregon. Downstream fining is a change in bed composition toward smaller sediment sizes in the downstream direction. Changes in stream flow discharge and channel slope affect the rate of bed-load transport, thereby altering the downstream...
Fifty-two one-meter plankton net samples from four stations off Newport, Oregon, were examined for composition and abundance of euphausiids and copepods. They provided data on dominance, species associations and environmental relationships. The euphausiid-copepod population off Oregon is composed of 12 numerically dominant species. These species occurred in most of the...
Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has...
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...
The following report presents a summary of the work conducted between
1 March 1973 and 31 December 1973 as proposed in our research contract "The
Development of Methods for Studying Physical and Biological Processes in
the Nearshore Zone on the Pacific Coast of the United States," supported by
the Eugene...
New approaches are needed to quantify and understand spatial patterns of stream fishes and their environment. Concepts in riverine ecology emphasize the importance of thermal zones and gradual longitudinal changes in physical habitat and biota, but little is known about spatial variability within the river continuum. I present a conceptual...
Upper Klamath Lake in south central Oregon annually experiences intense
blooms of cyanobacteria, primarily Aphanizomenon flos-aquae. Domination of the
lake phytoplankton community by this single species regularly results in drastic
changes to water quality. Photosynthetic activity of such extensive populations can
result in pH over 10. Blooms typically expire in...