The Steamboat Creek basin drains 227 mi² (588 km²) of steep forested terrain into the North Umpqua River of Southwest Oregon, 39
mi (63 km) northeast of Roseburg. Summer base flows for Steamboat Creek average 83 cfs (2.35 m³/sec). Steamboat Creek and its
tributaries are considered important to the production...
Snorkel dive estimates and an inventory of stream habitat of the juvenile steelhead (Oncorhynchus mykiss) population in the Steamboat Creek basin were made in the summers of 1987 and 1988. Emigration was
monitored by fish trapping from spring through fall of 1988. Distribution, abundance, and habitat utilization of juvenile steelhead...
The restoration of rivers and streams should be based on a
strong conceptual framework. Streams are developing systems. As
such, streams exhibit temporal behaviors that change with changing
stream environments. Underlying the dynamic development of streams is
potential capacity. Streams express this capacity as an array of
habitats over time...
Several types of instream structures were evaluated for their
potential to provide rearing habitat and to increase reach carrying
capacity for steelhead trout (Salmo gairdneri). Evaluation was
conducted in each season over the course of 1 year.
Blast pools created in bedrock glides increased the carrying
capacity of stream reaches...
This research investigates the direct and downstream impacts of clearcut harvest units on stream temperature as a part of the Hinkle Creek Paired Watershed Study. The Hinkle Creek watershed is located in the foothills of the Cascade Mountains about 30 kilometers northeast of Roseburg, Oregon, is privately owned, and supports...
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...
Stream temperature is a water quality parameter that directly influences
the quality of aquatic habitat, particularly for cold-water species such as Pacific
salmonids. Forest harvesting adjacent to a stream can increase the amount of
solar radiation the stream receives, which can elevate stream temperatures
and impair aquatic habitat. Oregon Forest...
The increased demand for wood and fiber from a continually shrinking land base has resulted in the use of intensively managed forest plantations. The concentration of timber production on the most suitable sites allows the world's demand for forest products to be met on less land and enable native forests...
The effects of beaver (Castor canadensis) on stream morphology, riparian zones, and coho salmon (Oncorhynchus kisutch) fry in Cape and Cummins Creeks, Oregon, were examined using stream surveys, vegetation transects, and coho salmon fry counts in 1987. The basin around Cape Creek has been extensively logged since the late 1940's....
Western juniper (Juniperus occidentalis) encroachment has been associated with increased soil loss and reduced infiltration resulting in the loss of native herbaceous plant communities and the bird and animal species that rely on them. Hydrologically, however, change in water yield has been linked with the amount of annual precipitation a...
Knowledge about vegetation patterns and ecological processes in unmanaged, late-successional
watersheds is needed to provide a foundation for forest management strategies
aimed at conserving native biodiversity. I examined influences of environmental variability
and disturbance history on forest structure and composition in the Cummins Creek
Wilderness, located on the central Oregon...
The purpose of this study was to evaluate the impact sediment has on the survival of
bacteria in a typical rangeland stream. This information is an important component in
determining a time integrated prediction of bacterial numbers in the stream sediment and
overlying water. Bacterial survival in stream is a...
This study explored how selected input and redistribution processes affect the amount and arrangement of in-stream wood within the 64 km2 Lookout Creek watershed in the Andrews Forest, western Cascade Range, Oregon. A longitudinal inventory of in-stream wood was conducted over approximately 20 km of stream length in 2nd to...
Research was conducted in the Oregon Coast Range to address
the concern that conversion of large diameter old-growth forests
to small diameter second-growth forests would lead to reduction
of large woody debris in adjacent stream channels. The objective
of the study was to quantify spatial trends in large woody debris...
The primary goal of this research project is to quantitatively measure the temporal scales of hyporheic exchange along a stream network. Our goal is to examine how hyporheic exchange varies with increasing stream size. Many previous studies focus on single stream reaches or on several reaches of similar sized streams,...
Initially, components of an aquatic food web were examined to study impacts of recreational use on the aquatic ecology of Quartzville Creek, Oregon in 1995 and 1996. Measurements of the food web components consisted of observations of harlequin ducks (Histrionicus histrionicus), visual counts of the larval caddisfly Dicosmoecus gilvipes, benthic...
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...
We evaluated the effects of herbage removal from livestock grazing on Oregon spotted frog (Rana pretiosa) habitat use by monitoring frog locations in grazed and matched ungrazed treatments across a range of grazing intensities at Jack Creek, Fremont-Winema National Forest, Oregon. Thirteen cattle exclosures were deployed along Jack Creek in...
Esmond Creek is a tributary to the Siuslaw River located in the Oregon Coast Range. It is 18 km in length and drains a watershed area is 48.9 km². Average channel gradient of the study reach is 0.9%. In 1988 a landslide
occurred in the Esmond Creek watershed involving approximately...
Mark-recapture methods were used to examine watershed-scale survival rates of coastal cutthroat trout (Oncorhynchus clarkii clarkii) from two headwater stream networks located in the foothills of the Cascade Mountain Range, Oregon. Differences in survival were explored among spatial (stream segment, stream network [main stem or tributaries], and watershed) and temporal...
Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in...
This dissertation is a collection of three manuscripts that serve to fill the knowledge gaps and advance methods of detecting the effects of contemporary forest harvesting in experimental catchment studies. While there is a preponderance of studies evaluating the environmental effects of forest harvesting in the western United States, few...
Information about forest substrate respiration, nitrogenase activity and
mineralizable nitrogen may be incorporated into carbon and nitrogen budgets that comprise an important element of forest management planning. In this study, substrate respiration, nitrogenase activity and mineralizable nitrogen were measured in two western Oregon Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] stands within...
Land use alters the physical and biological structure of stream ecosystems and potentially alters their capacity to process nitrogen (N), an essential nutrient that has nearly doubled in abundance on the biosphere
during the past century from human activities. In this dissertation, I quantified uptake and transformation of nitrate (NO₃⁻)...
Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and...
In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded standard aquatic habitat variables and water nutrient concentrations (nitrate and phosphate) and correlated them with fish and amphibian...
The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically
inventoried 158...
An 18-year record of nitrate (NO₃), orthophosphate, total nitrogen and total phosphorus in four streams of the Bull Run
watershed, Oregon, was examined to determine its precision and time resolution. Of these four species, only NO₃ was found to be known to a sufficient level of detail for modeling and...
Wildfire is a largely terrestrial perturbation broadly recognized as an agent of disturbance and ecological change in forested biomes. Effects of post-fire conditions on biotic components of aquatic systems have been less well-documented, although hypothetically, the two are strongly connected. In fact, the influence of wildfire may be most profound...
The American beaver (Castor canadensis) was nearly extirpated by the late 1800's due to the fur trade. Due to reintroduction efforts, it now occupies much of its former range. Beavers are a keystone species and ecosystem engineers, greatly influencing riparian and instream habitats through selective harvesting of plant materials and...
