Suspended Sediment Concentrations and Turbidity Responses from Contemporary Road Crossings in the Trask River Watershed
Arismendi I., J. D. Groom, S. L. Johnson, M. Reiter, L. De

Road-related turbidity and suspended sediments is a concern for both commonly occurring and higher magnitude storm events with the potential to negatively affect in-stream biota. Here, we present preliminary results that address whether forest road crossings deliver fine sediments into streams. Specifically, we evaluate evidence of sediment routing before/after road interventions (including new roads and road upgrades - surfacing with gravel) and above/below road crossing within forest harvest units. We hypothesize that newly constructed and upgraded roads will increase turbidity and suspended sediments where roads have hydrologic connections to streams. This response will be heightened during high intensity precipitation. We measured suspended sediment and turbidity above and below road crossing and before (June 2010-Apr 2011) and after (July 2011-June-2012) road upgrades using ISCO samplers in five headwater streams from small-sized watersheds (5-36 ha). We complemented this information with available data from hydrology (four flume stations) and precipitation (two climate stations) during the same time periods. We examined statistical differences of in-stream turbidity and concentrations of suspended sediments below and above road crossing and characterized the behavior of sites before and after road upgrades.

DISCIPLINE: Hydrology & Water Quality    STUDY: Trask    TYPE: Presentations    TAGS:
Alsea Watershed Study and Alsea Watershed Study Revisited
Brown G.

The original Alsea Basin Logging and Aquatic Resources Study (1959-1973) was established in response to public and legislative concerns about the impact of timber harvesting and road construction on salmon. It was the first paired watershed study in North America to document these impacts. The study design utilized one watershed (Flynn Creek) as an untreated control for the duration of the study. Deer Creek was roaded and harvested with three small patch clearcuts covering about 25% of the basin. Harvest boundaries were kept 50 feet or more from the stream banks. The small clearcuts received a light slash fire following logging. Needle Branch was roaded and completely clearcut without stream protection buffers and, following logging, was burned with a very hot slash fire and channel cleaned of debris, which typified the logging practices of the day. Before and after treatments, streamflow, water quality and aquatic resources were carefully monitored on all three watersheds. Changes in streamflow, water quality and aquatic resource populations were small after road construction and logging in Deer Creek, even with the very narrow stream protection buffers. Large changes in water quality and suspended sediment were recorded after clearcutting without stream protection and the hot slash fire in Needle Branch. Temperature and suspended sediment levels returned to pretreatment levels within five years. Cutthroat trout numbers decreased significantly.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS:
Alsea Watershed Study Revisited: Hydrologic Response to First Harvest
Hale V. C., G. Ice, J. Stednick, J. Light, and N. Zègre

The hydraulic response of the Alsea watershed study to the first harvest produced results to in the streamflow of Needle Branch creek. Deer creek was shown to be a suitable control and that Upper and Lower Needle Branch respond similarly. There is still a lot of work to be done and suspended sediment analysis to complete.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS:
The Alsea Paired Watershed - Revisited: Harvest Effects on Stream Temperatures
Light J., G. Ice, V. C. Hale, J. McDonnell, and M. Teply

This project explores the effects of harvesting on the temperature of the fish bearing streams. It also draws comparisons to the historical effects of the old best management practices in comparison to contemporary beast management practices. Some warming was found but significantly less than what had been found in old projects.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS:
Dissolved Oxygen Response to Forest Management in the Alsea Watershed Study Revisited
Ice G., V. C. Hale, T. Bousquet, A. Simmons, G. Brown, and D. Lee

The original Alsea Watershed Study found dissolved oxygen (DO) concentrations at or near saturation in the control (Flynn Creek) and patchcut and buffered (Deer Creek) watersheds. DO concentrations in some reaches of the clearcut and unbuffered watershed (Needle Branch) were found to be substantially below saturation following the 1966 harvest. The depressed concentrations were thought to result from a combination of increased biochemical oxygen demand, reduced solubility due to stream heating, increased biological activity, and reduced reaeration. The Alsea Watershed Study Revisited (AWSR) returns to the same watersheds and provides an assessment of physical, chemical, and biological response to contemporary forest practices. During the pre-treatment phase of the AWRS low DO concentrations were observed in Needle Branch in the summer and fall. These low concentrations coincided with low flow periods. At these times flow becomes “discontinuously perennial” and portions of the stream network go subsurface. We now believe that despite having some of the highest reaeration rates ever measured, certain reaches of Needle Branch are prone to depressed DO concentrations. For some reaches, surface flow during critical late season periods is largely composed of recently emerged groundwater or hyporheic water. Both original study and AWSR findings show high spatial variability in DO concentrations.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS: Dissolved Oxygen, fish distribution, perennially-flowing, groundwater, discontinuously perennial
Nutrient Response to Contemporary Forest Practices Regulations
Stednick J. D., V. C. Hale, G. Ice, D. Cook, T. Bousquet, and J. Light

The original Alsea Watershed Study measured water quality before and after logging. For Deer Creek with patchcuts and streamside vegetation buffers, there were no changes in water quality post-harvesting. Needle Branch was harvested without streamside buffers and the slash burned. Nitrate concentrations increased from 0.70 to a maximum of 2.10 mg/L, and returned to pretreatment levels by the 6th year after logging. The loss of nitrogen was negligible when compared to the nitrogen capital (soils and vegetation) and loss of terrestrial productivity was not anticipated. Additional water quality monitoring in the study watersheds identified spatial and temporal variations instream water quality. Of particular note is the influence of landscape elements including vegetation, soils, slope, and hydraulic conductivity as related to water quality, particularly nitrogen. Also the first significant fall storm flushes oxidized nitrogen from the soil profile and results in higher stream water nitrate concentrations. The Alsea Watershed Study Revisited (AWSR) provides an assessment of water quality response to contemporary forest practices. Nested watersheds in Needle Branch, including immediately below the harvest unit (NBU) and the original gauge (NBL) were compared for water quality changes. During the pre-treatment monitoring, nutrient concentrations at NBU were generally higher but paralleled concentrations at NBL.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS: Nitrate concentration, ammonia, phosphorus
Herbicides in Needle Branch Streamwater
Louch, J., G. Allen, G. Ice, T. Garland, V. C. Hale, and J. McDonnell

Glyphosate, aminomethylphosphonic acid (AMPA), imazapyr, sulfometuron methyl, and metsulfuron methyl were measured in Needle Branch streamwater during and after application of herbicide(s). All herbicides were applied by helicopter in a single tank mix. Samples were collected at three sites: NBH (at the fish/no-fish interface in the middle of the harvest unit), NBU (at the bottom of the harvest unit), and NBL (well downstream). AMPA, imazapyr, sulfometuron methyl and metsulfuron methyl were not detected in any sample at 15 ng/L, 0.6 μg/L, 0.5 μg/L and 1 μg/L, respectively. However, a clear pulse of dissolved glyphosate manifested at NBH during the application (baseflow conditions).  Subsequent baseflow samples collected three days after treatment (DAT) showed ≈25 ng/L dissolved glyphosate at all three sites. Samples collected during the first storm event (8 DAT) showed a clear pulse of dissolved glyphosate at NBU, but not at NBH or NBL. The maximum concentration observed during this pulse at NBU was 115 ng/L, and the pulse persisted for about six hours. During the next storm event (10 DAT) a clear pulse of dissolved glyphosate manifested at NBH, but not at NBU or NBL. The maximum co centration observed was 42 ng/L, and this pulse persisted for about ten hours. Results from all subsequent storm events showed dissolved glyphosate at <20 ng/L in all samples. A limited number of analyses on suspended sediment (SS) showed that SS held de minimis masses of glyphosate and AMPA.

DISCIPLINE: Hydrology & Water Quality    STUDY: Alsea    TYPE: Presentations    TAGS: Glyphosate, herbicides, aerial application
Nutrient Dynamics
Meininger, W. S.

Nutrients are one of the factors which limit primary production and can be a water pollutant. Fertilizer can be applied to increase the Nitrogen and therefore increase the growth. The Hinkle Creek Paired Watershed Study addresses concerns about the loss of essential plant nutrients in Douglas-fir plantations and assesses the impacts of forest management on stream water chemistry of fish-bearing streams. The objective is to determine the cumulative impacts to fish-bearing streams of non-fish-bearing streams which are not afforded the protection of un-harvested and unfertilized riparian strips and to compare those impacts with the local impacts of different treatments.

DISCIPLINE: Hydrology & Water Quality    STUDY: Hinkle Creek    TYPE: Presentations    TAGS: Nutrients, Primary Production, Contemporary Forest Management, Paired Watershed, Nitrate Response, Longitudinal attenuation
Sediment Symposium: Quantifying In-Stream Sediment and Biotic Responses Presentation Videos

At the Sediment Symposium, researchers review and summarize our overall understanding of current scientific knowledge of in-stream sediment. The video archive of the presentations is available.

To view the presentations, please visit this website:  http://oregonstate.edu/conferences/event/2013sedimentsummit/videoarchive...

DISCIPLINE: Disciplinary Results    STUDY: Alsea, Hinkle Creek, Trask    TYPE: Presentations    TAGS: Conference, Video, Sediment, Stream, Turbidity, Macroinvertebrate, Amphibian, Road, Fish, Oregon
Arthropod Prey for Riparian Associated Birds in Headwater Forests of the Oregon Coast Range
Hagar J.C., J. Li, J. Sobota, S. Jenkins

Streamside habitat is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability.

DISCIPLINE: Wildlife    STUDY: Trask    TYPE: Journal Articles    TAGS: Bird, arthropod prey, aquatic insects, understory