The Impact of Contemporary Forest Practices on Stream Temperature at a Watershed Scale: A case study from Hinkle Creek
Skaugset, A.

One of the overarching objectives of the Hinkle Creek Paired Watershed Study was to investigate the impact of contemporary forest practices on stream temperature for non-fish-bearing streams and the cumulative impacts downstream on the fish-bearing tributaries and the main stem. This presentation is a large collection of data gathered about to conditions in Hinkle including canopy closure, minimum and maximum daily temperature, residence time, and groundwater influx. Statistically significant decreases in minimum daily temperature were detected for all of the treatment streams. Clearcuts adjacent to the fish-bearing tributaries and the main stem resulted in statistically significant increases and decreases to maximum daily stream temperatures. There was no empirical evidence that the changes in stream temperature detected at the scale of individual stream reaches were propagated downstream.

DISCIPLINE: Hydrology & Water Quality    STUDY: Hinkle Creek    TYPE: Presentations    TAGS: Canopy closure, minimum and maximum daily temperature, residence time, groundwater influx, Stream temperature
The Importance of Location: Responsiveness of Stream-living Fish Populations
Penaluna B., S. Railsback, J. Dunham, S. Johnson, A. Skaugset, and R. Bilby

The evolution of concepts in stream ecology has resulted in a collective recognition that location within a landscape matters to aquatic biota. Although it is known that location-related conditions have implications for aquatic biota, the contribution of location that most greatly influences a population has yet to be understood. Stream-living fish populations in headwater stream locations are affected by a juxtaposition of influences between more dynamic environmental regimes (i.e., flow, temperature, turbidity) and relatively fixed site-specific physical characteristics of streams also referred to as the physical ‘habitat template’ (e.g., channel geomorphology, instream habitat). Simulation experiments using the inSTREAM individual-based coastal cutthroat trout (Oncorhynchus clarkii clarkii) population model explored the role of environmental regimes and a habitat template for four headwater streams in the Trask River Watershed. We paired the suite of historic environmental regimes (i.e., flow, temperature, turbidity) from each site with the habitat template from each site (i.e., channel shape, velocity shelter availability, spawn gravel availability, distance to hiding refuge) using a full factorial design resulting in 16 different scenarios for both summer and winter over 4 years. We present evidence demonstrating that the role of the habitat template predetermines population dynamics by setting hierarchical boundaries to alternative environmental regimes.

DISCIPLINE: Fisheries    STUDY:    TYPE: Presentations    TAGS:
Local & Downstream Impacts of Contemporary Forest Harvesting Practices on Watershed Hydrology
Zègre, N.

This study measured the impacts of two harvest entries on the monthly streamflow and other measures of the streams below and adjacent to harvest.  Statistically significant increases in sediment yield, as suspended sediment, were detected as a consequence of timber harvest in the South Fork Hinkle Creek. These increases were detected at the small, headwater watershed scale as well as the large watershed scale. Unlike the increases in water yield, these increases were not consistent with the literature. The results of the seminal paired watershed studies showed very large increases in sediment yield, often as much as two or three times greater than sediment yields before timber harvest. The results from contemporary forest practices are much more muted and the increases are in the range of 20 to 30 percent increases in sediment yield. The increases are in order with and correlate well with the increases in water yield. That the increases in sediment yield are a result of increased stream power due to increases in water yield is a reasonable hypothesis to put forward to explain these observations. The greatest improvement in forest practices over the past several decades were directed toward reducing the impacts of timber harvest on sediment yield. These improvements include; clearcut size limits and adjacency constraints, improved yarding systems (in this case slackline, skyline cable systems), the prescription of buffer strips, and changes in site preparation practices.

DISCIPLINE: Hydrology & Water Quality    STUDY: Hinkle Creek    TYPE: Presentations    TAGS: Streamflow, peak flow, Harvesting effects, timber harvest, Headwater streams
Stream Temperature Pattern and Process in the Trask Watershed Study: Pre-Harvest
Reiter M., S. Johnson, and P. James

The Trask Watershed Study is a multi-disciplinary, long-term research project in the Oregon Coast Range that is designed to examine the effects of current forest management practices on aquatic ecosystems. Extensive physical (e.g., water quantity and quality, channel morphology) and biological data (e.g., primary productivity, macro-invertebrate communities, amphibian movement and fish populations and behavior) has been collected in both the small and large watersheds since 2006 and will continue until 2016. One of these key parameters we have been collecting at multiple scales is stream temperature.
Understanding the variability in stream temperature patterns and processes prior to harvest in both small non-fish headwater streams and downstream in larger fish-bearing basins allows us to anticipate potential responses to harvest and subsequent potential changes in biota. Using the pre-harvest stream temperature data we examine variability in maximum and minimum temperatures across the 15 small headwater streams. We also examine how well both small treatment streams and the larger downstream basins correlate to un-harvested reference streams to determine the best match to compare post-harvest response. Finally we examine how stream temperature patterns vary longitudinally in the downstream direction through time.

DISCIPLINE: Hydrology & Water Quality    STUDY: Trask    TYPE: Presentations    TAGS:
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