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.

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.

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.

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.