OREGON STATE UNIVERSITY

Trask Study

The Trask Study takes a long term and multi-disciplinary approach to quantifying the effects of forest harvest on the physical, chemical and biological characteristics of small non‐fish headwater streams. The extent to which harvest on these small streams influences downstream fish reaches is also under exploration. Studies like this connect forestry management decisions to their actual responses instead of assuming a response from other related parameters.

The Trask Study design uses a nested paired watershed approach with both treatment and control basins. The reference watershed is left unharvested. Three treatment watersheds are harvested using contemporary best management practices (BMP). Although both fish-bearing and non-fish-bearing streams are being studied, harvest will only occur around the non-fish-bearing streams. 

The Trask study relies on extensive pre- and post-harvest data collection and monitoring. This includes at least four years before treatment, the harvest, and four years post-treatment. The ecosystem’s response to the harvest is monitored through its effects on fish, birds, stream temperature, suspended sediment, hydrology, and invertebrates.


This is a gauging station on Lower Trask.

The Trask Watershed study area works in outreach as well, offering tours for public, research, regulatory and environmental groups. The study is also presented at conferences.