Oral Presentations and Performances: Session II
Project Type
Presentation
Project Funding and Affiliations
Irene Evers Undergraduate Research Scholarship
Faculty Mentor’s Full Name
Lisa Eby
Faculty Mentor’s Department
Aquatic Ecology
Abstract / Artist's Statement
Beavers are ecosystem engineers who influence the geomorphology and hydrology of streams, as well as riparian vegetation. Beaver-related restoration has become a popular approach with techniques such as beaver dam analogs (BDAs) commonly used to aid in the recovery of stream ecosystems. Despite their extensive use in low-tech restoration, there exist few studies longer than 3 years to demonstrate the effectiveness of BDAs. We conducted a 6-year follow-up study on a project with 14 BDAs in Teepee Creek, a second-order stream near Lolo in Western Montana. We collected data on instream habitat, flow, water temperature, and riparian vegetation and analyzed it using a Before, After, Control, and Impact study design. Compared to the control reach, the restored reach had greater channel heterogeneity with more islands, bars, and wood in the stream. The percent bank area covered by woody vegetation and sedges in the restored reach increased over 6 years, while these vegetation types stayed the same or decreased upstream, indicative of greater groundwater close to the stream. The restored reach supported more surface water (pools) and higher flows later into the year compared to the upstream control, but there were no changes in temperature as water flows through the restored reach. Overall, the beaver dam analog project increased residence time, riparian plants, and channel heterogeneity. These results support expected, positive changes in restored streams 6 years after the project installation as stream channels increase in complexity, reconnect to floodplains, and improve riparian habitat.
Category
Physical Sciences
Multiyear stream and riparian responses to beaver dam analogs in a headwater tributary
UC 329
Beavers are ecosystem engineers who influence the geomorphology and hydrology of streams, as well as riparian vegetation. Beaver-related restoration has become a popular approach with techniques such as beaver dam analogs (BDAs) commonly used to aid in the recovery of stream ecosystems. Despite their extensive use in low-tech restoration, there exist few studies longer than 3 years to demonstrate the effectiveness of BDAs. We conducted a 6-year follow-up study on a project with 14 BDAs in Teepee Creek, a second-order stream near Lolo in Western Montana. We collected data on instream habitat, flow, water temperature, and riparian vegetation and analyzed it using a Before, After, Control, and Impact study design. Compared to the control reach, the restored reach had greater channel heterogeneity with more islands, bars, and wood in the stream. The percent bank area covered by woody vegetation and sedges in the restored reach increased over 6 years, while these vegetation types stayed the same or decreased upstream, indicative of greater groundwater close to the stream. The restored reach supported more surface water (pools) and higher flows later into the year compared to the upstream control, but there were no changes in temperature as water flows through the restored reach. Overall, the beaver dam analog project increased residence time, riparian plants, and channel heterogeneity. These results support expected, positive changes in restored streams 6 years after the project installation as stream channels increase in complexity, reconnect to floodplains, and improve riparian habitat.