Stream restoration practitioners are increasing working to use restoration approaches that mimic and restore natural processes. One such approach that is becoming common across the western U.S. is to install beaver dam analogs made out of wood and mud to restore degraded streams and store more water and sediment on the landscape. Ideally, these structures restore a stream to the point where beavers may re-establish and then further aid with stream restoration and water storage. Beaver dams and beaver dam analog structures do a great job at turning once incised and eroded streams to complex stream habitats that serve as critical habitat for many species.
However, there are still a number of concerns regarding beaver mimicry due to various gaps in the science surrounding the practice. Specifically, biologists are concerned that as drought continues to be more common that more impoundments on the landscape may increase water temperatures, reduce stream connectivity for stream biota, and have potential negative effects on trout populations through reducing spawning sites quality and/or increasing habitat for nonnative species.
In collaboration with Katie Racette and Will McDowell (Clark Fork Coalition), Steve Kloetzel (The Nature Conservancy), Traci Sylte (Lolo National Forest), and Montana Fish Wildlife and Parks, researchers at the University of Montana have identified potential project areas with restoration needs where we can investigate the range of effects this restoration practice may have in Western Montana. Researchers will be studying the potential for complexes of beaver dam analogs in headwater streams to increase ecosystem resilience to climate change by increasing the water storage capacity and persistence of cool water habitats into the late season. Research will also focus on fish movement and habitat, as well as the amount and types of carbon stored within and moving through streams with and without BDAs.
In the summer of 2019, Lisa Eby (UM BRIDGES faculty), Ben Colman (UM BRIDGES faculty), Andrew Lahr (Wildlife Biology PhD student and UM BRIDGES trainee), and undergraduate researchers Kenna Karjala, and Hayden Cody (Ecosystem Science and Restoration and Wildlife Biology) have completed the first year of pre-installation monitoring.
In October 2019, the students in the Elements of Ecological Restoration Class performed a service learning field trips to work with the Clark Fork Coalition installed 26 analog structures across 3 restoration project areas. It was a great hands-on learning experience for the students – even as they worked, structures were already visibly slowing and storing water!
We are excited to see how these structures alter population and ecosystem processes. This is a great example of the interlinkages among teaching, research, and restoration practice!
Pictured: Undergraduate students in the Elements of Ecological Restoration Class (NRSM 265), installing beaver mimicry structures with Will McDowell and Katie Racette (Clark Fork Coalition, stream restoration practitioners), Andrew Lahr (Wildlife Biology Bridges PhD student), and Lisa Eby (UM Professor).
BRIDGES Blog 