Presentation Type
Presentation
Faculty Mentor’s Full Name
Ben Colman
Faculty Mentor’s Department
W.A. Frank College of Forestry and Conservation
Abstract / Artist's Statement
Ninemile Creek in Western Montana has been highly degraded by placer mining that took place from the 1800s to 1960s, resulting in a straightened stream disconnected from its floodplain by 10 m tall gravel piles. This degradation decreases water storage and makes the habitat less suitable for aquatic organisms. To improve habitat quality, Trout Unlimited has reconfigured four reaches along the creek starting in 2014 to create a new river channel and connected floodplain with two years between each restoration project. Due to the physical disturbance of reconfiguring the stream channel and building the floodplain, plant communities were reset in each reach to an early successional stage. A study conducted in 2019 showed that succession in the plant community proceeds gradually but seemed to accelerate in the one reach where beavers had built dams. In that reach, there was more soil organic matter and higher plant cover. However, beaver can also have negative impacts on vegetation in that they use it for food and building materials. Also, if they create persistent flooding, it can have negative impacts on vegetation. In the two years since the previous study, beaver have begun moving down valley and may have built dams in other restoration phases. We propose to further examine the influence of time and beaver activity on the succession in restored reaches of Ninemile Creek. Specifically, we will map beaver dams and lodges to determine the extent of their influence, we will quantify both plant community composition and cover, and we will measure soil organic matter concentration. This study will provide information to managers to help them better evaluate the interplay between time and beaver activity in driving the pace of recovery for similar restored stream reaches.
Category
Life Sciences
Assessing the role of time and beavers in driving recovery following restoration
Ninemile Creek in Western Montana has been highly degraded by placer mining that took place from the 1800s to 1960s, resulting in a straightened stream disconnected from its floodplain by 10 m tall gravel piles. This degradation decreases water storage and makes the habitat less suitable for aquatic organisms. To improve habitat quality, Trout Unlimited has reconfigured four reaches along the creek starting in 2014 to create a new river channel and connected floodplain with two years between each restoration project. Due to the physical disturbance of reconfiguring the stream channel and building the floodplain, plant communities were reset in each reach to an early successional stage. A study conducted in 2019 showed that succession in the plant community proceeds gradually but seemed to accelerate in the one reach where beavers had built dams. In that reach, there was more soil organic matter and higher plant cover. However, beaver can also have negative impacts on vegetation in that they use it for food and building materials. Also, if they create persistent flooding, it can have negative impacts on vegetation. In the two years since the previous study, beaver have begun moving down valley and may have built dams in other restoration phases. We propose to further examine the influence of time and beaver activity on the succession in restored reaches of Ninemile Creek. Specifically, we will map beaver dams and lodges to determine the extent of their influence, we will quantify both plant community composition and cover, and we will measure soil organic matter concentration. This study will provide information to managers to help them better evaluate the interplay between time and beaver activity in driving the pace of recovery for similar restored stream reaches.