Thermal Regimes of Beaver-Impacted Stream Reaches in the Tualatin River Basin, Oregon, United States
Sponsor
Funding: This work was supported by Tualatin Soil and Water Conservation District (G202203-88). The National Science Foundation (1832109, 1832170). Additional funds and support were provided by Portland State University (PSU)'s WISE lab and the U.S. Geological Survey (USGS).
Published In
River Research and Applications
Document Type
Article
Publication Date
1-1-2025
Subjects
Stream restoration -- Oregon
Abstract
As beavers are increasingly used in stream restoration, interest in their potential to mitigate stream degradation has grown. However, the impacts of beaver dams on stream temperature remain inconsistent across studies, often due to differences in spatial scale and methodology. We investigated summer thermal regimes at multiple spatial scales in three beaver-impacted streams within the Tualatin River Basin, Oregon, using fiber-optic distributed temperature sensing. Substantial variability in thermal regimes was observed among the three stream reaches and around individual beaver dams within each reach. This variability was primarily influenced by geomorphic changes in stream depth associated with beaver dams and restoration history. The thermal sensitivity of stream temperatures to air temperatures significantly increased across the three sites, following a gradient of increasing time since restoration, beaver activity, and stream depth. Across all sites, stream depth was more strongly correlated with variability in daily maximum temperatures than canopy cover. This was most evident at Fanno Creek, where stream depth explained ~41% of the variability in daily maximum temperatures on August 16, 2023. Reach-scale measurements often masked fine-scale thermal heterogeneity with ecological implications. At the beaver dam scale, significant differences in daily maximum temperature and daily temperature range were observed among upstream, pond, and downstream locations, emphasizing the thermal variability induced by beaver dams over short distances. Our findings demonstrate that thermal regimes in beaver-impacted reaches are shaped by local geomorphic factors and vary with spatial scale, underscoring the importance of multi-scale approaches to assess the thermal effects of beaver activity.
Rights
Copyright (c) 2025 The Authors
This work is licensed under a Creative Commons Attribution 4.0 International License.
Locate the Document
DOI
10.1002/rra.70030
Persistent Identifier
https://archives.pdx.edu/ds/psu/44059
Citation Details
Mayer, M., & Chang, H. (2025). Thermal Regimes of Beaver‐Impacted Stream Reaches in the Tualatin River Basin, Oregon, United States. River Research and Applications. Portico.