Beaver Pond Biogeochemistry and Non Point Source Pollution Mitigation
Beavers (Castor canadensis) bridge aquatic and terrestrial environments by harvesting woody materials to dams that flood entire valley bottoms. Their unique lifestyle leads to variable in-stream flow rates, increased temperature variability, and leads to sediment entrapment, which consequently affects aquatic biogeochemistry, stream water quality and primary productivity. Currently, non-point source (NPS) pollutants represent the largest source of pollution to freshwater bodies in the United States, and specifically the Intermountain West. One potential solution for both mitigating NPS pollution in mountain streams and increasing the capacity for natural water storage is via increased number of beaver dam impoundments. Because beaver ponds slow stream flow and accumulate sediments, which bind many nutrients and pollutants they may also trap NPS pollutants from traveling downstream. However, beaver ponds have also been shown to act as nutrient sources, what controls source or sink behavior of a pond has not been clear. As beavers are rapidly reintroduced to their historical range, it is crucial for researchers and managers to understand both the positive and negative effects of beaver activity on stream water quality over multiple spatial and temporal scales. Our research has shown that beaver pond morphology fundamentally controls whether beaver ponds act as a source or sink for key nutrients. Ponds with larger, deeper, backwater areas not only facilitate the burial of P, N, and heavy metals, but also support denitrification, permanently removing nitrogen from the system. We also developed a theoretic framework to determine sediment-water interaction potential, and the net outcome of biogeochemical reactions. These frameworks can help land managers, land owners, and scientists manage nutrient resources and freshwater pollution. |
Publications and Thesis
**Brahney student/postdoc
*Student
**Murray, D., Neilson, B., Brahney, J. (2023) Beaver pond geomorphology influences sediment nitrogen retention and denitrification. Journal of Geophysical Research – Biogeosciences.
**Murray, D, Neilson, B., Brahney, J. (2021) Source or sink? Quantifying beaver pond influence on non-point source pollutant transport in the Intermountain West. Journal of Environmental Management. [IF 5.708, Cit:0]
Murray, D.S. (2021) The fate and cycling of nitrogen, phosphorus, and trace heavy metals in beaver-altered headwater streams. MS Thesis, Utah State University
**Brahney student/postdoc
*Student
**Murray, D., Neilson, B., Brahney, J. (2023) Beaver pond geomorphology influences sediment nitrogen retention and denitrification. Journal of Geophysical Research – Biogeosciences.
**Murray, D, Neilson, B., Brahney, J. (2021) Source or sink? Quantifying beaver pond influence on non-point source pollutant transport in the Intermountain West. Journal of Environmental Management. [IF 5.708, Cit:0]
Murray, D.S. (2021) The fate and cycling of nitrogen, phosphorus, and trace heavy metals in beaver-altered headwater streams. MS Thesis, Utah State University