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Abstract Beavers (Castor canadensis) are rapidly colonizing the North American Arctic, transforming aquatic and riparian tundra ecosystems. Arctic tundra may respond differently than temperate regions to beaver engineering due to the presence of permafrost and the paucity of unfrozen water during winter. Here, we provide a detailed investigation of 11 beaver pond complexes across a climatic gradient in Arctic Alaska, addressing questions about the permafrost setting surrounding ponds, the influence of groundwater inputs on beaver colonization and resulting ponds, and the change in surface water and aquatic overwintering habitat. Using field measurements, in situ dataloggers, and remote sensing, we evaluate permafrost, water quality, pond ice phenology, and physical characteristics of impoundments, and place our findings in the context of pond age, local climate, permafrost setting, and the presence of perennial groundwater inputs. We show beavers are accelerating the effects of climate change by thawing permafrost adjacent to ponds and increasing liquid water during winter. Beavers often exploited perennial springs in discontinuous permafrost, and summertime water temperatures at spring‐fed (SF) beaver ponds were roughly 5°C lower than sites lacking springs (NS). Late winter liquid water was generally present at pond complexes, although liquid water below seasonal ice cover was shallow (5–82 cm at SF and 5–15 cm at NS ponds) and ice was thick (median: 85 cm). Water was less acidic at SF than NS sites and had higher specific conductance and more dissolved oxygen. We estimated 2.4 dams/km of stream at sites on the recently colonized (last ~10 years) Baldwin Peninsula and 7.4 dams/km on the Seward Peninsula, where beavers have been present longer (~20+ years) and groundwater‐surface water connectivity is more common. Our study highlights the importance of climatic and physiographic context, especially permafrost presence and groundwater inputs, in determining the characteristics of the Arctic beaver pond environment. As beavers continue their expansion into tundra regions, these characteristics will increasingly represent the future of aquatic and riparian Arctic ecosystems.
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Game Camera Footage of Beaver-Impacted Streams on the Baldwin Peninsula, Alaska, August 2023-April 2024
### Access Data files can be accessed and downloaded from the directory via: [https://arcticdata.io/data/10.18739/A2M03Z00G](https://arcticdata.io/data/10.18739/A2M03Z00G) ### Overview Emergence of beavers as ecosystem engineers in the New Arctic project focuses on establishing field sites at tundra beaver ponds to study the implications of beaver engineering on ecosystems. We established three game camera sites at beaver-impacted streams on the Baldwin Peninsula from August 2023-April 2024. We aimed to collect information regarding ice formation phenology, overflow dynamics, and wildlife interactions. Two cameras were deployed adjacent to beaver dams, and another was deployed at a "control" site in a part of a stream that remains unimpacted by beavers. Cameras were set in a hybrid setting, collecting images through timelapse and trigger settings. Two cameras (Moultrie brand) lost power in early December, and one (Bushnell brand) maintained power over the entire study period. Cameras captured ice formation dynamics in early fall, as well as a series of overflow events. From this rudimentary data set, we did not detect differences in ice formation between ponds and the control site. We were also able to detect a dam bursting event following an August rain storm, which beavers did not repair before winter. Cameras captured a variety of wildlife, including red foxes, moose, brown bears, Canada geese, green-winged teal, and, of course, beavers.
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- Award ID(s):
- 2114051
- PAR ID:
- 10536134
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- Beaver Pond Stream Arctic Baldwin Peninsula Alaska Tundra Ice Formation Overflow Wildlife Game Camera
- Format(s):
- Medium: X Other: text/xml
- Sponsoring Org:
- National Science Foundation
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