Where the wild beavers are: Climate and landscape controls on beaver pond area in snow‐dominated rangeland headwaters

Abstract

Beavers are of increasing interest as a mechanism for ecosystem restoration. However, the physical watershed characteristics that allow for successful beaver re‐establishment are not consistent across habitat suitability models. We delineated the extent of beaver impounded surface water in the Pole Mountain Area (PMA) of south‐eastern Wyoming with six National Agricultural Imagery Program acquisitions over an 18‐year time period via a random forest classification algorithm. We computed beaver pond area for first‐ and second‐order watersheds within the PMA and related the impounded pond area to climatic metrics such as maximum annual snow water equivalent and snowmelt and rain input into the ground. There was no apparent relationship between annual climate metrics and beaver pond area. Further, we developed a random forest regression model to correlate beaver pond area with topographically derived watershed characteristics (e.g. hillslope size and riparian area size) to explore physical controls on impounded area at the watershed scale. Controls differed for first‐ and second‐order watersheds, with pond area in smaller watersheds largely being controlled by lateral water contributions from the hillslopes and in the larger watersheds by water from upstream and available space in the riparian areas. Interestingly, vegetation height did not emerge as an important predictor for pond area, likely because of generally good availability of forage material in all watersheds. This study improves our understanding of watershed characteristics that contribute to beaver habitat suitability and can be used to guide beaver reintroduction efforts through analysis targeted at identifying watersheds most appropriate to beaver pond construction.

A bibliometric literature review in beaver management: when does the beaver become a resource?

“…This category consists of 35 documents that applied habitat suitability model to guide beaver reintroduction, conservation, and management actions. Specifically, these documents present the application of different methods and algorithms to predict the suitability of a location for this rodent based on its needs and environmental conditions (Maringer & Slotta-Bachmayr 2006, Francis et al 2017, Smeraldo et al 2017, Swinnen et al 2017, Dittbrenner et al 2018, Stringer et al 2018, Treves et al 2020, Fitch et al 2022, Serva et al 2023. Moreover, habitat suitability models are used to 1) predict beaver dam occurrences, better understand dam site characteristics, and evaluate beaver dam carrying capacity (Macfarlane et al 2017, Petro et al 2018, Graham et al 2020, Kornse & Wohl 2020, Scamardo et al 2022; 2) predict beaver abundance (Beck et al 2010, St-Pierre et al 2017, Thompson et al 2022; 3) link riparian vegetation and beaver occurrence (Breck et al 2012); 4) identify potential threats for the beaver (Romanowski et al 2008).…”