A quick overview of beaver-assisted and inspired restoration of riverscapes focused on low-tech process-based restoration.

Part of ASWM Beaver Webinar Series: https://www.aswm.org/aswm/aswm-webinarscalls/3355-2020-past-beaver-restoration-webinar-series This second webinar in the ASWM-BLM Beaver Restoration Webinar Series focuses on making decisions about where beaver restoration and/or the use of beaver dam analogs (BDA) can have the greatest positive and least negative impacts. Understanding that beaver restoration is not well-suited for all contexts and purposes, this webinar will discuss risk assessment and introduce participants to the primary elements required to assess the efficacy of beaver projects for specific watersheds and sites. The webinar will cover how data can be used to make decisions about different kinds of flow devices and when beaver mimicry/BDAs make more sense. The webinar will include a demonstration of Utah State University’s Beaver Restoration Assessment Tool (BRAT), a model that helps planners assess key parameters (such as human interaction, hydrological setting, etc.) essential to beaver work. The webinar will end with discussion about the importance of post-construction monitoring.

These slides are from a webinar to Society for Ecological Restoration (https://www.ser.org/page/SERWebinars) and audience of ecological restoration practitioners. It focuses on three themes of health, healing and hope through the lens of some principles of what constitutes healthy riverscapes and principles of low-tech process based restoration.

Eurasian beaver (Castor fiber) populations are expanding across Europe. Depending on location, beaver dams bring multiple benefits and/or require management. Using nationally available data, we developed: a Beaver Forage Index (BFI), identifying beaver foraging habitat, and a Beaver Dam Capacity (BDC) model, classifying suitability of river reaches for dam construction, to estimate location and number of dams at catchment scales. Models were executed across three catchments, in Great Britain (GB), containing beaver. An area of 6747 km2 was analysed for BFI and 16,739 km of stream for BDC. Field surveys identified 258 km of channel containing beaver activity and 89 dams, providing data to test predictions. Models were evaluated using a categorical binomial Bayesian framework to calculate probability of foraging and dam construction. BFI and BDC models successfully categorised the use of reaches for foraging and damming, with higher scoring reaches being preferred. Highest scoring categories were ca. 31 and 79 times more likely to be used than the lowest for foraging and damming respectively. Zero-inflated negative binomial regression showed that modelled dam capacity was significantly related (p = 0.01) to observed damming and was used to predict numbers of dams that may occur. Estimated densities of dams, averaged across each catchment, ranged from 0.4 to 1.6 dams/km, though local densities may be up to 30 dams/km. These models provide fundamental information describing the distribution of beaver foraging habitat, where dams may be constructed and how many may occur. This supports the development of policy and management concerning the reintroduction and recolonisation of beaver.