This research is being conducted by Shyloh van Delft, a Master’s student at Yukon University/University of Alberta.
Wildfire is vital for the health of northern boreal forests. However, climate warming is making wildfires in the North more severe. Bigger, hotter, more frequent fires can harm ecosystems, the natural resource economy, and threaten communities, infrastructure, and heritage sites. Wildfire risk is being mitigated by reducing burnable material in coniferous forests through fire-smarting (thinning), clearing, harvesting, and controlled burning of trees and understory. However, the ecological impacts of these treatments are relatively unknown in northern ecosystems.
A wide variety of northern bird, mammal and insect species use cavities in trees as nest sites, and for shelter and food storage. These cavities may occur through natural tree decay processes or through excavation by woodpeckers. Tree cavities are critical for the survival and reproduction of many northern animal species, including several small furbearers (e.g., marten, squirrels, ermine, etc.) and species at risk or of conservation concern (e.g., Little Brown Bat, American Kestrel, etc.). However, tree cavities may be a limited resource for many cavity-using species in the north due to the small size of trees in northern boreal forests and slow decay processes. Additionally, trees with cavities may be directly affected by wildfire prevention treatments. The loss of even a limited number of trees with cavities may have a substantial impact on wildlife populations that use them. Therefore, understanding the impacts of forest fuel treatments on cavity users is critical and time-sensitive for the conservation of these fragile northern communities.
The project objectives are to: 1) determine the composition and structure of the tree cavity-using community in intact northern boreal forest and examine changes in response to forest fuel treatments, 2) identify cavity and habitat characteristics preferred by tree cavity-users in relation to cavity availability and disturbance, and 3) identify the initial effects of forest fuel treatments on the composition and structure of tree cavity-using communities and on the presence and abundance of other wildlife species. Field work will be conducted beginning in 2025 to examine tree cavity availability and use in forest fuel treatment areas before and after treatment, and in untreated control areas. In addition, historic cavity-use data from long-term monitoring of artificial nest sites (nest boxes) will be analyzed to provide baseline information on cavity users in the Yukon.
This research is supported by Ta’an Kwäch’än Council, Kwanlin Dün First Nation, Yukon Government’s Wildland Fire Management branch, the City of Whitehorse, Environment and Climate Change Canada, Yukon Bird Club, and Wildlife Conservation Society Canada. Funding for this project is provided by the W.A. Burnham Memorial Fund of The Peregrine Fund, Yukon University, and University of Alberta.
