Short-term Responses of Boreal Small Mammals to a Mega-fire in Central Yukon

Gabriel Rivest, Katie Aitken, Mark O’Donoghue, Tom Jung, Fiona Schmiegelow

Forest fire regimes are significantly changing globally, primarily due to climate change. Rising temperatures and extended droughts have intensified fire weather conditions, leading to more frequent, severe and expansive wildfires across various ecosystems. These conditions have been observed extensively in the western boreal forest of North America, with fires becoming larger, more severe, and occurring at shorter intervals. Large wildfires of over 10,000 ha, also known as mega-fires, are becoming more frequent and more prominent on the landscape. These mega-fires often surpass historical fire behavior in scale and severity, leading to ecological consequences, including shifts in vegetation regimes, soil degradation, and disruptions to carbon storage dynamics. Despite their increasing frequency, the recent nature of these events makes it challenging to understand the long-term effects these fires may have on biological diversity and ecosystems. Research on mega-fires is essential to filling this knowledge gap and informing adaptive strategies to mitigate risks to biodiversity. Understanding how wildfires influence small mammal abundance and community composition is of significant ecological importance, particularly in fire prone ecosystems such as the boreal forest. Small mammals serve critical roles in ecosystem functioning, including seed dispersal, soil alteration, fungal spore distribution, and serving as prey for higher trophic levels making them a key part of the energy flow in boreal forests.