Impacts of short-interval wildfire on forest regeneration in Glacier National Park, British Columbia

The inland northwest will see a doubling in the occurrence of wildfires by the end of the 21st century, an increase in extreme burning conditions, and more severe mega-fires. Ecological impacts of more frequent wildfires can include fewer trees regenerating post-fire, shifts in forest type, and forests converting to other types of ecosystems. High-elevation mountain forests (1,200-2,300 m asl) in the inland northwest typically experience wildfire once every 100-200 years, but with changing climatic conditions projections indicate shorter intervals between fire events (<30 years). To characterize the ecological impacts of short-interval wildfires on high-elevation forests, we assessed vegetation regeneration across 74 plots in Beaver Valley, Glacier National Park (1,349 km2), Canada. Plots were distributed across areas affected by no fire, a single wildfire (2017), and two wildfires (1992 and 2017). Further, we determined whether the order of burn severities (low or high-severity) influences forest regeneration (e.g., two consecutive high-severity wildfires).

Preliminary results suggest that two consecutive high-severity wildfires resulted in minimal canopy regeneration, demonstrating the influence of order and severity on early stages of post-fire regeneration. These insights will better characterize how short-interval wildfires impact forest regeneration and forest resilience to climate change.