Post-fire forest management relies primarily on visible indicators of tree damage to classify burn severity and estimate survival. These assessments assume that observable injury reflects internal physiology and long-term recovery potential. However, this assumption is limiting, as trees that appear structurally intact can undergo internal changes that predispose them to delayed mortality or secondary disturbances.
Molecular characterization of sapwood fungal communities provides a biologically grounded alternative to external assessments. While most post-fire microbial research has focused on soil processes, wood-inhabiting fungi play a direct role in host nutrient cycling and stem integrity. They modify structural tissues, influence defense chemistry, and interact with bark beetles and other wood-boring insects that frequently colonize fire-weakened trees. As a result, shifts in these communities may reveal early signs of tree vulnerability that are not captured by visual metrics alone.Â
Fungal community composition is expected to vary with burn severity, host species, and time since disturbance. Lower severity fires may favour opportunistic or insect-associated fungi, whereas higher severity burns may promote saprotrophic taxa associated with tissue degradation. Host identity may further shape these responses, with deciduous aspen exhibiting distinct post-fire trajectories compared to conifers such as lodgepole pine and white spruce. Changes through time may indicate whether trees are stabilizing or progressing toward decline.
Sapwood fungal communities can be reliably characterized using ITS metabarcoding, providing a practical tool for assessing post-fire tree condition. These communities can inform management decisions by distinguishing trees likely to recover from those at risk of delayed mortality, identifying fire severity conditions that promote recovery, and determining optimal timing for interventions. Integrating fungal indicators into post-fire assessments offers a biologically informed framework for improving long-term forest resilience.
To support these management decisions, the following research objectives were explored:
Improve post-fire retention and salvage decisions by identifying sapwood fungal indicators that predict delayed tree mortality beyond visible burn severity.
Guide forest resilience planning by identifying fire severity conditions that promote sapwood fungal communities associated with tree recovery.
Optimize the timing of post-fire management interventions by using sapwood fungal indicators across years following fire.