Fire Effects and Fire Ecology

Background

Climate  change  is  altering  fire  regimes  and  post-fire  conditions,  contributing  to  relatively  rapid  transformation  of  landscapes  across  the  western  US.

Conifer forest resilience may be threatened by increasing wildfire activity and compound disturbances in western North America. Fire refugia enhance forest resilience, yet may decline over time due to delayed mortality—a process that remains poorly understood at landscape and regional scales.

The 2023 wildfire season in Canada was unprecedented in its scale and intensity. Spanning from late April to early November and extending across much of the forested regions of Canada, the season resulted in a record-breaking total area burned of approximately 15 million hectares, over seven times the historic national annual average.

Anthropogenic influences are altering fire regimes worldwide, resulting in an increase in the size and severity of wildfires. Simultaneously, throughout western North America, there is increasing recognition of the important role of Indigenous fire stewardship in shaping historical fire regimes and fire-adapted ecosystems.

Overnight fires are emerging in North America with previously unknown drivers and implications.

Ecocultural restoration involves the reciprocal repair of ecosystems and revitalization of cultural practices to enhance their mutual resilience to natural and anthropogenic disturbances and climate change stressors. Resilient ecocultural systems are adapted to retain structure and function in the face of disturbances that remain within historical ranges of severity.

Wildland fire incident commanders make wildfire response decisions within an increasingly complex socio-environmental context. Threats to human safety and property, along with public pressures and agency cultures, often lead commanders to emphasize full suppression.

Approaches to forest management have changed markedly in the Pacific Northwest in recent decades, yet legacies of past management persist on the landscape. Following clearcut logging, woody residues were typically burned to reduce future fire hazard, create planting spots, facilitate natural recruitment, and retard growth of competing vegetation.

Pyrodiversity (temporally and spatially diverse fire histories) is thought to promote biodiversity by increasing environmental heterogeneity and replicating Indigenous fire regimes, yet studies of pyrodiversity-biodiversity relationships from areas under active Indigenous fire stewardship are rare.