Fire regime zonation under current and future climate over eastern Canada.

Area of Science:

• Forestry and Ecology
• Climate Science
• Fire Ecology

Background:

• Forest fires are a major disturbance in Canadian ecosystems, significantly influenced by climate.
• Understanding fire regimes is crucial for biodiversity, carbon cycling, and forest management.
• Projected climate change necessitates defining homogeneous fire regime (HFR) zones to predict future impacts.

Purpose of the Study:

• To delineate current and future homogeneous fire regime (HFR) zones in eastern Canada.
• To model the relationship between historical fire regime attributes and climatic/environmental variables.
• To project how fire regimes will change under future climate scenarios.

Main Methods:

• Utilized Random Forests (RF) modeling to analyze fire regime attributes (1961-1990).
• Employed climatic normals from the Canadian Regional Climate Model (CRCM) for current and future projections.
• Delineated HFR zones for multiple future time periods (2011-2100).

Main Results:

• Projected heterogeneous responses of fire regimes across eastern Canada, with some regions experiencing minor alterations and others significant shifts.
• Predicted a 2.2-fold increase in fire frequency and a 2.4-fold increase in annual area burned.
• Anticipated a slight shift in the fire season later into the summer (5-20 days) for many areas due to increased extreme fire-weather and drought codes.

Conclusions:

• HFR zonation provides critical insights into regional fire regime variations under climate change.
• Identified specific zones with unique fire regime responses, which would be obscured by broader administrative or ecological stratifications.
• The findings are valuable for informing adaptive forest and fire management strategies in Canada.