The importance of geography in forecasting future fire patterns under climate change

Area of Science:

• Ecology
• Climate Science
• Environmental Modeling

Background:

• Wildfire activity in California has increased in recent decades, driven by climate change factors like rising temperatures and vapor pressure deficit.
• The expanding wildland-urban interface heightens human exposure to wildfires, threatening both communities and ecosystem resilience.
• Accurate projections of future wildfire activity are crucial for disaster response, land management, and biodiversity conservation.

Purpose of the Study:

• To investigate how the geographical scale of fire models influences projections of future wildfire activity under climate change scenarios in California.
• To compare state-wide fire models with ecoregion-specific models to understand variations in climate-fire relationships across California's diverse landscapes.

Main Methods:

• Utilized a Maximum Entropy model trained on historical fire records (1981-2010), hydroclimatological variables, topographic data, and human infrastructure predictors.
• Developed and compared fire occurrence models at both the state-wide and individual ecoregion levels.
• Projected end-of-century fire patterns under various climate change scenarios using the developed models.

Main Results:

• Significant geographical variation was observed in the predictors of fire probability and future fire projections based on model boundaries.
• State-wide models showed less pronounced changes in fire activity compared to ecoregion-specific models.
• Ecoregion models, which incorporated unique local vegetation, climate, and infrastructure patterns, projected increased fire occurrence in most of the state's forested regions.

Conclusions:

• The geographical extent of fire models critically impacts the interpretation of future wildfire projections in California.
• Ecoregion-specific modeling approaches are more effective at capturing the nuanced climate-fire dynamics across California's diverse landscapes.
• Future wildfire risk assessments and management strategies should consider localized ecological and climatic conditions for greater accuracy.