Rapid Growth of Large Forest Fires Drives the Exponential Response of Annual Forest‐Fire Area to Aridity in the Western United States

2022/03/01 by Caroline S. Juang, C. S. Juang, Park Williams +9 · 143 citations
Environmental Science · Mathematics · #Arid #Aridity index #Atmospheric sciences #Biology #Climate change #Climatology #Ecology #Environmental science #Exponential growth #Fire effects on ecosystems #Geography #Geology #Landslides and related hazards #Mathematics #Meteorology #Physical geography #Plant Water Relations and Carbon Dynamics

paper · doi:10.1029/2021gl097131

published in Geophysical Research Letters 49(5), e2021GL097131 (American Geophysical Union)

openalex publication_date 2022/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Annual forest area burned (AFAB) in the western United States (US) has increased as a positive exponential function of rising aridity in recent decades. This non-linear response has important implications for AFAB in a changing climate, yet the cause of the exponential AFAB-aridity relationship has not been given rigorous attention. We investigated the exponential AFAB-aridity relationship in western US forests using a new 1984-2019 database of fire events and 2001-2020 satellite-based records of daily fire growth. While forest-fire frequency and duration grow linearly with aridity, the exponential AFAB-aridity relationship results from the exponential growth rates of individual fires. Larger fires generally have more potential for growth due to more extensive firelines. Thus, forces that promote fire growth, such as aridification, have more potent effects on larger fires. As aridity increases linearly, the potential for growth of large fires accelerates, leading to exponential increases in AFAB.

Cited by

• Extremely large fires shape fire severity patterns across the diverse forests of British Columbia, Canada
• Hydroclimate volatility on a warming Earth
• Restoring frequent fire to dry conifer forests delays the decline of subalpine forests in the southwest United States under projected climate
• Quantifying the contribution of major carbon producers to increases in vapor pressure deficit and burned area in western US and southwestern Canadian forests
• Fire, Fuel, and Climate Interactions in Temperate Climates
• The Western United States MTBS-Interagency database of large wildfires, 1984–2024 (WUMI2024a)
• Carbon emissions from the 2023 Canadian wildfires
• Megapluvials in Southwestern North America
• Wildfire, Climate Change, Forest Resilience, and Carbon Solutions

Related

• Intensifying Fire Season Aridity Portends Ongoing Expansion of Severe Wildfire in Western US Forests
• Relationships between climate and macroscale area burned in the western United States
• Observed Impacts of Anthropogenic Climate Change on Wildfire in California
• Hydroclimatic Rebound Drives Extreme Fire in California's Non‐Forested Ecosystems
• Discovering the Trend and Patterns of Wildland Fires in USA and the Role of Climate Change