Climatic and landscape influences on fire regimes from 1984 to 2010 in the western United States
The authors examined the effect of climate, topography, vegetation, and human land use on the spatiotemporal patterns of fire occurrence, severity, and size across the western U.S. using boosted regression tree analysis.
Large fire occurrence was highly synchronous across broad spatial scales and significantly correlated to short-term climate anomalies. Specifically, precipitation anomalies 90 days prior to the fire had the strongest influence on large fire occurrence and percent high severity fire more than temperature or relative humidity. The authors suggest that short-term drought events may likely have the strongest influence on western wide fire synchrony. However despite occurring during time periods of similar short-term climate conditions, differences in fire severity and fire size were observed between areas of differing vegetation types. This is likely the result of differences in species composition and fuel amount and condition associated with longer-term climate effects. Elevation also had a strong correlation to fire occurrence and size. The authors suggest that fire is influenced by various factors at different spatiotemporal scales and that climate change will have varied effects on local and regional fire regimes.