title: A review of the relationships between drought and forest fire in the United States.
abstract: The historical and presettlement relationships between drought and wildfire are well documented in North America, with forest fire occurrence and area clearly increasing in response to drought. There is also evidence that drought interacts with other controls (forest productivity, topography, fire weather, management activities) to affect fire intensity, severity, extent, and frequency. Fire regime characteristics arise across many individual fires at a variety of spatial and temporal scales, so both weather and climate - including short- and long-term droughts - are important and influence several, but not all, aspects of fire regimes. We review relationships between drought and fire regimes in United States forests, fire-related drought metrics and expected changes in fire risk, and implications for fire management under climate change. Collectively, this points to a conceptual model of fire on real landscapes: fire regimes, and how they change through time, are products of fuels and how other factors affect their availability (abundance, arrangement, continuity) and flammability (moisture, chemical composition). Climate, management, and land use all affect availability, flammability, and probability of ignition differently in different parts of North America. From a fire ecology perspective, the concept of drought varies with scale, application, scientific or management objective, and ecosystem.
authors.affiliation: DOI Alaska Climate Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Littell
authors.affiliation: USDA Forest Service Pacific Northwest Research Station, 400 N. 34th Street, Suite 201, Seattle, WA, 98103, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Peterson
authors.affiliation: USDA Forest Service Rocky Mountain Research Station, 800 East Beckwith, Missoula, MT, 59801, USA.
authors.forename: Karin L
authors.initials: KL
authors.lastname: Riley
authors.affiliation: USDA Forest Service Southern Research Station, 320 Green Street, Athens, GA, 30602, USA.
authors.forename: Yongquiang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: USDA Forest Service Rocky Mountain Research Station, 322 East Front Street, Suite 401, Boise, ID, 83702, USA.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Luce
mesh_terms: D057231:Climate Change; D055864:Droughts; D017753:Ecosystem; D005390:Fires; D065928:Forests; D014197:Trees; D014481:United States
keywords: climate change; climate variability; drought; ecological drought; fire; water balance