Event Title

Broad-Scale Characteristics and Management of Mixed-Severity Fire Regimes Across the Western US: a Working Hypothesis

Event Website

http://www.nafew2009.org/

Start Date

24-6-2009 8:40 AM

End Date

24-6-2009 9:00 AM

Description

Forests experiencing mixed-severity fire regimes are widespread across the western US, but these regimes are some of the most complex and least-studied. In contrast to predominantly low- or high-severity fire regimes, mixed-severity regimes require complex field techniques to characterize often high spatial and temporal variation in fire frequency and severity. Although empirical studies of mixed-severity fire regimes are mounting, they remain few and spatially limited. As an alternative approach, I present a broad-scale working hypothesis of the distribution and character of forests classified as mixed-severity by Landfire’s historical Fire Regime Group III (35-200 yr fire frequency and low- to mixed-severity). I also report the proportion and types of recent fuel-reduction treatments occurring in this zone. Across the West, this fire regime is predicted to occur in almost half of the forested area. The majority of these forests are in the Rocky Mountain and Pacific Northwest states, and on average at intermediate elevations and north-facing slopes. Twenty percent of this mixed-severity fire regime is predicted to occur in pinyon-juniper woodlands; Douglas-fir dominated forests and mixed-conifer forests each comprise one-fifth of this fire regime; and subalpine, ponderosa pine-dominated woodlands, and aspen forests each are less than 10%. About 40% of the total area treated under the National Fire Plan from 2004-2008 was in areas predicted to have this mixed-severity fire regime. The area treated was relatively evenly divided between mechanical (predominantly thinning) and fire (predominantly broadcast burns) treatments. Further empirical studies are greatly needed to verify the proposed distribution of mixed-severity fire regimes, and to evaluate strategies for successful restoration and fire mitigation across these diverse and widespread forest types.

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Jun 24th, 8:40 AM Jun 24th, 9:00 AM

Broad-Scale Characteristics and Management of Mixed-Severity Fire Regimes Across the Western US: a Working Hypothesis

Forests experiencing mixed-severity fire regimes are widespread across the western US, but these regimes are some of the most complex and least-studied. In contrast to predominantly low- or high-severity fire regimes, mixed-severity regimes require complex field techniques to characterize often high spatial and temporal variation in fire frequency and severity. Although empirical studies of mixed-severity fire regimes are mounting, they remain few and spatially limited. As an alternative approach, I present a broad-scale working hypothesis of the distribution and character of forests classified as mixed-severity by Landfire’s historical Fire Regime Group III (35-200 yr fire frequency and low- to mixed-severity). I also report the proportion and types of recent fuel-reduction treatments occurring in this zone. Across the West, this fire regime is predicted to occur in almost half of the forested area. The majority of these forests are in the Rocky Mountain and Pacific Northwest states, and on average at intermediate elevations and north-facing slopes. Twenty percent of this mixed-severity fire regime is predicted to occur in pinyon-juniper woodlands; Douglas-fir dominated forests and mixed-conifer forests each comprise one-fifth of this fire regime; and subalpine, ponderosa pine-dominated woodlands, and aspen forests each are less than 10%. About 40% of the total area treated under the National Fire Plan from 2004-2008 was in areas predicted to have this mixed-severity fire regime. The area treated was relatively evenly divided between mechanical (predominantly thinning) and fire (predominantly broadcast burns) treatments. Further empirical studies are greatly needed to verify the proposed distribution of mixed-severity fire regimes, and to evaluate strategies for successful restoration and fire mitigation across these diverse and widespread forest types.

http://digitalcommons.usu.edu/nafecology/sessions/mixed_fire/8