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Type: Journal Article
Author(s): Eric E. Knapp; Jon E. Keeley
Publication Date: 2006

Structural heterogeneity in forests of the Sierra Nevada was historically produced through variation in fire regimes and local environmental factors. The amount of heterogeneity that prescription burning can achieve might now be more limited owing to high fuel loads and increased fuel continuity. Topography, woody fuel loading, and vegetative composition were quantified in plots within replicated early and late season burn units. Two indices of fire severity were evaluated in the same plots after the burns. Scorch height ranged from 2.8 to 25.4 m in early season plots and 3.1 to 38.5 m in late season plots, whereas percentage of ground surface burned ranged from 24 to 96% in early season plots and from 47 to 100% in late season plots. Scorch height was greatest in areas with steeper slopes, higher basal area of live trees, high percentage of basal area composed of pine, and more small woody fuel. Percentage of area burned was greatest in areas with less bare ground and rock cover (more fuel continuity), steeper slopes, and units burned in the fall (lower fuel moisture). Thus topographic and biotic factors still contribute to the abundant heterogeneity in fire severity with prescribed burning, even under the current high fuel loading conditions. Burning areas with high fuel loads in early season when fuels are moister may lead to patterns of heterogeneity in fire effects that more closely approximate the expected patchiness of historical fires.

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Citation: Knapp, Eric E.; Keeley Jon E. 2006. Heterogeneity in fire severity within early season and late season prescribed burns in a mixed-conifer forest. International Journal of Wildland Fire 15(1):37-45.

Cataloging Information

  • Abies concolor
  • Abies magnifica
  • Calocedrus decurrens
  • canopy closure
  • coniferous forests
  • Cornus nuttallii
  • cover
  • FFS - Fire and Fire Surrogate Study
  • fire frequency
  • fire hazard reduction
  • fire intensity
  • fire management
  • fire severity
  • fire size
  • flame length
  • forest management
  • fuel loading
  • fuel moisture
  • heavy fuels
  • herbaceous vegetation
  • Klamath Mountains
  • landscape heterogeneity
  • late season burn
  • mineral soils
  • mosaic
  • national parks
  • old growth forests
  • overstory
  • pine basal area
  • Pinus lambertiana
  • Pinus ponderosa
  • Quercus kelloggii
  • rate of spread
  • rocky habitats
  • scorch
  • season of burn
  • season of burning
  • season of fire
  • seasonal effects
  • Sequoia
  • Sequoia National Park
  • Sequoiadendron giganteum
  • Sierra Nevada
  • Sierra Nevada mixed-conifer
  • sloping terrain
  • southern Cascades
  • statistical analysis
  • woody fuels
Tall Timbers Record Number: 19327Location Status: In-fileCall Number: Journals-IAbstract Status: Fair use, Okay, Reproduced by permission
JFSP Project Number(s):
  • 99-S-01
Record Last Modified:
Record Maintained By: FRAMES Staff (
FRAMES Record Number: 44032

This bibliographic record was either created or modified by Tall Timbers and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of Tall Timbers.