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Type: Journal Article
Author(s): Eric E. Knapp; Jon E. Keeley; Elizabeth A. Ballenger; Teresa J. Brennan
Publication Date: 2005

Fire exclusion has led to an unnatural accumulation and greater spatial continuity of organic material on the ground in many forests. This material serves both as potential fuel for forest fires and habitat for a large array of forest species. Managers must balance fuel reduction to reduce wildfire hazard with fuel retention targets to maintain other forest functions. This study reports fuel consumption and changes to coarse woody debris attributes with prescribed burns ignited under different fuel moisture conditions. Replicated early season burn, late season burn, and unburned control plots were established in old-growth mixed conifer forest in Sequoia National Park that had not experienced fire for more than 120 years. Early season burns were ignited during June 2002 when fuels were relatively moist, and late season burns were ignited during September/October 2001 when fuels were dry. Fuel loading and coarse woody debris abundance, cover, volume, and mass were evaluated prior to and after the burns. While both types of burns reduced fuel loading, early season burns consumed significantly less of the total dead and down organic matter than late season burns (67% versus 88%). This difference in fuel consumption between burning treatments was significant for most all woody fuel components evaluated, plus the litter and duff layers. Many logs were not entirely consumed-therefore the number of logs was not significantly changed by fire - but burning did reduce log length, cover, volume, and mass. Log cover, volume, and mass were reduced to a lesser extent by early season burns than late season burns, as a result of higher wood moisture levels. Early season burns also spread over less of the ground surface within the burn perimeter (73%) than late season burns (88%), and were significantly patchier. Organic material remaining after a fire can dam sediments and reduce erosion, while unburned patches may help mitigate the impact of fire on fire-sensitive species by creating refugia from which these species can recolonize burned areas. Early season burns may be an effective means of moderating potential ecosystem damage when treating heavy and/or continuous fuels resulting from long periods of fire exclusion, if burning during this season is not detrimental to other forest functions.

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Link to this document (395 KB; full text; pdf)
Citation: Knapp, Eric E.; Keeley, Jon E.; Ballenger, Elizabeth A.; Brennan, Teresa J. 2005. Fuel reduction and coarse woody debris dynamics with early season and late season prescribed fire in a Sierra Nevada mixed conifer forest. Forest Ecology and Management 208(1-3):383-397.

Cataloging Information

  • burning season
  • Calocedrus decurrens
  • conifer forest
  • coniferous forests
  • Cornus nuttallii
  • CWD - coarse woody debris
  • dendrochronology
  • duff
  • ecosystem dynamics
  • FFS - Fire and Fire Surrogate Study
  • fire exclusion
  • fire hazard reduction
  • fire management
  • fire scar analysis
  • fire size
  • forest management
  • fuel accumulation
  • fuel loading
  • fuel management
  • fuel moisture
  • fuel reduction
  • fuel treatment
  • heavy fuels
  • Jeffrey pine
  • litter
  • national parks
  • old-growth forests
  • organic matter
  • Pinus jeffreyi
  • Pinus lambertiana
  • Pinus ponderosa
  • ponderosa pine
  • Quercus kelloggii
  • season of fire
  • Sequoia National Park
  • Sierra Nevada
  • Sierra Nevada mixed-conifer
  • size classes
  • statistical analysis
  • surface fuels
  • woody fuels
Tall Timbers Record Number: 19425Location Status: In-fileCall Number: Fire FileAbstract Status: Okay, Fair use, Reproduced by permission
Record Last Modified:
Record Maintained By: FRAMES Staff (
FRAMES Record Number: 4479

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.