Document


Title

The relative importance of fuels and weather on fire behavior in subalpine forests
Document Type: Journal Article
Author(s): W. C. Bessie ; E. A. Johnson
Publication Year: 1995

Cataloging Information

Keyword(s):
  • Alberta
  • Canada
  • coniferous forests
  • crown fires
  • distribution
  • fire intensity
  • fire management
  • fuel inventory
  • fuel loading
  • fuel moisture
  • moisture
  • Picea engelmannii
  • pine forests
  • Pinus contorta
  • Populus tremuloides
  • subalpine forests
  • wind
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 35619
Tall Timbers Record Number: 9930
TTRS Location Status: In-file
TTRS Call Number: Journals-E
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy 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 the Tall Timbers Research Station and Land Conservancy.

Description

Surface fire intensity (kilowatts per metre) and crown fire initiation were predicted using Rothermel's 1972 and Van Wagner@s 1977 fire models with fuel data from 47 upland subalpine conifer stands varying in age from 22-258 yr and 35 yr of daildata (fuel moisture and Wind speeds). Rothermel's intensity model was divided mto a fuel component variable and weather component variable, which were then used to examine the relative roles of fuel and weather on surface fire intensity (kilowatts per metre) Similar variables were defined in the crown fire initiation model of Van Wagner.Both surface fire intensity and crown fire initiation were strongly related to the weather components and weakly related to the fuel components due to much greater variability in weather than fuel, and stronger relationship to the fire behavior mechanisms for weather than for fuel. Fire intenSlty was correlated to annual area burned; large area burned years had higher fire intensity predictions than smaller area burned years. The reason for this difference was attributed directly to the weather variable frequency distribution. which was shifted towards more extreme values in years in which large areas burned. During extreme weather conditions, tbe relative importance of fuels diminishes since all stands achieve the threshold required to permit crown fire development. This is important since most of the area burned in subalpine forests has historlcallY occurred during very extreme weather (i e, drought coupled to high winds). The fire behavior relationshipS predicted in the models support the concept that forest fire behavior is determined primarily by weather variatiOn among years rather than fuel variation associated with stand age. © by the Ecological Society of America. Abstract reproduced by permission.

Online Link(s):
Citation:
Bessie, W. C., and E. A. Johnson. 1995. The relative importance of fuels and weather on fire behavior in subalpine forests. Ecology, v. 76, no. 3, p. 747-762.