The theory and use of two fire history models
Document Type: Journal Article
Author(s): Edward A. Johnson; Charles E. Van Wagner
Publication Year: 1985

Cataloging Information

  • age classes
  • Canada
  • coniferous forests
  • distribution
  • fire frequency
  • fire management
  • fire regimes
  • fire size
  • fire suppression
  • histories
  • pine forests
  • plant growth
  • post fire recovery
  • statistical analysis
Record Maintained By:
Record Last Modified: August 31, 2020
FRAMES Record Number: 33458
Tall Timbers Record Number: 7612
TTRS Location Status: In-file
TTRS Call Number: Journals-C
TTRS Abstract Status: Fair use, Okay, 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.


The objective of this paper is to explain the distributions, assumptions, interpretations, and relationships of the two compatible, stochastic models of fire history: the negative exponential and the Weibull. For each model the 'fire interval' and 'time-since-fire' distributions are given. Both models apply to homogenous stationary stochastic processes. The negative exponential states that the instantaneous fire hazard rate is constant for all stand ages. The Weibull states that the instantaneous fire hazard rate increases with stand age when the shape parameter is > 1 (the negative exponential is a special case of the Weibull when shape = 1). An empirical method is given for separating from an observed fire history distribution, the pre- and post-fire suppression distributions. Four relationships are derived from the models and defined per study region (per stand): (i) the fire cycle (average fire interval), (ii) the annual percent burned are (fire frequency), (iii) the average age of the vegetation (average prospective life-time), and (iv) the renewal rate.© National Research Council of Canada, NRC Research Press. Abstract reproduced by permission.

Online Link(s):
Johnson, E. A., and C. E. Van Wagner. 1985. The theory and use of two fire history models. Canadian Journal of Forest Research, v. 15, no. 1, p. 214-220.