Probability of sustained smoldering ignition for some boreal forest duff types
Document Type: Report
Author(s): Bruce D. Lawson; William H. Frandsen; Brad C. Hawkes; George N. Dalrymple
Publication Year: 1997

Cataloging Information

  • Canada
  • CFFDRS - Canadian Forest Fire Danger Rating System
  • DC - CFFDRS Drought Code
  • DMC - CFFDRS Duff Moisture Code
  • duff moisture
  • feathermoss
  • fuel moisture
  • ignition
  • ignition probability
  • smoldering
Record Maintained By:
Record Last Modified: September 8, 2020
FRAMES Record Number: 5954


Wildfires continue to threaten the forest resources of the boreal forest, as well as human life and property in Canada and the State of Alaska. There has been an increased understanding of the natural role of fire in these ecosystems, and prescribed fire is a tool being used more frequently by fire managers to maintain biodiversity. The prediction of sustained smoldering ignition is important to fire managers because of its usefulness in determining the occurrence of holdover lightning-and-person-caused fires. These holdover fires can tax fire-fighting resources; multiple fires can flare-up after ignition when more severe fire weather conditions occur. Also, when fire managers are applying fire as a landscape tool, prediction of long-term smoldering can assist in determining potential fire effects and judging how much effort will be needed to contain and extinguish the prescribed fire. The purpose of this report is to link the results of two separate research studies into simple, practical models of smoldering fire potential for use by fire managers in the boreal forests of Alaska and northwestern Canada. The first study, by Frandsen (1997), developed equations of smoldering ignition probability for various Alaska forest floor (duff) layers. Ignition probability was found to depend on duff moisture content, inorganic (ash) content, and organic bulk density. This report presents equations and graphs of smoldering ignition probability for boreal forest feather moss (Hylocomium splendens and Pluerozium scherberi), sphagnum moss (Sphagnum spp.), reindeer lichen (Cladina spp.), and white spruce (Picea glauca [Moench] Voss) duff, as dependent on daily values of DMC of DC. Practical applications of the ignition probability model are discussed.

Online Link(s):
Lawson, Bruce D.; Frandsen, William H.; Hawkes, Brad C.; Dalrymple, George N. 1997. Probability of sustained smoldering ignition for some boreal forest duff types. Forest Management Note 63. Edmonton, Alberta, Canada: Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre. 11 p.