Crown fire potential in lodgepole pine forests during the red stage of mountain pine beetle attack

Abstract

Mountain pine beetle (MPB) outbreaks within the previous 10–15 years have affected millions of hectares of lodgepole pine forests in western North America. Concerns about the influence of recent tree mortality on changes in fire behaviour amongst firefighters and fire managers have led researchers to attempt to quantify the effects on crown fire potential. In this paper we provide an up-to-date reviewand critiqueof research that has endeavoured toquantify the effect of recent MPB-caused tree mortality, during the red stage, on crown fire potential based upon quantitative descriptions of important crown and canopy fuel characteristics and simulation-based assessments of crown fire initiation and spread using operational and physics-based models. While significant progress has been made in characterizing the important variables affecting crown fire potential in recentlyattacked forests, we suggest that many of the conclusions drawn from simulation-based studies conducted to-date are suspect given the use of inappropriate and/or un-validated models. A systematic program of experimental burning, the monitoring and documentation of wildfires and prescribed fires, and better models of fuel moisture and fuel structure are urgently needed in order to properly assess crown fire potential in lodgepole pine forests recently attacked by the MPB.