scholarly journals Fire Potential in the Spruce Budworm-damaged Forests of Ontario

1987 ◽  
Vol 63 (1) ◽  
pp. 8-14 ◽  
Author(s):  
B. J. Stocks

An experimental burning program was carried out in Ontario between 1978 and 1982 to document quantitatively fire behavior in balsam fir killed by spruce budworm. Forest fire potential in budworm-killed balsam fir stands was shown to be significantly higher for a number of years following stand mortality. Crown breakage and windthrow, with resultant fuel complex rearrangement and increased surface fuel loads, peaked 5-8 years after mortality. Fire potential was greatest during this period, decreased gradually as balsam fir surface fuels began to decompose and understory vegetation proliferated. Fires occurring prior to "green-up" in the spring behaved explosively with continuous crowning, high spread rates, and severe problems with downwind spot fires. Summer fires in this fuel type did not spread at all in the early years following mortality; however, sufficient woody surface fuel accumulation 4-5 years after mortality permitted summer fire spread

2010 ◽  
Vol 86 (2) ◽  
pp. 200-212 ◽  
Author(s):  
Martin E Alexander

In Canada, the importance of seasonality in forest fire danger rating associated with phenological changes in deciduous tree leaves and lesser ground vegetation has historically been taken into account by dividing the fire season into three distinct periods (i.e., spring, summer, and fall). During the mid-1980s, the developers of the Canadian Forest Fire Behavior Prediction (FBP) System did not envision that the M-2 Boreal Mixedwood – Green fuel type with 100% hardwood composition would eventually be explicitly interpreted by field users and other researchers to represent a trembling aspen (Populus tremuloides Michx.) fuel type in the summer following green-up or flushing of the overstory canopy and understory vegetation. Interest in what has become to be known as the D-2 FBP System fuel type to represent leafed-out trembling aspen stands during the summer fire season has steadily increased since. Formal recognition of such a fuel type may very well constitute an example of overextending the original basis and heuristics associated with the rate of fire spread model for the M-2 FBP System fuel type. Thus, the assumptions underlying a D-2 fuel type are explicitly restated here for the benefit of fire managers and researchers alike. Furthermore, an interim guideline is presented with respect to the threshold condition in fuel dryness necessary for surface fire spread in the D-2 fuel type to occur based on existing empirical observations garnered from experimental fires, prescribed burns and wildfires. This criterion was deduced from existing information and knowledge, and is expressed in terms of the Buildup Index (BUI) component of the Canadian Forest Fire Weather Index System. The rationale for the descriptive name assigned to the D-2 fuel type and the corresponding fuel strata characteristics are given. Improvements in the present basis of the D-2 fuel type could be realized from monitoring selected wildfires and operational prescribed fires and/or by carrying out an experimental burning study. Key words: Canadian Forest Fire Behavior Prediction System,Canadian Forest Fire Danger Rating System,Canadian Forest Fire Weather Index System,deciduous,fire behavior, fire danger, fire environment, fire hazard, fire potential, fire risk, forest flammability, fuel type, fuel moisture, green-up, hardwood, rate of fire spread.


1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.


1998 ◽  
Vol 74 (1) ◽  
pp. 50-52 ◽  
Author(s):  
C. E. Van Wagner

This article outlines the flexible semi-empirical philosophy used throughout six decades of fire research by the Canadian Forest Service, culminating in the development of the Forest Fire Behavior Prediction System. It then describes the principles involved when spread rate and fuel consumption are estimated separately to yield fire intensity, and the anomaly that has resulted from the omission of a foliar-moisture effect on crown-fire spread. Judged on its results so far, this Canadian approach has held its own against any other, and holds full promise for the future as well. Key words: forest fire behavior, Canadian FBP System, fire modelling, crown-fire theory, fire research philosophy


1996 ◽  
Vol 6 (4) ◽  
pp. 177 ◽  
Author(s):  
TL Clark ◽  
MA Jenkins ◽  
JL Coen ◽  
DR Packham

A numerical atmospheric model is coupled with a simple dry eucalyptus forest fire model to create a wildfire simulation model. This is used to show how certain atmospheric conditions can lead to commonly observed forest fire behavior. Using short line fires, simulations show that with moderate winds, the fire line interacts with the updraft ahead of it causing the fire line to curve forward into a conical shape. Other experiments show that when ambient winds change with height, a pair of rotating updrafts at the curved fire front can touch down within the fire and break up the fire line. We also demonstrate 'dynamic fingering', in which the rotating columns near the fire front intensify to tornado strength and can result in rapid and strong increases in the fire spread rate.


2007 ◽  
Vol 11 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Alexander Karpov ◽  
Henry Telitsyn ◽  
Nadezhda Efimova ◽  
Victor Berdonosov ◽  
Sergey Popovich

The approach to the implementation of a computer code, based on the geographic information system, for the forest fire behavior prediction is presented. Consecutive steps are considered, which include the formulation of fire spread mathematical model, classification of vegetation fuels using the forest inventory data, approximation of fire perimeter propagation, and overall arrangement of fire simulation code. .


2021 ◽  
Vol 496 ◽  
pp. 119408
Author(s):  
Djidjoho Julien Houndode ◽  
Cornelia Krause ◽  
Hubert Morin
Keyword(s):  

2000 ◽  
Vol 43 (S1) ◽  
pp. 104-112 ◽  
Author(s):  
Qijiang Zhu ◽  
Taizong Rong ◽  
Rui Sun

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.


1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.


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