8 - Conclusion

Summary

It would seem that boreal forest fires take place over both a large landscape scale and long time span. As ecologists, we have found these spatial and temporal scales difficult to study rigorously. We are still unsophisticated in our understanding of fire behavior and its population effects in the boreal forest. Many of our most cherished ecological ideas of fire effects are not well documented and many are simply intuitive arguments with informal observational support.

At best, we can state that on average boreal wildfires are large, infrequent, of high intensity and consume large amounts of the forest floor duff. Despite substantial evidence that the physical characteristics and moisture of wildland fuels account for more variation in fire behavior than do variations in fuel chemistry, there is a persistent desire to state that flammability (a vague term: see Hilado 1977, Mak 1988) in natural vegetation is determined by natural selection for fuel chemistry. However, boreal forest fire behavior results primarily from: a vegetation which produces a large amount of relatively fine fuels (≤ 2 cm in diameter) which decays slowly; and fire seasons which, over the life span of a tree (on average c. 50–150 years), can be expected to have at least one synoptic weather pattern which severely dries the ground fine and duff fuels, has lightning which ignites the fuel and high winds which cause high rate of fire spread and intensity. Further, the crown architecture of conifers and their low foliar moisture make crown fires possible.