PARENT SESSION
Symposium #13: Fire suppression impacts in crown fire ecosystems.
Sponsored by ESA Vegetation Section
Organized by: J. E. Keeley and E. A. Johnson.
Wednesday, August 8, 2001. 8:00 AM to 12:00 PM. Lecture Hall
Evidence of fire suppression impacts on fire size and frequency in the boreal forest of Ontario.
Bridge, Simon1, 1
ABSTRACT- It is widely believed that fire suppression has been very effective at reducing both the average fire size and the average annual area burned in the boreal forest. This belief is, in part, based on several studies from Ontario that compare areas with and without aggressive fire suppression policies. However, closer examination of the data used in these studies reveals a bias in the results caused by an inability to detect small fires in areas without aggressive fire suppression policies. On the other hand, most boreal forest studies using time-since-fire distributions do not show any detectable effect of suppression on the average annual area burned. Applying time-since-fire techniques to new fire history data available for areas both with and without aggressive fire suppression policies in Ontario reveals that while there is variation between areas, there is no detectable change in the average annual area burned in any one area that can be attributed to fire suppression. The results have significant management implications for Ontario, where the determination of sustainable harvest levels is often based on the assumption that harvesting has replaced disturbance by wildfire
KEY WORDS: boreal, fire, ontario, suppression