Forests occupy approximately 40 percent of the vastCanadian landscape, cover approximately 417 million hectares, and constitute ~10percent of the global forest resource. Of the total forest area, approximately57 percent (~235 million hectares) is considered commercial forest, managed fora variety of purposes, including timber production. Approximately 1 millionhectares are harvested each year. Canadas non-commercial forest, situated tothe north, is made up primarily of open forests comprising natural areas ofsmall trees, shrubs and muskeg, and is rich in biodiversity.
Fire is natural to Canadian forests, particularly in theboreal zone (Canada has 30 percent of the worlds boreal forest) which hasbeen shaped by periodic wildfire for millennia, to the point that fire isessential to boreal ecosystem structure and function. Crown fires dominate inthe Canadian boreal zone, with the result that tree species have adapted tolethal fire, regenerating from seed released soon after the passage of the fire.Large contiguous areas of crown fire-prone even-aged forest dominate the boreallandscape.
For much of the first half of the 20th centuryCanadian fire management practices were strongly influenced by Europeanapproaches to forest management. Fire was seen as an enemy and something to beeliminated from the forest whenever and wherever possible. Over time there hasbeen a gradual recognition that eliminating fire in Canadian forests is neithereconomically possible or ecologically desirable. Modern fire managementprogrammes in Canada now balance the protection of human lives and property withan awareness and consideration of the natural ecological role of fire.
Canadian Forest Fire Statistics
Forest fire statistics have been archived in Canada since1920 and, within limits, this extensive record permits a general analysis oftrends in this country (Figure 1). However, it is recognized that the Canadianfire record prior to the early 1970s is incomplete, as various regions of thecountry (particularly in the north) were not consistently monitored during thisperiod. For example, the Yukon and Northwest Territories have only reportedburned areas since 1946, while the province of Newfoundland began reporting in1947. It is expected that incomplete records are much more of a problem prior to1950, and the advent of satellite coverage in the early 1970s has resulted in avirtually complete record over the past 3 decades.
Figure 1.Number of fires and area burned in Canada,1920-1999.
Keeping these uncertainties in mind, fire occurrence inCanada has increased steadily (primarily due to increasing population pressuresand forest use) to average close to 9000 fires annually since 1980. The averageannual area burned has increased post-1970, to an average of 2.8 millionhectares during the 1990s. Annual area burned is highly episodic and can vary byan order of magnitude (e.g., from 0.76 million hectares in 1984 to 7.28 millionhectares in 1989).
Regional-scale lightning fire occurrence variessignificantly across Canada, but on average lightning accounts for 35 percent offires nationally. However, lightning fires account for ~85 percent of the totalarea burned, largely due to the fact that lightning fires occur randomly andoften in large numbers, presenting access problems not normally associated withhuman-caused fires. The result is that lightning fires generally grow larger, asdetection and subsequent initial attack is often delayed.
There are two primary reasons why the impact of fires onthe Canadian landscape varies significantly at a regional scale:
1. Extreme fire weather/fire danger conditions occur in the boreal forestzone of west central Canada.
2. Fires occurring in remote or unmanaged forest zones are oftenallowed to burn in a natural manner.
Sophisticated fire management programmes in all Canadianprovinces and territories are largely successful in controlling the vastmajority of forest fires at an early stage, particularly in the intensivelyprotected forest zone. As a result, only ~3 percent of the fires in Canada growlarger than 200 hectares in size, but these fires account for ~97 percent of thearea burned nationally. A large majority of the larger fires occur in thelimited suppression or modified suppression zones of Ontario,Manitoba, Saskatchewan, and the Yukon and Northwest Territories regionswhere unmerchantable timber values permit more natural fire regimes. Anexamination of the spatial distribution of large Canadian fires (Figure 2) showsby far the greatest fire activity and area burned occur in the boreal region ofwest-central Canada. This is due to a combination of fire-prone ecosystems,extreme fire weather (a continental climate), frequent lightning activity, andreduced levels of protection in the region.
Figure 2.Greatest fire activity and area burned occur in boreal region of west centralCanada.
The preponderance of large fire activity in west-centralCanada is also reflected in Figure 3. The shortest fire cycles occur in thisregion, particularly in the boreal shield areas of northwestern Ontario,northern Manitoba and Saskatchewan, and the Northwest Territories.
Figure 3. Typical fire cycles in Canada.
Canadian Fire Management Capacity
In Canada the ten provinces and three territories own theland and are responsible for all land management activities, including forestand fire management. The federal government, through Parks Canada, operates afire management programme in a number of national parks across the country. Allfire management agencies in Canada are autonomous and have unique organizationalstructures and approaches.
Fire suppression resources in Canada are shared asrequired between agencies under the Canadian Interagency Mutual Aid ResourcesSharing (MARS) Agreement, and the Canadian Interagency Forest Fire Centre(CIFFC) in Manitoba coordinates the sharing and movement of resources. Canadaalso has a reciprocal agreement with the United States that provides for thefast movement of resources between the two countries during severe fireincidents. Canada has a fleet of fifty Canadair CL-215/415 aircraft. Theseaircraft are operated by the provincial/territorial governments, and werepurchased as a cooperative federal/provincial undertaking.
Fire management is a costly undertaking in Canada. Bothfixed and variable costs have risen dramatically over the past 25 years, andthis trend is expected to continue. At the present time fire management costsare averaging $500 million CDN annually.
Forest Fire Research in Canada
Canada has conducted a national forest fire researchprogramme for the past 75 years. Under the auspices of the federal forestryagency (currently the Canadian Forest Service), this programme has traditionallyaddressed major and topical fire management issues, and has evolved in concertwith, and in support of, changing fire management practices nationally. Althoughfire research activities are carried out at academic and provincial/territorialinstitutions in Canada, research at the federal government level has beendominant, providing the much-needed stability and continuity required to build arelevant and adaptable research programme. Despite fluctuating levels of fundingsupport and the associated continual opening/closing of research establishments,fire research at the federal level in Canada has endured, building on previousresearch and producing leading-edge scientific solutions to Canadian firemanagement problems. A prime example is the Canadian Forest Fire Danger RatingSystem (CFFDRS), developed over a half-century and completed in 1989, now in usethroughout Canada and in a number of countries internationally. Canada has alsobeen a leader in the development of computerized fire management decisionsupport systems that have revolutionized operational fire management in Canada,and have been exported extensively.
At the present time the Canadian Forest Service fireresearch programme has a complement of 25 (16 professionals), located primarilyat the Northern Forestry Centre in Alberta and the Great Lakes Forestry Centrein Ontario, with smaller complements at the Pacific Forestry Centre in BritishColumbia and the Laurentian Forestry Centre in Quebec. Research is primarilyfocused in four areas: fire behaviour/fire danger, fire management systems, fireecology, and fire and global change.
Fire management in Canada has evolved in response toregional and national priorities over the past century. While these pressuresare expected to continue, larger international environmental issues are becomingincreasingly important. Awareness of the potential impacts of climate change onforest fire regimes at northern latitudes, particularly the circumpolar borealzone, are raising international concerns over the effects of increasing fireactivity on the global carbon budget. Any movement towards warmer and drierspring/summer weather in Canada can be expected to translate directly to morefrequent and severe fire activity, with resulting impacts on the global carbonbudget. In a post-Kyoto world, Canadian fire management agencies must deal withthe impact of increased fire activity on the Canadian forest resource, while atthe same time recognizing, and responding to, international concerns over theglobal implications of changing fire regimes in the carbon-rich boreal zone.
Author and contact address:
Brian J. Stocks Senior Research Scientist Forest Fire and Global Change Canadian Forest Service Natural Resources Canada 1219 Queen Street East Sault Ste. Marie, Ontario P6A2E5 CANADA Fax: ++1-705-541-5701 Tel: ++1-705-541-5568 e-mail: email@example.com