Fire regime

More Canadian forest area is expected to burn each year.

Wildland fire is an important natural disturbance in Canadian forests and plays a key role in shaping forest ecosystems. Wildland fire also affects human safety, health and property, and timber supply. Changes in the fire regime resulting from climate change can therefore have significant impacts on Canada’s forests, the forest industry and Canadians. The annual area of burned forest and the number of large (>200 hectares) fires have increased since monitoring began in Canada in 1959, and projections indicate continued increases in both in the future.

Read how the fire regime and its indicators are defined

The fire regime describes the patterns of fire seasonality, frequency, size, spatial continuity, intensity, type (e.g., crown or surface fire) and severity in a particular area or ecosystem.

For Forest Change, the fire regime includes the following indicators:

  • Annual area burned is the average surface area burned annually in Canada by fires greater than 200 hectares (ha). Changes in annual area burned were estimated using Homogeneous Fire Regime (HFR) zones. These zones represent areas where the fire regime is similar over a broad spatial scale, at least for the 1959–1999 period (see methods). Such zonation is useful in identifying areas with unusual fire regimes that would have been overlooked if fires had been aggregated according to administrative and/or ecological classifications.
  • The number of large fires is expressed as the annual number of fires greater than 200 ha that occur per units of 100,000 ha.
  • Fire seasonality is expressed as the yearly area burned for each homogeneous fire regime zone. It shows when fires actually occur. By contrast, fire weather indicators refer to weather conditions that are conducive to fire.

Trends in annual area burned (AAB) by fires >200 ha, and the number of large fires (>200 ha) per HFR zone were analyzed for the 1959–2010 time period using point version data from the Canadian Wildland Fire Information System. Caution is required when interpreting results, as small gaps in regional data availability and the possibility of unrecorded fires in low-density areas may have affected them.

Why the fire regime is important

Wildland fire regimes shape the ecosystem and affect forest resource availability and human safety, health and property.

Wildland fire is a significant natural disturbance in Canadian forests. Since 1990, wildland fires have burned an average of 2.3 million hectares (ha) of forest each year. The annual area burned and the number of large fires are primarily driven by weather conditions conducive to fire (see fire weather).

Wildland fires play a large role in shaping landscape diversity and productivity and affect the carbon flux in forest ecosystems. They determine forest resource availability and accessibility, and have an important impact on human safety, health and property. Understanding changes in the fire regime can allow for better management of forest resources and better planning for wildland fire evacuations.

What has changed

Both annual area burned and the number of large fires increased between 1959 and 2010.

The average values for both annual area burned and number of large fires increased during the period 1959–2010 (Figure 1).

Figure 1a – Trends in annual area burned (in hundred thousands of hectares) across Canada between 1959 and 2010.

Figure 1a – Trends in annual area burned (in hundred thousands of hectares) across Canada between 1959 and 2010.

Larger image [29 Kb]

Figure 1b – Graph showing trends in the number of large (>200 ha) wildland fires for the period 1959–2010.

Figure 1b – Trends in number of large fires (>200 hectares) across Canada between 1959 and 2010

Larger image [30 Kb]

 
Graph data - Figure 1a
Table listing the area burned in hundred thousands of hectares in Canada for the years 1959 to 2010.
Year Area burned (hundred thousands of hectares)
1959 26.35
1960 57.20
1961 231.01
1962 33.16
1963 15.31
1964 112.14
1965 20.03
1966 48.14
1967 55.77
1968 120.91
1969 139.30
1970 142.33
1971 191.28
1972 68.23
1973 99.91
1974 83.38
1975 79.72
1976 196.87
1977 133.19
1978 25.67
1979 330.58
1980 472.58
1981 618.57
1982 171.11
1983 195.84
1984 69.11
1985 72.67
1986 86.23
1987 101.29
1988 127.34
1989 749.27
1990 85.54
1991 145.59
1992 82.41
1993 189.07
1994 600.36
1995 623.12
1996 173.24
1997 52.45
1998 465.93
1999 163.22
2000 41.97
2001 56.34
2002 304.66
2003 131.52
2004 315.79
2005 181.19
2006 202.19
2007 174.99
2008 174.97
2009 77.66
2010 316.50
 
Graph data - Figure 1b
Table listing the number of large (>200 ha) wildland fires in Canada for the years 1959 to 2010.
Year Number of large fires
1959 156
1960 245
1961 424
1962 115
1963 119
1964 197
1965 97
1966 112
1967 293
1968 170
1969 228
1970 251
1971 312
1972 221
1973 223
1974 158
1975 175
1976 370
1977 230
1978 79
1979 254
1980 436
1981 413
1982 264
1983 310
1984 204
1985 190
1986 160
1987 270
1988 284
1989 765
1990 230
1991 289
1992 147
1993 198
1994 385
1995 435
1996 418
1997 123
1998 501
1999 270
2000 153
2001 163
2002 344
2003 385
2004 429
2005 321
2006 393
2007 252
2008 246
2009 256
2010 382

The outlook

Both annual area burned and number of large fires are expected to increase.

Projected warmer and drier conditions are expected to increase fire season length, annual area burned and the number of large fires. Most areas are expected to experience at least a 2-fold increase in annual area burned and 1.5-fold increase in the number of large fires by the end of the 21st century (Figures 2 and 3). Although highly variable across homogeneous fire regime zones, this increase in annual area burned would mainly result from a rise in fire activity during the months of June, July and August, especially for the 2041–2070 and 2071–2100 periods (Figure 4). These changes would have significant socio-economic and ecological impacts.

Set of five maps of Canada showing the average annual area burned by large fires for the reference period 1981–2010 compared to the projected annual area burned for the short term (2011–2040), medium term (2041–2070), and long term (2071–2100) using climate scenario RCP 2.6 and again, for the long term, using climate scenario RCP 8.5.

Figure 2 – Reference period (1981–2010) and projected annual area burned for the short- (2011–2040), medium- (2041–2070), and long-term (2071–2100) under the Representative Concentration Pathway (RCP)Footnote * 2.6 (rapid emissions reductions) and, for the long-term (2071–2100), under RCP 8.5 (continued emissions increases). Map units represent the Homogeneous Fire Regime (HFR) zones in Canada

Larger image [295 Kb]

Set of five maps of Canada showing the number of large forest fires for the reference period 1981–2010 compared to the projected number of large fires for the short term (2011–2040), medium term (2041–2070), and long term (2071–2100) using climate scenario RCP 2.6 and again, for the long term, using climate scenario RCP 8.5.

Figure 3 – Reference period (1981–2010) and projected number of large (>200 ha) fires for the short- (2011–2040), medium- (2041–2070), and long-term (2071–2100) under the Representative Concentration Pathway (RCP)Footnote* 2.6 (rapid emissions reductions) and, for the long-term (2071–2100), under RCP 8.5 (continued emissions increases). Map units represent the Homogeneous Fire Regime (HFR) zones in Canada

Larger image [277 Kb]

Graph showing the change in fire seasonality as expressed by the yearly area burned for Canada for the reference period (1961–1990) and the projected short term (2011–2040), medium term (2041–2070), and long term (2071–2100) using climate scenarios RCP 2.6 and 8.5.

Figure 4 – Historical (1961-1990) and projected (2011–2040, 2041–2070 and 2071–2100) fire seasonality as expressed by the yearly area burned (in million ha) in Canada under the Representative Concentration Pathway (RCP)Footnote * 2.6 (rapid emissions reductions) and 8.5 (continued emissions reductions)

Larger image [14 Kb]

 
Graph data - Figure 4
Table listing historical (1961-1990) and projected (2011-2040, 2041-2070 and 2071-2100) yearly area burned (in million ha) in Canada under the Representative Concentration Pathway (RCP) 2.6 and 8.5
  Historical Projected
Years Month   RCP 2.6 RCP
1981-2010 April 0.02 - -
May 0.32 - -
June 0.88 - -
July 1.16 - -
August 0.62 - -
September 0.22 - -
October 0.01 - -
2011-2040 April - 0.05 0.04
May - 0.46 0.42
June - 1.30 1.25
July - 2.59 2.23
August - 1.13 1.26
September - 0.23 0.24
October - 0.02 0.02
2041-2070 April - 0.07 0.06
May - 0.54 0.59
June - 1.53 2.68
July - 2.82 4.12
August - 1.30 2.73
September - 0.22 0.33
October - 0.02 0.04
2071-2100 April - 0.05 0.14
May - 0.55 1.34
June - 1.48 4.37
July - 3.09 4.78
August - 1.67 4.19
September - 0.23 1.07
October - 0.02 0.08
 
Sources and references for the fire regime and its indicators

Canadian Forest Service key contacts

Yan Boulanger, Research Scientist, Forest Ecology, Laurentian Forestry Centre
Sylvie Gauthier, Research Scientist, Forest Succession, Laurentian Forestry Centre

Adaptation tools and resources

Fire Smart Canada – helps people understand the potential of wildland fire affecting homes and communities. It includes a risk reduction program for forestry companies.

Forest Change Toolkit – a list of tools and resources for climate change adaptation

Find out more
Related Canadian Forest Service research