Canadian Example
There can be considerable variability in the number of fires and area burned each year, (Figure 1). Not all fires are fully suppressed in Canada, with some fires receiving a modified response. Eight percent of the fires in 1995 received a modified response, but accounted for 60 percent of the area burned. On average, 10,000 fires burn 3 million ha annually (Figure 2), of which approximately 750 000 ha is commercial forest (an area equal to 3/4 of the annual area harvested).
Figure 1. Top ten years for area burned in Canada (hectares).
Figure 2. Annual variation of forest fire sizes and numbers 1918-1997.
Lightning is the cause of 35 percent of Canada's fires. This proportion, however, is responsible for 85 percent of the total area burned. This is largely due to the remoteness of much of Canada's forests which results in delayed detection and allows some fires to grow to a large size before control actions are taken.
Fire management is big business in Canada with over 500 million dollars spent each year. The 10-year average shows that close to 10,000 fires per year burn 2.3 million ha of forest land. Both fixed costs and suppression costs have increased dramatically over the past 25 years (Figure 3) and the trend is for further increases in the future. In addition, over 365 communities in Canada are dependent on forest resources for their livelihood.
Figure 3. Canada suppression costs, 1970-1995.
United States Example
It is not surprising in the aftermath of the extensive 1910 wildfires that public policies were developed that emphasized fire suppression programmes over prescribed fire programmes; programme emphasis that was universally accepted by society and politicians. But since 1910, a large body of scientific knowledge has developed regarding fire history, fire regimes, and fire effects; the decline in the health of ecosystems has reached alarming proportions; and large, high intensity wildfires are increasing in size since the mid-1980's (Figure 4).
Figure 4. Total wildfire hectares burned in the 11 western states on all Federal lands between 1916 and 1996.
Wildfire Occurrence and Cause in the United States
An accurate database indicating the occurrence and causes of wildfires by year is absolutely essential to the management of an effective fire programme. It is next to impossible, for example, to design specific fire prevention campaigns, if one cannot identify the causes of wildfires in a systematic way. If critical fire starting causes remain unknown, then it becomes extremely difficult to mount a significant prevention effort. Tracking fire numbers and sizes over the years also allows an organization to monitor and evaluate the performance of its various fire management programmes. In many countries, however, a thorough and accurate data base on wildfire statistics and prescribed fire statistics is almost non-existent. In fact, in one country wildfires are deliberately under reported, since reporting a damaging forest fire can be career threatening. In the United States, on the other hand, an individual would be disciplined for not accurately reporting fires that occurred. California receives the most money for fire suppression programmes of any other state, because officials there have demonstrated over the years with data that they have the most damaging fires.
At the present time federal and state agencies do not have a common system for reporting wildfires, although a uniform national system would be highly desirable. All agencies, however, maintain and publish wildfire statistics on an annual basis. The following two tables represent wildfire number and size by cause for State and Federal lands in 1995.
Statistical Cause |
Number of Wildfires |
Hectares Burned |
Lightning |
3,726 |
103,580 |
Campfire |
2,133 |
6,343 |
Smoking |
4,681 |
10,039 |
Debris burning |
36,056 |
113,072 |
Arson |
29,349 |
168,039 |
Equipment |
7,333 |
47,398 |
Railroad |
1,751 |
13,700 |
Children |
5,814 |
7,976 |
Miscellaneous |
22,675 |
65,820 |
Total |
113,518 |
535,967 |
Table 1. Number of fires and hectares burned by cause on State lands in 1995.
Statistical Cause |
Number of Wildfires |
Hectares Burned |
Lightning |
5,248 |
245,354 |
Equipment |
527 |
16,736 |
Smoking |
595 |
9,489 |
Campfire |
1,797 |
13,161 |
Debris Burning |
1,496 |
18,036 |
Railroad |
177 |
1,025 |
Arson |
2,323 |
33,416 |
Children |
746 |
1,648 |
Miscellaneous |
2,592 |
62,671 |
TOTAL |
15,501 |
401,536 |
Table 2. Number of fires and hectares burned by cause on Federal lands in 1995.
