Fire Statistics

“Smoking is one of the leading causes of statistics.”

-Fletcher Knebel, American writer

Statistics pertaining to all aspects of forest fire in the Intermountain West are available on the web (see especially National Interagency Fire Center: http://www.nifc.gov/stats/wildlandfirestats.html) One should bear in mind that statistics are not facts; statistics describe facts. The best way to insure that statistics are being used accurately and appropriately is to check the statistics against the facts, compare different sets of statistics, and know who is gathering and analyzing the data and for what purpose.

Statistics in the form of graphs and charts show at a glance the alarming changes in western fire-adapted forests–changes in forest structure; fire frequency; fire severity; acreage burned; and money spent. The figures below show that fire patterns of recent years are very different from historic patterns, indicating the need to change forest management practices.

The three figures below tell an interesting story. Taken separately, the graphs seem contradictory. Figure 1 shows fires increasing over time while figure 2 shows fires deceasing over time. The two graphs display different data: figure 1 shows hectares burned over the past 100 years; figure 2 shows frequency of fires over the past 300 years. The graphs reveal the pattern of fire suppression during the early and mid twentieth century and the sudden re-emergence of fire during the last decade.

Looking at the graphs together might lead one to conclude that fire patterns are just getting back to the normal fire patterns of the 18th and 19th centuries. Figure 3, however, shows this not to be the case. The fires occurring in recent years include more catastrophic, stand replacing fires– fires from which forests do not recover.

Figure 1. Annual area burned by wildfires in Arizona and New Mexico on all lands (state, private and federal), 1916 to 1996. The increased area burned in the late-20th century has been most commonly attributed to accumulated living and dead forest fuels since fire suppression began early in the century. However, wetter conditions since the 1970s might also be involved, particularly in ecosystems where plant productivity is ordinarily low, and grasses have increased in importance. Fine fuels, such as grasses and leaves, may be a key factor in these seasonally dry ecosystems where fuel continuity is limiting to fire spread. Expansion of non-native grasses in some parts of the Southwest may also have contributed to this pattern. Source: Swetnam, Thomas W. and J.L. Betancourt, "Mesoscale Ecological Responses to Climatic Variability in the American Southwest" http://geochange.er.usgs.gov/sw/impacts/biology/fires_SOI/ 4/10/03.

Figure 2. Number of fire-scar sites (chronologies) in the Southwest recording fire dates in each year, 1700 to 1990, out of a total of 63 sites. The decrease in recorded fires after ca. 1900, reflects livestock grazing affecting fine fuels, and subsequent fire suppression by government agencies. Source: Swetnam, Thomas W. and J.L. Betancourt, "Mesoscale Ecological Responses to Climatic Variability in the American Southwest" http://geochange.er.usgs.gov/sw/impacts/biology/fires_SOI/ 4/10/03.

Figure 3. “How serious is this situation? Simply, we cannot sustain our pine forests with the current rate of stand replacement wildfire. If the current rate of stand replacement wildfire remains the same (indicators are that the rate is increasing!), then half of the pine forest of the Coconino National Forest will be reduced to grasslands by the time the Pumpkin and Pipe fires of 2000 will again support an old growth forest. The ecological loss is staggering: in the vicinity of Flagstaff, a half dozen each of Mexican spotted owl territories and northern goshawk territories were lost or badly damaged since 1994, all in seven short years.” Source: Greater Flagstaff Forests Partnership. "Sustaining our forest." http://www.gffp.org/pine/p_essay/p_essay.htm 4/11/03

Figure 4 shows another alarming trend: billions of dollars spent on fire fighting in recent years on public lands. Investment in ecological restoration can dramatically decrease spending on fire suppression. Some old sayings are worth repeating: an ounce of prevention is worth a pound of cure.