Photo by Mike Newbry
One of the significant misleading ideas about wildfire is what some call the Southwest Model of Ponderosa pine. In the Southwest, wildfire among Ponderosa pine is characterized by low severity-high frequency fire, thus reducing fuel so that mature trees could survive the blazes.
This Southwest Model is regularly used by thinning/logging advocates (see Matt Arno’s fire regimes commentary, July 11) to justify “active forest management.” However, it is not appropriate for most vegetative communities outside of Ponderosa pine-dominated landscapes.
For instance, Ponderosa pine occupies only 4% of the landscape across northern Idaho and Montana; most pine acreage is on private lands.
By contrast, the majority of forest types of the Northern Rockies, including lodgepole pine, spruce-fir, aspen, larch, and sagebrush, are characterized by much longer fire intervals, often many decades to hundreds of years between significant blazes. Nearly all the larger blazes in Montana occur in these forest types.
These longer fire regimes are almost entirely controlled by climate/weather conditions. In other words, without extreme fire weather of high temperatures, drought, low humidity, and high winds, any ignitions in these plant communities tend to self-extinguish without burning more than a few acres.
For example, between 1972 and 1987, Yellowstone National Park implemented a policy of allowing backcountry blazes to burn without suppression. There were 235 wildfires during that time, and 222 of them never grew beyond a few acres, and only fifteen were larger than 100 acres. All self-extinguished without any human intervention.
Then 1988 came along and more than a million acres in and around Yellowstone burned. Was there suddenly more fuel in 1988 than in 1987 or 1986? Of course not. The difference was that in the 1970s, and early 1980 cool and moist conditions prevailed in the Rockies. But in 1988, the worst drought in Yellowstone’s history occurred, and with it, the largest fires in Park’s experience.
Climate, not fuels, drives all large fires, and “solutions” like logging misinterpret fire ecology.
Given climate change, we are seeing more extreme fire weather conditions, which is the driving force behind the large blazes across the West. Rarely mentioned by the “fire suppression” crowd is that between the 1940s and 1980s, when fire suppression was supposedly “successful,” the entire West was under a cool, moist climate due to the Pacific Decadal Oscillation. Indeed, it was so wet and cool that glaciers were growing in the mountains of the West.
Since the late 1980s (think Yellowstone in ‘88), we have seen some of the more severe droughts in over a thousand years. Drought in California, for instance, is the worst in 1,200 years. Anyone who has studied paleo climate/fire relationships can affirm that climate has always driven periods of large fires — long before there was any fire suppression, and yes, even with Indian burning.
Finally, numerous studies demonstrate the failure of thinning/prescribed burns to slow or stop wildfire burning under extreme fire weather conditions. There are plenty of examples around Montana where large blazes raced across logged landscapes, including the 2007 Jocko Lakes blaze that ran across logged Plum Creek land near Seeley Lake, the 2000 Darby Complex blazes, the Derby Fire near Big Timber, and many others I could name.
In every instance, extreme fire weather drove these and other large blazes. And much of the acreage burned had been “treated” by “active forest management,” a euphemism for logging. Hurricane-force winds drove the 1910 Big Burn that consumed 3-3.5 million acres of Idaho and Montana occurred long before there was any effective “fire suppression.”
It’s time to put to rest the myth that fire suppression and lack of logging are driving large blazes. Communities must promote home hardening and stop building in the Wildlands Urban Interface and zone lands to preclude dispersed home construction. Other presumed “solutions” like logging only enhance fire spread.
