Setting and managing wildfires offers the best way to reduce catastrophic wildfires in an era of deepening drought, longer fire seasons and rising temperatures, according to Northern Arizona University researcher Pete Fule, writing in Reform Forest Fire Management.
Ironically, the vast swaths of federally owned land in northern Arizona actually offers a critical advantage in making sweeping changes in fire management, according to another study of prescribed fires, this one by researchers from Texas A&M University, published in the peer-reviewed journal Ecological Applications.
That study found the fears of lawsuits filed by private landowners severely limits the ability to use prescribed fire in areas of the country where public and private lands are widely intermingled. By contrast, the federal government owns millions of acres in northern Arizona — making it easier to deploy prescribed burns.
Finally, one more recent study hints at the dramatic changes fire management can create. That 68-year-long study in Missouri found changing fire frequencies can transform a thick oak forest into grasslands over time — or leave an open, healthy forest with little underbrush.
Managing fire in Arizona
NAU’s Fule warned that firefighters must stop rushing to put out every fire that starts. “Thinning and prescribed burning dramatically improve the chances of dry forests surviving severe fire,” said Fule.
U.S. Forest Service research scientist Malcolm North, co-author of the study, said putting out fire increases the chance of disaster. “Fire suppression works like a selective force ensuring that most wildfires are escapes that occur during extreme weather conditions in fuel-loaded forests.”
Fule noted that climate models show that the problem will only get worse in coming decades, as temperatures rise and droughts deepen.
Studies show that tree densities in northern Arizona in the past 150 years have increased from perhaps 30 per acre to more like 800 per acre across wide expanses of the ponderosa pine forests. The Forest Service spent almost a century rushing to put out fires as quickly as possible, intending to leave more trees for loggers. However, fire suppression led to a dramatic increase in tree densities at the same time overgrazing removed the grass that once carried frequent, low-intensity fires.
Lawsuits block fires
Still, the Texas study shows that fire managers in Arizona have one big advantage — huge stretches of public lands.
The study found that private land managers generally shy away from using managed fire, in large measure because of fear of liability if the fire gets out of control.
So even when lands suffer from dangerous increases in tree density and health problems linked to the exclusion of fire, land managers don’t dare turn to prescribed fire, the researchers concluded.
Legal standards vary from state to state and have a big impact on fire management. Some counties have standards that hold fire managers libel for any damage caused by an escaped fire. Others have a “simple negligence” standard, which means fire managers must simply take reasonable steps to keep the fire under control. Finally, some jurisdictions have a “gross negligence” standard, which makes fire managers vulnerable to lawsuits only if they acted with “recklessness.”
The stricter the legal standard, the fewer acres land managers burn.
In Arizona, the federal government owns most of the land and has substantial protection from lawsuits when a fire gets out of control. Moreover, forested communities like Payson, Pine, Show Low, Springerville and others are much more widely scattered and easier to protect than in other states with much of the forested land in private hands.
Crafting the forest
Finally, a University of Missouri study of the effect of fire on an oak forest demonstrated how fire dominates the whole ecosystem.
The researchers examined the 69-year record of fires in three oak forests. In one forest, fires burned through every year. In a second area, fires burned through every four years. In the third area, the forest hadn’t burned since 1949.
The forest subjected to annual burning essentially turned into a grassland. The frequent fires eventually killed the big trees and prevented any more from sprouting.
Fires every four years created an open woodland dominated by big trees — with little underbrush — a hiker’s dream.
But completely excluding fire resulted in a dense forest, with the spaces between the big trees choked with brush and saplings. Once a fire gets loose in that setting, it would create a catastrophe, the researchers concluded.