Now that the smoke has cleared from two forest fires that ravaged the foothills of Jefferson and Larimer counties in June, the effectiveness of wildfire management practices is being questioned.
Since early last century, fire suppression has been the staple of wildfire management. But many experts believe suppression has created conditions that are ripe for catastrophic wildfires.
"Fire suppression has contributed to an increase in catastrophic fire, especially in the lower elevation ponderosa pine forests," said CU-Boulder geography Professor Tom Veblen, who has researched wildfire management in the West.
Veblen said fire suppression has actually changed the natural condition of the forest in areas below 8,500 feet. Instead of wide open meadows separating stands of pine trees, there now exits overgrown forests with plenty of fuel to burn.
"At the lower elevations where formally we had open woodlands of ponderosa pine, fire suppression has resulted in tree invasions into former grassland sites," said Veblen. "This has resulted in a very substantial change in forest structure and in fuel conditions so that at elevations right around the city of Boulder, at elevations near where the recent fire occurred near Drake, we have much denser forests than we did in the past."
But Veblen, who has researched forest fire data around Boulder as far back as the mid-1500s, contends that fire suppression isn聮t the only culprit at work here. According to Veblen, three or four times per century the region has exceptional climatic conditions that are conducive to widespread fires.
"These are years with above-average moisture availability that produce an increased growth of fine fuels, grasses, that sets up the possibility of having very widespread fires because we don聮t have any limitation in the form of lack of fuels."
Veblen聮s research also shows a strong link between these conditions and the El Ni帽o weather oscillation.
"What聮s interesting about the association of years of very widespread fire with that alternation from wet conditions to dry conditions, is that there is a strong linkage to the El Ni帽o southern oscillation," said Veblen. "And again, in this particular year, we聮re seeing an increased occurrence of fire during the late fazes of La Ni帽a following a previous El Ni帽o."
Veblen supports efforts by the U. S. Forest Service to lessen fire hazard through mechanical thinning and prescribed burns. The Forest Service already has two demonstration projects in the works.
The 2,100 acre Wineger Ridge project in Boulder County could begin this summer, while a similar project is planned in the San Isabel National Forest in Jefferson County near Deckers. Veblen also advocates the importance of having people who live in forested areas take steps to protect their property by creating a defensible protective space around their houses.