Strawberry Valley, about 1895, has far trees and less vegetation than today.      Photos courtesy of Robert Smith, IAHS
Strawberry Valley, about 1895, has far trees and less vegetation than today. Photos courtesy of Robert Smith, IAHS

Speaking at last week’s Idyllwild Conversations meeting, Dr. Richard Minnich made it clear that he believes the Hill is still very vulnerable to another large and devastating wildfire.

Minnich, a fire ecology professor at the University of California, Riverside, has studied wildfire behavior in Southern California and in similar terrain in Baja California, Mexico.

His essential theorem is that the century-old policy of suppressing wildfires has created an ecosystem much more likely to produce big and powerful fires. In contrast, his studies in Mexico and historic records of Southern California fires suggest that natural wildfires were more prevalent, but significantly less destructive.

“We now have the emergence of very dense forests and fast-moving mega-fires — 50,000- to 100,000-acre fires — with the potential destruction of entire urban forest environments,” he warned.

Upon notification of a possible wildfire, agencies respond with initial attack. Depending upon the availability of firefighting resources, they send as much firefighting capability, from engine crews to air tankers, as possible. The result of this rapid and normally successful initial attack is that more than 90 percent of fires are extinguished before they exceed 10 acres. 

Over time, however, this human intervention in the natural ecosystem permits the accumulation of more and more understory. This highly flammable material allows fires to climb from ground level up moderate-height trees to the crowns of the largest trees. In the presence of Santa Ana winds, the ingredients for a horrendous conflagration are being mixed together.

A 1939 aerial photo (top) of the Idyllwild area shows significantly less tree coverage than the 2013 photo (above).           Photos courtesy of Dr. Richard Minnich
A 1939 aerial photo (top) of the Idyllwild area shows significantly less tree coverage than the 2013 photo (above). Photos courtesy of Dr. Richard Minnich

In effect, Minnich argues that current policy creates a Darwinian natural selection for larger and more destructive fires.

With too many trees present, a fire’s energy is greater than normal, which produces the fires seen since 2000 in Southern California, Minnich contends.

“The human weeding-out of small fires leads to cumulative fuel build-up and coarsening fuel mosaics,” Minnich said. “Nature responds with large fires in the most extreme weather.”

Based on his research, Minnich recommends a return to historic forest environments. Photographs from the late 19th century show that Southern California forests were much more open. The understory, which can abet large fires, did not exist.

“Pre-suppression, the forest was open stands with large trees and high crown bases,” he stated. “The forest floor was clean.” With fewer trees, the density approached 40 trees per acre, mostly older and taller, in Minnich’s opinion.

The basic message he brought was: “The new selective pressures transform ecosystems. One such example is the dense forest of Idyllwild. The forest and the town are doomed to destruction under current management.” But the community is not helpless or powerless, he added.

“To make Idyllwild a fire-safe urban forest, there are two compatible management strategies,” he advocated at the meeting. “First, more manual removal of biomass in town and second, planned biomass burns in surrounding wildlands.

“Everyone must buy into this strategy,” he stressed.

Last summer’s Mountain Fire occurred in perfect weather conditions. The winds were toward the east rather than like Santa Anas, toward the ocean. It burned more than 25,000 acres but did not transform into a mega-fire.

“It’s a golden opportunity to use that burn for subsequent management,” he said. Essentially, the Mountain Fire created a huge fuelbreak on the community’s southern and eastern edges.

However, except for the 1996 Bee Fire, which burned about 9,600 acres, there has been no fire west and north of Idyllwild since the later 1890s. “So Idyllwild has plenty of dense young trees, which are ladder trees, and an abundance of fuel litter,” he said.

More frequent but smaller burns, similar to the natural ecosystem in Baja California, is the model for Minnich. He advised for more controlled burns in the forest, especially from Humber Park to Saddle Junction. “We need to clear the forest floor,” he said. He recommended fire agencies burn 2 percent of the biomass annually. He specially urged broadcast burns in the Dark and Fuller canyons.

Individual property owners should be removing young trees and pruning other trees to 15 to 30 feet above the ground, he recommended, and stressed that neighbors must buy into this approach also or it won’t matter.

Minnich is not a strong believer in the value of oaks. He called them “a tremendous fire hazard because they behave like chaparral.”

Among the audience was Jim Rizor, whose family has lived in Idyllwild for decades. “We need a strategic approach, one based on science,” he said.

“We can’t wait for government to solve this problem,” he advocated. “We need to start on your property and get on the same page.”

While acknowledging the need for more abatement, Idyllwild Fire Chief Patrick Reitz responded, “One problem is the large number of absentee land owners. One reason they came here was the forest and trees. Telling them to reduce the number will be a tough sell.”

J.P. Crumrine can be reached at [email protected]