Our ironic thanks to Smoky the Bear’s campaign manager, the Sierra Club, and all those well-meaning folks who have just delivered the second-largest wildfire in Arizona history. The Wallow Fire has burned more than 600 square miles of Ponderosa pine forest at this writing—and it is still burning. It still has a chance at exceeding the 732 square miles of the Chediski fire in 2002.
Hmm. The two biggest forest fires in Arizona history have both occurred within the last decade. Is there a pattern developing? You bet there is, and it is happening all across the western U.S. and has nothing to do with Climate Change. You can’t have forests in hot, dry climates without getting forest fires. Lightning and the flammability of wood and pine needles make that inevitable even aside from the human set campfire gone awry and the occasional pyromaniac. Our real choice is not no forest fires; it’s whether to have small forest fires or great big ones.
Early European visitors to the Ponderosa country found the mature pine forests so open they could drive wagons unimpeded under the majestic stands of tall trees, many of them more than 200 years old. There was little debris from dead trees and dead pine needles because lightning and native American deliberate burning had caused frequent small fires during the spring and fall dry seasons
The fuel loads on the forest floor in 1876 were very small, due to the frequent small fires. Nothing got out of hand. Dead limbs, small, overcrowded trees and the thick carpet of pine needles on the forest floor burned every few years. That precluded the massive stand-replacing fires we are seeing now.
The forests then had about 25 trees per acre, with the huge mature pines—200 to 500 years old —making up 20 percent of the stands. Young Ponderosa seedlings often burned, but more were constantly coming. Today, the average Ponderosa pine forest has 120 trees crowded onto each acre.
Unfortunately, that just increases the fuel loads that build up on the forest floor. Fuel loads in the U.S. Ponderosa forests today may be above 20 tons per acre. Much of it is the heavy humus of pine needles on the forest floor that makes the fires burn much hotter, and longer. The humus can generate the fearsome crown fires, which race over the countryside at freight-train speeds, uncontrollable by even the most aggressive firefighting methods of today.
Now, it may be too late even for the Forest Service’s preferred option of “prescription burning.” In the spring of 2002, a prescribed burn in the Bandelier National Monument in northern New Mexico escaped control and burned thousands of acres—along with part of the city of Los Alamos. The fuel loadings are so high in so many forests that “small” fires are extremely hard to arrange. Moreover, the well-meaning fans of Smokey the Bear are still suing in court to prevent the controlled burning, in the misguided belief they are “saving nature.”
Yesterday, firefighters reported that some surviving deer and elk were again grazing in the unburned parts of the forest. That was the historic pattern. The deer and elk ran away from the fire, just as Bambi’s mother did. Some fawns, unfortunately, were lost. But how many Bambi’s, Thumpers, and Flowers are perishing in a 600-square mile crown forest fire that is turning every living thing in its path into crisp, black sticks?