The evidence continues to pile up — just like the tree thickets and dead wood in the forest.
Consider the outcome of two recent studies on the benefits of the kind of forest thinning projects that lie at the heart of the 4-Forests Restoration Initiative.
The economic return on thinning overgrown ponderosa pine forests may be as high as $5,000 per acre when you consider not only use of the wood products harvested but the wildfires averted, a team of economists and foresters from Northern Arizona University has concluded.
That’s probably a squishy number, considering the struggle to develop markets for the harvested brush and small trees that pose the greatest problem on millions of acres of forest in Northern Arizona.
Moreover, the full costs of crown fires remain hard to calculate. The Forest Service spends $2 billion annually fighting forest fires — a bill that has risen inexorably so that it now consumes about half of the total budget. Intense fires not only sterilize the soil, but make it so bad at absorbing water that devastating floods often follow — as Flagstaff discovered in the aftermath of the Schultz Fire.
Evidently that estimate doesn’t include the impact of thinning and controlled burns that dramatically reduce tree densities on watersheds — which may prove the biggest advantage of all when it comes to restoring healthy forests. With Arizona facing a dire water shortage in coming decades, we can ill afford to neglect thinning projects that will restore streams and put more water in reservoirs.
Finally, we must also restore fire to its role in these fire-adapted ecosystems.
That’s why we took note of a recent study on the effects of a controlled burn in Grand Canyon National Park. The 2,300-acre fire reduced fuel loads by 38 percent, seedling density by 48 percent, and sapling density by 27 percent — all without killing a single one of the big, fire-resistant trees. Please note: The overgrown forest had 50 tons of downed wood on each acre — a disaster just waiting to happen. Local controlled burns like the Verde Glen fire this week in the Payson Ranger District must play a key role in restoring our forests.
So the evidence is clear.
It’s only our resolve and wisdom that are still in doubt.