ASPEN - Experts at the Forests at Risk conference in Aspen on Monday said they view thinning trees on large expanses of public lands as the only way to stop the increase of catastrophic wildfires afflicting the West.
Drought and higher temperatures are taking a toll at forests just about everywhere on the globe, said Craig Allen, a research biologist with the U.S. Geological Survey. He is stationed in northern New Mexico but worked on a study of climate change and forests with scientists in several other countries.
"All forest types are at risk," he said at the conference presented by the Aspen Center for Environmental Studies.
Fire season in the western U.S. already has grown by two months over the past 25 years, Allen said. Global-warming models indicate hot, dry conditions will reach a level by the 2040s and 2050s that haven't been seen in the past thousand years, he said. Forests will face unprecedented stress.
"We're not sure how the systems are going to respond," Allen said.
Ground fires that wiped out grasses and understory vegetation but spared many of the larger trees used to be the norm in North America. Overgrazing and the Forest Service's policy of fighting fires over the past century have allowed fuels to build up to unsafe levels, Allen said. That wasn't an issue during a significant part of the past 100 years because the climate was producing wet conditions. The widespread drought has made those fuels ripe for burning.
Allen said he only sees forests surviving if humans intervene to help them adapt. Forests needs to be mechanically thinned so that ground fires can be put to beneficial use and intense crown fires won't devastate large swaths of land, Allen said.
Frank Lowenstein, climate adaptation strategy leader for The Nature Conservancy, endorsed the idea of creating lower-density forests, where trees don't have to compete as much for water and light. With lower-density forests, "you won't see everything incinerated" by fires, he said.
Ethan Aumack, director of restoration programs for the Grand Canyon Trust, outlined his organization's effort to assist the U.S. Forest Service on a plan to thin trees across 1 million acres in northern Arizona. Mechanical treatment on 10,000 acres of forests at the edge of communities isn't enough to be effective in reducing fire threat, he said. The scope of work needs to be commensurate with the size of the intense fires ravaging the country, according to Aumack.
The problem is the expense. It costs about $1,000 per acre to undertake mechanical treatment of forests. At a time when the federal government is tightening its belt, it's doubtful that amount of funding will be available for forest-thinning projects, he acknowledged.
"It's well past what we as a society say we can afford," Aumack said.
Like Allen, Aumack said the logging industry must be integrated into the effort. There has to be a market for the wood they salvage to make the effort more economically feasible.
The cure was challenged as being as bad as the disease by some audience members at the conference, held at Aspen Meadows. Longtime Aspen environmentalist Connie Harvey said humans have a way of thinking they know what's best for nature, sometimes learning too late that a course of action was incorrect. She noted that the Forest Service followed a policy throughout the 1900s that all fires had to be snuffed as quickly as possible. Now we know that fires can be beneficial.
"Smokey the Bear is a very bad bear these days," Harvey said.
She said she has strong reservations about the calls for "treatment" of forests, which means chopping down trees.
Aumack acknowledged that million-acre thinning projects might not be best on all landscapes. That works at the elevation, landscape and tree types being targeted in northern Arizona, he said. But any thinning project should be given "a lot of hard thought."
Lowenstein defended thinning as a "drastic step" necessary because of the "drastic threat" created by drought and rising temperatures.
"We've set a trap for ourselves by not acting on climate change," Lowenstein said.
He acknowledged that thinning forests can be painful.
"There's risks. There's controversy, certainly," he said.
The debate comes as the White River National Forest prepares a number of fuel-reduction and wildlife-habitat-enhancement projects around the Roaring Fork Valley. The agency wants to undertake fuel reduction by mechanical treatment and prescribed fire on 162 acres of Basalt Mountain when conditions are safe.