ASPEN - The beetle epidemic that has killed trees on millions of acres in western North America isn't the ecological disaster it is often portrayed to be, a senior forest scientist with The Wilderness Society said Monday.
Greg Aplet of The Wilderness Society's Denver office said forests are already showing signs of coming back in ways that will make them more resilient and adaptable to a changing environment brought by climate change.
Aplet attended Friday's "Forests at Risk" conference which attracted more than 400 scientists, public land managers and conservationists to Aspen. Several scientists presented research on forest conditions and delivered a sobering assessment of what they have found.
It's understandable to walk out of such a conference where solid, accurate assessments of existing conditions are delivered and feel like our forests face a bleak future, Aplet said. He's a bit more optimistic.
"I think there's silver lining to this bark beetle epidemic," Aplet said. While it will take time, the forests will be much more diverse in both species and age once they recover, he said. Large swaths of Colorado were covered with lodgepole pine for thousands of acres upon thousands of acres. It's highly likely that spruce and fir will replace much of the dead lodgepole, he said.
Lodgepole pine forests in Colorado and southern Wyoming have been particularly devastated by the beetle infestation. Entire landscapes in Summit, Grand and Eagle counties have been wiped out, with the tree needles turning a rust color then graying before falling off.
Many areas of Colorado's mountains were ended up with trees of the same type and the same age as a legacy of the mining era, according to Aplet. Mountainsides were denuded for fuel for smelters and other mining operations. Trees were cut down, then crews went back and tore out stumps to burn those as well, he said.
In the late 1800s, large fires swept many parts of Colorado and burned the slash and unwanted timber left from the logging. The fires wiped out much of the remaining vegetation. Lodgepole pines "out-competed" many other species and essentially carpeted hillsides. Studies have shown that 80 percent of Colorado's lodgepole trees were between 80 and 120 years old before the epidemic.
(The Aspen area was also denuded of trees for mining activity starting in 1879, but it is at the southern edge of the lodgepole zone, so the species didn't cover the hillsides of Pitkin County like it did in other areas.)
In retrospect, it is easy to look back on conditions and say Colorado's forests were susceptible to disease and pests, he said, but the full magnitude wasn't realized in advance. "It caught everybody off guard," Aplet said.
The drought early last decade, which peaked in 2002, stressed trees of all types. That created conditions ripe for a scale and intensity of a mountain pine beetle epidemic never observed before, Aplet said.
Global warming exacerbates the problem. Higher temperatures expose trees in higher elevations to the insects, for example, Aplet said. And continuous higher temperatures likely mean more tree species will be vulnerable to insects and disease in coming decades.
"We might find ourselves without big trees on a landscape scale," Aplet said. That will affect everything from recreation to logging and simple aesthetic joy of driving through the mountains, he acknowledged. But he's confident the forests will bounce back, even if not in our lifetimes and maybe not in the same way as before.
"Life will find a way," Aplet said. "It just might not be the life we're used to."
Lodgepole pines have proven in past epidemics that they are resilient. This outbreak won't be the last of them in the Rockies, he said.
Even in places where it appeared the forest was "100 percent dead," signs of life are already appearing, Aplet said. Once the needles of dead lodgepole pine fell off, observers realized the surrounding forests "were a lot greener than we thought," he said. That's a combination of understory getting more exposure to elements and smaller trees flourishing.
The Wilderness Society and other environmental groups are urging a careful, thoughtful response from the U.S. Forest Service to the beetle outbreak. There is "some very real concern" about safety and protection of infrastructure from falling trees, Aplet said. There are thousands of miles of roads and trails where dead trees from the epidemic will be falling for "decades," he said.
The conservation group supports a Forest Service initiative to remove trees from falling distance of homes, roads, trails, campgrounds, power lines and other infrastructure. The timber cut for safety will keep Colorado's timber mills busy for years, he said.
The Wilderness Society is more cautious about logging proposals that aren't tied to safety and so-called salvage logging.
"There's great potential to overreact to the problem," Aplet said.
The organization supports using prescribed burns more frequently to restore forest health. The Forest Service is exploring a greater reintroduction of fire. It is currently studying use of prescribed burns and mechanical tree removal to treat about 50,000 acres of the White River National Forest surrounding the Roaring Fork Valley.