Resilient lodgepole may help Summit forests recover from pine beetle
Fire, disease, logging — these are mortal enemies to most trees. Yet the lodgepole pine seems to thrive after disaster, and that is a bit of good news for Summit forests devastated by the mountain pine beetle.
Matt Schlitz, a forester with the Colorado State Forest Service, gave a presentation Tuesday to the Forest Health Task Force about the lodgepole’s resiliency. The task force is a collaborative program that brings together various forest-related government agencies and nonprofits to promote and educate about forest health.
Schlitz, who works out of the CSFS’s Granby field office, demonstrated the lodgepole’s knack for regrowth with a case study of the forest in and around the old ghost town of Arrow, located just north of Winter Park.
Back at the turn of the 20th century, Schlitz explained, Arrow was a bustling logging and tourist town in Grand County after the Moffat railroad came through over Rollins pass in 1905. At its height, Arrow (previously known as Arrowhead) was the largest town in Grand, with a population of 200.
By 1920, much of the surrounding forest had been cut and cleared for lumber. That year, a debt-burdened saloon owner set his establishment on fire as part of an ill-conceived insurance scheme. The fire spread and the entire town and adjoining hillside forest burned to the ground. People abandoned Arrow, and nature slowly reclaimed the hill.
When Schlitz looked over Google Earth images of the area in 2005, he found the area covered in dense, green, mature forest. Then in 2007, the mountain pine beetle epidemic hit, impacting 3.4 million acres of forestland in Colorado, including most of the lodgepole pine trees around what used to be Arrow.
Denver Water Board owns the land in the area, and called on CSFS to conduct salvage and management operations for beetle-killed pine. In 2010, all of the dead pine was harvested and cleared. In a series of photographs, Schlitz showed the progress of regeneration in the area.
“We returned to that site in 2013, and a fairly large number of lodgepole pine seedlings had been established,” Schlitz said. “They were only about 6 inches to a foot high.”
However, by 2016, Schlitz said the area saw “a surprising amount” of lodgepole growth. “Within a matter of three years, they’ve grown to 21/2 feet. Young, vigorous lodgepole.”
How did that rapid regrowth happen? Schlitz said that it was all part of the lodgepole’s programming.
“All those large cuts a few years ago (were) replicating disturbances, such as fire,” he said.
The lodgepole pinecone is designed to be “activated” by fire or heat, and lays dormant until such disturbances occur. When they do, the cones release seeds that take root and grow quickly. Thus, devastation is actually the spur for the lodgepole, and the ashen and bare patches across Summit might see significant regeneration for many years to come.
“You might not see it now, but all over Summit there are these little seedlings growing, thousands in an acre. This is new forest that can take hold and become a real dense area of growth for the next 100 to 200 years,” Schlitz said.
Howard Hallman, director of the Forest Health Task Force, cautioned that climate change and other factors, such as geography, could change the makeup of the forest and the trees growing in them.
“Say you have a southern-facing hillside that’s drier and warmer. It might not come back as forest at all; it might come back as sage brush or some other tree species.”
On the other hand, a mix of trees more adapted to the environment might have the opposite effect, giving rise to stronger, more diverse and more resilient forests. Hallman said that the U.S. Forest Service and CSFS have been trying to introduce diversity in tree species for this very reason.
“The more species that are in the area, the harder it is for the forest to be wiped out by any one kind of disease, like the mountain pine beetle,” he said.
Hallman stressed the need for more resources and more research to protect Summit’s forests.
“Particularly in Summit County,” he said, “where the danger of wildfire is increasing with higher temperature and drier conditions, we can’t afford to be passive. We need to be proactive with the diversity of species and management plans.”