Summit County: What will the future forest look like?
summit daily news
When it comes to what Summit County’s forests, devastated in the short term by the mountain pine beetle, will look like, no one really knows.
It’s not the most satisfying answer, but it’s the truth, said Kristen Pelz, graduate student at Colorado State University’s Department of Forest and Rangeland Stewardship. She presented at last week’s Forest Health Task Force luncheon in Breckenridge.
For her master’s degree – work that’s continuing into her Ph.D. work – she looked at areas in the White River National Forest that were affected by a lesser pine beetle outbreak in the 1980s.
“(The 1980s outbreak) was not as intense at the landscape level,” Pelz said, though some areas were hit severely by the beetle.
Aside from questions about what was different between then and now and what’s causing the extent of the damage 30 years later – such as questions of climate change, snowpack and more – Pelz more sought to find out how the forests are regenerating.
And they are.
“There are a lot of down logs, but there are trees growing,” Pelz said. “There’s definitely a forest that will regenerate.”
Her work is backed up by a future forest modeling exercise Forest Service regional vegetation ecologist Claudia Regan did years ago. The model largely matches what Pelz found in the field.
But when Pelz tried to identify whether the new forest is predominantly lodgepole pine, spruce, aspen or another species, her findings varied. Each area she looked at behaved differently.
It depends on soil, she said, as well as water, light, existing undergrowth and more.
Regan added that it’s tough to pinpoint what the forest looks like because of its intensely varied physiology.
“Understanding the future forest condition has a lot of variable on whether the seed germinates and whether trees grow,” she said. “There’s not a simple answer.”
In some areas, where some lodgepole had survived the attack, the trees “really grew,” Pelz said. “They were able to grow a lot after the (other) trees fell.”
That’s because the canopy opens and the already growing seedling has less competition for nutrients.
But where mixed conifer seedlings had already sprouted, the lodgepole wasn’t able to come back. Lodgepole pine are more shade-resistant than other trees, so the other species are able to grow and use nutrients.
And in other areas, for reasons Pelz couldn’t explain, meadows have formed. Presumably, it’s because the grasses are competing for tree seed germination, and the grasses seed first.
“Much of it had already started prior to the outbreak. Once light came through, they were able to really grow,” she said. Often, it’s shade-tolerant species that sprout up.
The bottom line, Pelz said, is more diversity in species once this outbreak calms, trees are removed or simply fall down and revegetation begins.
And, it’s all part of a natural cycle – the mountain pine beetle is part of the ecosystem and has come and gone before. There may be questions about whether the current outbreak is an indicator of climate change, or whether human management played a role, or how other disturbances were part of the equation, but in general, the process is part of the forest’s existence.
“Trees don’t live forever,” Regan said. “They just don’t. It won’t always be green in a given place.”
The problem that arises with a landscape-level impact of the mountain pine beetle is the sheer amount of fallen trees, Pelz said, which not only creates a layer of timber through which new plant life can’t penetrate, but it could bring any wildfire closer to the forest floor – where it will burn hot and potentially sterilize the soil or make it hydrophobic.
White River National Forest forester Cary Green said the High Country forests aren’t currently at any more risk for damaging wildfire than a green forest, but the danger is rising as the trees are starting to fall.
While there’s still time in the bank, he and others are discussing what the future forest can and should look like, and how to achieve it for the long term while balancing limited resources and potential effects to human safety and property.
Support Local Journalism
Support Local Journalism
As a Summit Daily News reader, you make our work possible.
Your donation will be used exclusively to support quality, local journalism.
If you don't follow the rules, your comment may be deleted.
User Legend: Moderator Trusted User