To carve an aspen tree — to take a blade to the trunk for the sake of your initials, for example — is to do harm. Harm to a being with a life expectancy much like our own: 100 years, if we’re lucky.
To leave your mark, “it may sound cool,” says Dan West, an aspen expert with the Colorado State Forest Service. “But that tree might not survive because of what you’re doing.”
A cut to the human arm is a possible portal for infection. Same for an aspen tree. Though the risk might be greater in aspen, considering “aspen are one of the most diseased and infected trees in North America,” West says.
Otherwise, yes, a wound to our body is much like a wound to Colorado’s favorite tree of autumn.
On our travels to behold the golden displays, we’ve all seen it. Gashed groves. White bark disrupted by black scars that look nothing like nature’s doing.
There’s someone’s name. There’s someone’s message that doesn’t matter. There’s some date marking what might be some romantic occasion. There’s a heart housing the names Megan and Jon.
Paul Rogers, director of the Western Aspen Alliance based at Utah State University, came by this one once. A harsh revision was made — an “X” over “Megan” and a message above: “MEGAN IS A SKANK.”
“It didn’t work out over time, their relationship, apparently,” Rogers says.
But the advocate scientist cares not for such drama. Nor do the trees care for our drama and whatever vain impulses lead us to scarring their skin.
It’s a particularly thin skin. That’s what makes aspen particularly susceptible. “Because of the thin skin,” Rogers says.
Aspen bark is not like the bark of a pine tree or Douglas fir or any other conifer. These white trunks don’t have that protective, rough shield. Maybe you’ve noticed even your fingernail can penetrate, easily breaking that green layer of chlorophyll, which is scrumptious to many creatures, including a slew of beetles.
Along with them, there are other invaders.
“Aspen have a lot of pathogens out there ready to eat them at a moment’s notice,” says Jonathan Coop, a professor of biology, environment and sustainability at Western Colorado University.
An opening in the bark is an opening for fungi. There the fungi might make a home while the aspen skin does what human skin does in defense: the bark closes itself.
“By closing that wound over, if there are any fungal spores inside, all that does is seal the fungus inside the tree,” West says. “And then the tree might end up with a canker.”
We know the pesky and painful canker sores in our mouth. Aspen trees know other cankers. The sooty-bark canker is fatal among the elderly. The cryptosphaeria canker has been found to be deadly as well.
The black canker presents itself “often with flaring,” reads a 2011 U.S. Forest Service report, which includes a photo example: a splayed trunk, as if the victim of a shotgun. Another photo attached to the report shows a cytospora canker and what appears to be red blood pouring around it.
“Because wounds are important infection courts for most of the canker pathogens, avoiding wounding is important,” the report reads. “This is a major reason why partial cutting in aspen is strongly discouraged. It is also a major reason why developing campgrounds in aspen stands is strongly discouraged in regional policy.”
But there are far bigger threats to aspen than our human tendency of cutting.
There is, for one, our tendency of baking the climate with greenhouse gases. Scientists have pointed to global warming for an influx of pests and pathogens and for this century’s sudden aspen decline, marked as an historic moment of widespread mortality.
Also, across the Rocky Mountains, there are massive swaths that “elk have been hammering winter after winter,” Coop says. And “the bigger issue is the elk are also browsing the sucker shoots,” he says, meaning the young. “They can prevent those stands from regenerating.”
It’s something Rogers at the Western Aspen Alliance has dedicated much of his professional time to. “This is the situation at Pando,” he says, referring to what is considered the largest aspen organism in Utah and anywhere else.
“If every (aspen) that comes up is getting eaten to the ground or the top is getting eaten off, it never progresses. And over time, you start to see generations drop out where you just have the mature trees and don’t have anything else to replace it. That’s the situation that many places in the West are in now.”
It’s a threat to the larger ecological balance of the region; aspen account for some of the most biodiverse forests out there, benefiting a vibrant array of plants and animals.
And “it really is a human problem,” Rogers says.
Solving it will take not only wildlife managers but owners of public and private lands, he says. He says it will take teamwork. It will take investments and sacrifices. “Management that we’re not used to,” Coop says.
As it is to solve our climate crisis, it will take caring. Caring more than we have apparently.
Why anyone would carve an aspen tree, “I have no idea,” West says. “I see it, and I’m like, ‘What in the hell?’”