Utah is home to one of the world’s largest organisms. It takes up about 106 acres and likely weighs more than 13 million pounds. But you could drive right past it and not know it was there.
Because “Pando” doesn’t look like one living being — it looks like tens of thousands of individual trees. While the quaking aspen colony doesn’t all share the same roots, said Karen Mock, department head of Utah State University’s Quinney College of Natural Resources, each tree shares the same genetics.
Together, the stand has been regenerating itself in what Utahns now call Fishlake National Forest for thousands of years. Mock and a team of scientists only discovered it was a single organism in 2008.
In its short life as a confirmed superlative organism, Pando has weathered controversies. Its top spot as largest organism has been disputed. Its age has been vastly overestimated. Headlines have said it’s splitting into thirds. It’s been given a death sentence.
The truth is a bit muddier.
That’s Pando, named for the Latin “I spread.” It evokes Theseus’ ship paradox — is a thing still the same thing if all of its parts have been systematically replaced? It has inspired artists, scientists, forest managers and reporters since before anyone even knew what it was.
“I spend at least as much time philosophizing when I’m walking around aspen stands as I do thinking about science,” Mock said jokingly.
Pando’s immediate threats
Regardless of what exactly it is, and the caveats of scientific work, Pando is ill. In the years since another Utah State University researcher Paul Rogers showed Pando’s regeneration had slowed, groups have come together to sustain it.
That work has paid off, said Terry Holsclaw, a U.S. Forest Service silviculturist — someone who studies the growing and cultivation of trees.
“The stand of trees I would say is recovering at this point. Is all of it? No. But about 90% is,” Holsclaw said. “When silviculturists look at this stand and see its past, it’s come a long way in a short time.”
A healthy Pando would contain multi-generational suckers — the stems that spring from the colossal organism’s network of roots, said Rogers, who leads Utah State University’s Western Aspen Alliance.
Pando’s problem is that it’s comprised of too many old suckers. While it must contend with climate change and disease, its most immediate threats are deer and livestock, which eat new growth faster than Pando can replenish itself.
That’s what brought Division of Wildlife Resources staff to Fishlake National Forest in south-central Utah this July.
Wrangling deer for Pando
Wildlife division staffers stalked deer from their marked pickup trucks last month, driving back and forth along the one road in and out (and right through) Pando for several days.
Each time one spotted a deer — specifically a doe — another would fire a tranquilizer gun at it. Once down, crews trekked into the brush where it’d fallen and cinched on a GPS tracking collar. Staff hung around until the deer reawakened and stumbled away, perhaps into Pando. Then started the process all over again.
In a year, they’ll analyze the data to see how often mule deer are foraging in Pando’s aspen grove, and to what extent they’re breaking into fenced-off sections to munch on new growth.
Deer in the Midwest have acres of corn and soybean crops to feed on, but Utah’s mule deer live in a harsher environment, with fewer food options.
“They have to survive these hard winters,” said Vance Mumford, a biologist with the wildlife division. And baby aspen stems do the trick.
A herd of about 30 to 50 mule deer have settled near Fish Lake during the summers, where Utah’s largest natural mountain lake helps sustain a lush natural environment. This July, red and purple wildflowers dotted the meadows, where songbirds and woodpeckers flitted in treetops and rock squirrels and chipmunks toiled on the ground.
As Mumford explained the division’s plan, he pointed to some young aspens, barely knee-high and no thicker than a pencil.
“And you’ll notice this one here has been eaten off. The top stem, the leader, has been nipped off, probably by a deer,” he said. “And next door, right behind you there [through the fence], you see two plants that have not been nipped off, right?”
Trees within Pando’s fence line are regenerating. Those outside aren’t doing so well. Rogers’ more recent research confirms this: different parts of Pando have different ecological outcomes depending on if they’re fenced-in or not.
“Now we’re looking at how are we going to protect the rest of the clone that’s not fenced,” Mumford said.
As Mumford spoke, a doe milled around in an unfenced portion of Pando, just west of the Doctor Creek campground. They aren’t too scared of people, he said, as hunting isn’t allowed in the recreation area.
That evening, his team collared a handful of deer. Mumford wasn’t sure what exactly wildlife division staff will do once they get the data back, but there’s a few options: hazing, or scaring the deer out of the area; more fencing; perhaps even euthanizing some.
“Also keep in mind, as people, we’re a pretty short-lived, species, right? Forests are very long-lived. And so our solutions here don’t have to be immediate, right? Nature operates on a long timescale,” Mumford said, “and so we can make small adjustments as time goes on, as we gain more knowledge.”
“And sometimes,” he continued, “Mother Nature just fixes herself for whatever reason.”
Aspen trees, in particular, are known for their resilience, Mock said. They’re a “very disturbance-oriented species,” in that they regenerate well after fires or after otherwise being felled, such as with clear-cutting.
For thousands of years, Pando has gotten along all right despite predation, drought and those who doubted its existence.
When Mock set out nearly 20 years ago to do genetic testing on Pando with researchers Jennifer DeWoody, Carol A. Rowe and Valerie D. Hipkins, she was almost certain they’d find Pando wasn’t as big as it was believed to be. At the time, the only proof of Pando’s existence was aerial observations from the 1970s.
“I was expecting that would be the end of Pando,” Mock said.
Instead, it was a new beginning.
Soon after Mock’s discovery, the Forest Service began the Pando Restoration Project. While the agency had fenced part of Pando before, staff erected more fencing in 2009 and 2010, Holsclaw said. By 2013, about half the clone was behind a fence, according to a timeline by Friends of Pando, a citizen-science group.
The same year, the Forest Service partnered with the Utah Department of Natural Resources, which houses the wildlife division. State staffers and volunteers later installed deer-proof gates in lower Pando, so visitors can walk through the stand.
Friends of Pando, along with Snow College, began the Pando Photographic Survey in 2021, which details in 360 degrees more than 8,500 locations within Pando — images that can be used to monitor future changes.
The next year, Friends of Pando and Fishlake National Forest signed a contract to formalize their relationship. The Forest Service also approved a plan to install additional fencing around the the clone, as well as temporary fences around smaller suckers, decommission some roads and prevent cattle grazing within and near Pando.
Despite years of gloom, and an uncertain future, Friends of Pando executive director Lance Oditt is hopeful. He called this a “watershed moment,” because now there’s more collaboration — and interest — in Pando than ever before. That’s powerful, he said, even if everyone doesn’t agree on the best ways to sustain it.
Much of the Pando concern comes from Rogers’ research. But he doesn’t advocate for more fencing. That would make Pando into a zoo, he said, where people look in and observe as it grows unfettered by ungulates.
“And and what’s interesting, is what’s inside the zoo will be just as unnatural as what’s outside,” Rogers said.
If Pando’s problems are a microcosm for what is happening to other aspen groves across the planet (and they are), does fencing offer any applicable strategies? Could it create more problems, sending deer from this aspen colony to eat up another?
Oditt sees things differently. Fences aren’t the only strategy, but they’re proven — at a time when Pando needs all the help it can get.
“We can’t do a lot of that restoration, preservation work without the fences. And while people think they’re ugly, we can make fences beautiful” Oditt said. He encouraged Utahns to contact their representatives to get funding for those projects.
Protecting Pando is crucial, he said, because it can teach us about adversity, connectivity and reinvention.
Oditt found Pando after he overcame cancer. He planned a journey to visit America’s superlative trees. He saw California’s giant redwoods and sequoias and gnarled Great Basin bristlecone pines that had already outlived him dozens of times over — and would likely do so dozens of times again.
But something about Pando spoke to him.
“It gave me a scaffold for how a living thing reinvented itself out of adversity,” he said.
Oditt has hope for Pando, acknowledging that over its lifetime on Earth, it probably hasn’t looked quite the same as it does now. And likely wouldn’t look the same way again.
He said Friends of Pando wants to support researchers studying this organism, “but we also have to couch it within the larger ecological realities that we’re seeing. We’re coming out of a drought,” he said. “The tree, the past two years, has been lit up like Christmas.”
Pando’s legacy — whether it shrinks, dies or lives thousands more years — will be its contributions to genetic and ecological sciences and those who found larger meaning in this mega-organism. Mock believes this next generation of scientists will answer a question that’s been puzzling her for some time, about why trees like Pando grow so large.
It has influenced Rogers’ broader aspen research, important work on a species vital to biodiversity. And it’s changed the way he sees the world, and the creatures that live on it.
“This connectivity — and these ideas of how we interact with the Earth, and what’s the individual and what’s a community — have, I guess you’d say, evolved over time, and working a long time with Pando,” he said. “But I did not have these ideas at all when I started. I just started from scratch.”
Just like Pando. A flea-sized seed that grew into a colossus.
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