This episode of the OutThere Colorado Podcast dives into two different stories about the state's largest living organism – the aspen. First, we look at Colorado's claim of being home to the largest living aspen grove, thus largest living organism, on the planet. Next, we look at how these stunning trees are so fragile.
Hosted by Spencer McKee
Written by Seth Boster
Produced by Sam Schoenecker
[00:00:00] Whether those yellow leaves are quaking, quivering or trembling, it's hard to miss Colorado's
[00:00:08] aspen's come fall. Known far and wide for filling the centennial state mountainsides
[00:00:13] with hues of gold, there's more to this special species of tree than meets the eye.
[00:00:19] Welcome to the OutThere Colorado Podcast. I'm your host, Spencer McKee. Let's start the show.
[00:00:30] OutThere Colorado Podcast Episode
[00:00:40] This OutThere Colorado Podcast episode takes a dive into the aspen tree. First looking at how these
[00:00:46] tree groves can be considered the largest organism on the planet and then looking at the damage that's
[00:00:52] done when someone cars their initials into an aspen trunk, something that gets seen far too
[00:00:58] often on the trail. This episode was written by the talented Seth Boster and has been produced in
[00:01:04] house by Sam Sineker. We're coming to you from Colorado Springs, Colorado. This first portion
[00:01:10] of the podcast takes a look at how massive the aspen organism can get. Enjoy.
[00:01:16] OutThere Colorado Podcast Episode
[00:01:22] In 1992, a pair of University of Colorado at Boulder professors found themselves baffled.
[00:01:29] The Amaryllia babulsa, aka the humongous fungus, had been declared the world's largest organism.
[00:01:36] Michael Grant heard this over the radio. I thought, no, we can't have that, he recalls.
[00:01:42] Surely the quaking aspen was the largest. Surely the cloning creature was being ignored here,
[00:01:48] the single root system accounting for several trees.
[00:01:52] Jeffrey Mitten, a colleague of Grant's also specializing in the species, most certainly agreed.
[00:01:58] Yes, it would be hard to find a clone that covered more ground.
[00:02:02] But to be considered the largest, weight had to be considered. And some number of trees definitely
[00:02:08] outweighed this spongy fungus. The two set out to prove a point.
[00:02:14] It's not really scientific, Mitten says. Just to say, you know, mine's bigger.
[00:02:20] They pulled up handy data on a massive clone in Utah's Fish Lake National Forest,
[00:02:25] described in 1976. The clone reportedly covered 106 acres and contained an estimated 47,000
[00:02:33] stems. Imagining the clone once moving across the landscape with glaciers,
[00:02:37] the professors came to call him Pando, Latin for I spread out. And yes, Pando is a male.
[00:02:45] They wrote in the Journal of Nature, an average individual aspen shoot, which includes the
[00:02:50] stem plus leaves and branches would easily exceed 100 kilograms in mass while the accompanying
[00:02:56] root system would probably exceed 30 kilograms. So in the case of Pando, they reasoned approximately
[00:03:03] 6 million kilograms, 13 million pounds. The blue whale and giant sequoia had nothing on that,
[00:03:11] they wrote, nor did some humongous fungus. They concluded quaking aspen, the most widespread tree
[00:03:18] species in North America can now take its rightful place as the acknowledged giant among
[00:03:24] giants. And that was that, they figured, a fairly light argument. One made it in a few paragraphs.
[00:03:31] And yet within the next two or three years, Pando was in about 50 different newspapers. It was on
[00:03:36] radio programs. We got sick and tired of being interviewed about it. Pando is still all the
[00:03:41] rage to see the headlines from a recent year. The most massive organism on earth,
[00:03:46] the New York Times called him, the world's largest Forbes put it. That title is probably
[00:03:51] wrong. The now retired professors who popularized Pando are the first to say so. They maintained
[00:03:59] that the aspen is indeed the planet's biggest single organism, but the biggest clone? The
[00:04:04] previous research on Pando simply made him a convenient proxy for their quick case.
[00:04:11] So with Colorado's forests being the most aspen concentrated in the lower 48,
[00:04:16] might the biggest actually be somewhere here? It's possible, says Paul Rogers. He's a director of
[00:04:22] the Western Aspen Alliance. This is the tree's scientific clearinghouse that's based at Utah
[00:04:28] State University. There's never been a systemic search that I'm aware of for the largest aspen
[00:04:35] clone out there. He says, there's a fair chance that another one would be found at some point.
[00:04:40] However, it's sort of a needle in the haystack prospect and we just don't have a great mechanism.
[00:04:47] We don't know where to look and it would probably take a huge effort. So it boils back down to
[00:04:53] what's it worth and what's it all about? It's probably not worth the cost or manpower.
[00:04:58] Experts agree. Doesn't seem likely to be fruitful and it almost certainly is not good science,
[00:05:04] Grant says. We don't need to warn up Utah and yet, Colorado's have tried.
[00:05:11] Giebler Pass has become the unofficial contender. The 30-mile stretch west of Crestabute looks
[00:05:17] impressive all right with fall gold rolling as far as the eye can see. But, says Mitten,
[00:05:23] that doesn't mean a single aspen clone goes for miles and miles. He glances at a famous
[00:05:29] John Fielder photo, perhaps one that contributed to Kebler's reputation. The shark-tea-flag promontory
[00:05:35] known as the Dykes scrapes the sky above a multicolored canopy, different shades of green,
[00:05:41] yellow, orange and red all clustered at different heights, all growing seemingly as separate
[00:05:47] brothers and sisters. I suspect these are different clones, Mitten says. But that's just one
[00:05:53] snapshot of an immense forest. Could a mighty clone spring elsewhere on the pass? Or perhaps more
[00:06:00] likely elsewhere in the state? The question is likely to linger with more pressing matters
[00:06:06] facing aspen. One is a phenomenon known as sudden aspen decline. A thin shield of bark
[00:06:13] has always made stands susceptible to parasites and disease. But the US Forest Service reports
[00:06:20] that in this century, whole swaths have been observed healthy one year, dead and dying the next.
[00:06:26] The agency suspects warmer temperatures are making the trees more stressed and more vulnerable.
[00:06:32] Generally speaking, they're not very well adapted to drought and long-term drought conditions,
[00:06:37] says Jim Kravitz with the Aspen Center for Environmental Studies.
[00:06:42] Man-made climate change is seen as a grim factor, but there are others, Rogers explains.
[00:06:48] Other factors causing the death of the globe's largest known organism.
[00:06:53] Pando is the victim too of mismanagement, Rogers determined in a study last year.
[00:06:59] Where hunters and predators once diminished them, deer have rampantly chomped away saplings.
[00:07:04] Cattle have been allowed to graze further trampling the clone's attempt at regeneration.
[00:07:09] The result? A village without youth for the future.
[00:07:13] It's been around a long time and now it's crashing down on our watch,
[00:07:17] Rogers says. And that hits me right in the chest. That's the message.
[00:07:21] This thing survived for a long time and then we humans at large
[00:07:24] start fiddling around and now it's kind of unraveling. And that, he says, is what matters.
[00:07:42] This next portion of the podcast takes a look at what happens when someone decides to carve their
[00:07:47] initials into an Aspen tree trunk, something that is unfortunately a common sight noticed by leaf
[00:07:52] fevers around the state. For starters, don't do this. And here's a little bit about why you
[00:07:57] shouldn't. Enjoy.
[00:07:59] To carve an Aspen tree, to take a blade to the trunk for the sake of your own initials, for example,
[00:08:14] is to do harm. Harm to a being with a life expectancy, much like our own 100 years if we're
[00:08:20] lucky. To leave your mark, it may sound cool, says Dan West, an Aspen expert with the
[00:08:26] Colorado State Forest Service. But that tree might not survive because of what you're doing.
[00:08:33] A cut to the human arm is a possible portal for infection, same for an Aspen tree. Though
[00:08:39] the risk might be greater in Aspen, considering Aspen are one of the most diseased and infected
[00:08:44] trees in North America, West says. Otherwise, yes, a wound to our body is much like a wound
[00:08:51] to Colorado's favorite tree of autumn. On our travels to behold the golden displays,
[00:08:55] we've seen it all, gashed groves, white bark disrupted by black scars that look nothing
[00:09:01] like nature's doing. There's someone's name, there's someone's message that doesn't matter.
[00:09:07] There's some date marking what might be some romantic occasion. There's a heart housing
[00:09:12] names with Megan and John. Paul Rogers, director of the Western Aspen Alliance based at
[00:09:19] Utah State University, came by this once. A harsh revision was made in X over the name
[00:09:25] Megan with the message above it. Megan is a, and then a nasty little word.
[00:09:32] It didn't work out over time. Their relationship apparently, Rogers says. But the advocate
[00:09:38] scientist cares not for such drama nor do the trees care for our drama and whatever
[00:09:44] vein impulses us to lead to scarring their skin. It's a particularly thin skin. That's what makes
[00:09:50] Aspen so susceptible because of their thin skin, Rogers says. Aspen bark is not like the bark
[00:09:57] of a pine tree or Douglas fir or any other conifer. These white trunks don't have that
[00:10:03] protective rough shield. Maybe you've noticed even your fingernail can easily penetrate
[00:10:09] the tree trunk, easily breaking that green layer of chlorophyll which is scrumptious to many creatures
[00:10:15] including a slew of beetles. Along with them there are other invaders. Aspen's have a lot of pathogens
[00:10:21] out there ready to eat them at a moment's notice says Jonathan Koop, a professor of biology,
[00:10:26] environment and sustainability at Western Colorado University. An opening in the bark is an opening
[00:10:32] for fungi. There the fungi might make a home while the Aspen skin does what the human
[00:10:38] skin does in defense. The bark closes itself. By closing that wound over if there are any
[00:10:45] fungal spores inside all that does is seal the fungus inside the tree, West says and then the
[00:10:50] tree might end up with a canker. We all know the pesky and painful canker scores in our mouth.
[00:10:56] Aspen trees no other cankers. The sooty bark canker is fatal among the elderly. The
[00:11:03] cryptosphera canker has also been found to be deadly as well. The black canker presents itself
[00:11:10] often with flaring reads a 2011 US Forest Service report which includes a photo example
[00:11:16] displayed trunk as if the victim of a shotgun wound. Another photo attached to the report
[00:11:22] shows a cytosporic canker and what appears to be red blood pouring around it.
[00:11:28] Because wounds are important infection courts for most of the canker pathogens, avoiding
[00:11:34] wounding is important. The report reads this is a major reason why partial cutting in Aspen
[00:11:39] is strongly discouraged. It is also a major reason why developing campgrounds in Aspen stands
[00:11:45] is strongly discouraged in regional policy. But there are far bigger threats to Aspen
[00:11:51] than our human tendency of cutting. There is for one our tendency of baking the climate
[00:11:56] with greenhouse gases. Scientists have pointed to global warming for an influx of pests and pathogens
[00:12:02] and for this century's sudden Aspen decline marked as an historic moment of widespread
[00:12:07] mortality. Also across the Rocky Mountains there are massive swaths that elk have been
[00:12:13] hammering winter after winter, Koop says. And the bigger issue is the elk are also browsing
[00:12:19] the sucker roots he says meaning the young they can prevent these stands from regenerating.
[00:12:25] It's something Rogers at the Western Aspen Alliance has dedicated much of his professional time to.
[00:12:30] This is a situation with Pando, he says referring to what is considered the largest Aspen organism
[00:12:35] in Utah and anywhere else. If every Aspen that comes up is getting eaten to the ground or
[00:12:42] the top is getting eaten off it never progresses and over time you start seeing
[00:12:46] generations drop out where you just have mature trees and don't have anything else
[00:12:51] to replace it. That's the situation that many places in the West are in right now.
[00:12:57] It's a threat to the larger ecological balance of the region. Aspen account for some of the most
[00:13:02] biodiverse forests out there benefiting a vibrant array of plants and animals.
[00:13:08] And it's really a human problem, Rogers says. Solving it will not only take wildlife managers
[00:13:14] but owners of public and private lands he says. He says it will take teamwork,
[00:13:19] it will take investments and sacrifices, management that we're not used to.
[00:13:24] As it is to solve our climate crisis it will take caring, caring more than we have apparently.
[00:13:30] Why anyone would carve into an Aspen tree? I have no idea. West says I see it and I'm like
[00:13:36] what the hell.
[00:13:37] Thanks so much for tuning into this episode of the Out There Colorado podcast.
[00:13:49] Look forward to more episodes soon to come, generally on a weekly basis. This episode was
[00:13:53] written by the talented Seth Boster and has been produced in-house by Sam Sineker.
[00:13:58] I'm your host, Spencer McKee. Until next time, I'm signing off from the beautiful
[00:14:02] city of Colorado Springs, Colorado. Keep getting out there, Colorado.
[00:14:32] you