Now we can hear one of the largest and most ancient living organisms on Earth whispering with the trembling of millions of leaves echoing in its roots.
The forest, made up of a single tree known as Pando (“I spread” in Latin), has 47,000 stems (all with the same DNA) sprouting from a shared root system over 100 acres (40 hectares) in Utah. Here, this lone male aspen (Trembling people) gradually grew into a whopping 6,000 metric tons of life.
After probably 12,000 years of life on Earth, this massive plant, whose tree-like stems rise up to 24 meters (80 feet), certainly has something to say. And the recordings released this year allow us to “hear” it like never before.
“The findings are tantalizing,” said Lance Audit, founder of Friends of Pando, when the project was unveiled in May.
“Although it started as art, we see huge potential for use in science. Wind converted into vibration (sound) and traveling through the root system can also reveal the inner workings of Pando’s vast hidden hydraulic system in a non-destructive manner.”
Sound artist Jeff Rice experimentally placed a hydrophone in a hollow at the base of a branch and ran it up to the tree’s roots, not expecting to hear much.
“Hydrophones don’t just need water to work,” Rice said. “They can also pick up vibrations from surfaces like roots, and when I put my headphones on I was instantly taken aback. Something was happening. There was a faint sound.’
During a thunderstorm, this sound was amplified – the device picked up an eerily low hum.
“I think you hear the sound of millions of leaves in the forest vibrating the tree and going down through the branches, down into the ground,” Rice explain when he presented his recordings at the 184th meeting of the Acoustical Society of America , as reported by The Guardian.
The hydrophone also picked up the thumps of a branch being tapped 90 feet away, although that sound was not audible in the air at that distance. This supports the theory that the Pando root system is interconnected, but a proper experimental setup would be needed to confirm that the sound did not travel through the soil.
Such common root systems are common in colonial aspens, but Pando’s size and age make it unique. While quaking aspens can be propagated by seed, they rarely grow from them because pollination is rare, as quaking aspens are usually only one sex, being clones of the same individual.
Friends of Pando invited Rice as an artist-in-residence to try to better understand this strange, enormous creature. Oditt hopes to use sound to map Pando’s tangle of roots.
“Sounds are beautiful and interesting, but from a practical standpoint, natural sounds can be used to document environmental health,” Rice said. “They are a record of local biodiversity and provide a baseline against which environmental changes can be measured.”
Rice also recorded the leaves, bark and surrounding ecosystem of Pando.
“The Friends of Pando plan to use the collected data as a basis for further studies on water movement, how branch arrays are interconnected, insect colonies and root depth, all of which we know little about today,” said Odith.
Unfortunately, this magnificent tree is deteriorating, leading researchers to worry that the days of Pando and all the forest life it supports are numbered. Human activities, including clearing and the slaughter of predators that reduce the number of herbivores, are eating away at this ancient creature.
All the more reason to listen to “The Trembling Giant” while it can still share its secrets.
The recordings were presented at the 184th meeting of the Acoustical Society of America.
An earlier version of this article was published in May 2023.