Scientists Capture Eerie Rumbles From Pando, The World's Largest Living Organism

Pando — a vast clonal stand of quaking aspen in Utah long considered the world's largest living organism by mass — has yielded audible vibrations recorded by a hydrophone placed toward its root zone. The recordings reveal low, rumbling sounds and subtle knocks that suggest vibrations travel through the grove's shared structure, offering a potential non-destructive way to probe the tree's hidden systems.

Background

Pando (Latin for "I spread") is a single clonal quaking aspen (Populus tremuloides) colony that covers roughly 100 acres (40 hectares). It produces about 47,000 stems that share one extensive root system. Estimated at around 6,000 metric tons and possibly up to 12,000 years old, Pando's stems can reach roughly 24 metres (80 feet) tall, making it unique in size and antiquity.

How the Sounds Were Captured

Sound artist and researcher Jeff Rice inserted a hydrophone down a hollow at the base of a branch and guided it toward the root zone. "Hydrophones don't just need water to work," Rice said. "They can pick up vibrations from surfaces like roots as well, and when I put on my headphones, I was instantly surprised. Something was happening. There was a faint sound." During a thunderstorm, those faint signals swelled into a deep rumble.

Key Findings

The hydrophone recorded:

• Low-frequency rumbling consistent with the collective vibration of millions of leaves and stems driven by wind.
• Localized knocks and thumps — including a recorded tap on a branch roughly 90 feet (≈27 metres) away — that were not audible through the air at that distance but registered on the device.

"The findings are tantalizing," said Lance Oditt, founder of Friends of Pando. "While it started as art, we see enormous potential for use in science. Wind, converted to vibration (sound) and traveling the root system, could also reveal the inner workings of Pando's vast hidden hydraulic system in a non-destructive manner."

Scientific Value and Caveats

Rice presented the recordings at the 184th Meeting of the Acoustical Society of America and suggested that acoustic monitoring might help map root connections, document water movement and provide a baseline of ecosystem health. However, researchers note that controlled experiments are still required to confirm whether the vibrations travel primarily through the interconnected root network or through the soil itself.

Conservation Concerns

Pando is in decline. Human activities — including land clearing and the removal of predators that keep herbivore populations in check — have contributed to heavy browsing and reduced regeneration. Conservationists say the more we learn about Pando's internal dynamics, the better we can protect this ancient and irreplaceable living archive.

Next Steps

Friends of Pando plans to expand recordings and pair acoustic data with systematic experiments to map root connectivity, study water flow, investigate insect colonies and estimate root depth. The project began as a blend of art and exploration, but it is increasingly seen as a promising tool for non-invasive ecological research.

Note: While the recordings are compelling, definitive confirmation of vibration pathways will require controlled, repeatable experiments.