Researchers affiliated with the Friends of Pando environmental project captured the unique soundscape of the Pando poplar grove in Utah, USA. The findings, documented for a scientific audience, appear in Acoustic, a respected journal in the field of environmental acoustics and biology.
The Pando Forest spans more than forty hectares and comprises about 47,000 individual trunks belonging to the Populus tremuloides species, commonly known as quaking aspen. Despite appearing as a single “tree,” these trunks are interconnected by a common root system and share nearly identical DNA. This remarkable unity has earned Pando recognition as one of the largest and oldest living organisms on the planet, with an estimated weight around 6,000 tons and an age that researchers dating place at roughly 12,000 years.
In a novel methodological twist, scientists placed hydrophones—sensors designed to pick up acoustic signals in aquatic or damp environments—around the grove’s network of roots. Their goal was to listen for low-frequency vibrations that manifest as rumbling sounds within the soil and water channels. The recordings grew more intense during storm events, suggesting a direct link between meteorological forces and the tree’s subterranean hydraulic processes.
Observations from the hydrophones revealed that branches occasionally collided, sending detectable signals up to 100 feet from the recording sites. These interactions provide a window into how the grove remains structurally connected across vast distances, with mechanical stresses propagating through the root system and across the interconnected trunks.
Explaining the potential implications, Lance Auditt, founder of the Friends of Pando, noted that this project began as an artful exploration but holds substantial scientific value. Wind energy transformed into vibrational signals traveling through the root network offers a noninvasive method to probe the inner hydraulics of Pando on a scale that traditional observational techniques cannot easily achieve. Such an approach could illuminate how water moves through the grove, revealing hidden dynamics without harming the trees themselves.
The ongoing research aims to expand the dataset to map how water moves through the root-woven architecture and to understand how the strings of branches are physically and acoustically connected. In addition, the team hopes to glean information about subterranean insect communities that contribute to the root system’s ecology, potentially enriching knowledge about the grove’s resilience and longevity. This multidisciplinary effort sits at the intersection of ecology, physics, and data science, illustrating how sound and vibration analyses can complement conventional field studies.
As researchers build a more complete acoustic profile of Pando, the work may yield broader insights into the behavior of large clonal organisms and their interaction with environmental forces. The study invites further inquiry into how similar root networks in other forests respond to seasonal changes, drought, and storm events, opening doors to comparative analyses across ecosystems. In the end, the project not only documents a remarkable natural wonder but also demonstrates how innovative, noninvasive monitoring techniques can deepen our understanding of forest hydraulics, microbial life in soils, and the quiet yet telling conversations that occur beneath a forest floor.
The final wave of questions touches on insect populations and their roles in root-system ecology. Researchers are eager to explore which insect communities thrive beneath Pando during autumn and how their activities influence root health and nutrient cycles. The pursuit of these answers highlights the grove’s status as a living laboratory, inviting ongoing observation and thoughtful interpretation by scientists and environmental stewards alike.