Biology researchers have released a new report that explains how stressed plants emit airborne sounds.
The high-pitched ultrasounds, which are too high for human ears to detect, “may serve as potential signals or cues to their environment,” the researchers write, meaning plants can communicate danger to each other.
“We found that plants emit sounds, and that both drought-stressed plants and cut plants emit significantly more sounds than plants of any of the control groups,” reads the report. “We demonstrated for the first time that stressed plants emit remotely detectable sounds, similarly to many animals, using ultrasound clicks not audible to human ears. We also found that the sounds contain information, and can reveal plant state. The results suggest a new modality of signaling for plants and imply that other organisms could have evolved to hear, classify and respond to these sounds. We suggest that more investigation in the plant bioacoustics field, and particularly in the ability of plants to emit and react to sounds under different conditions and environments, may reveal a new pathway of signaling, parallel to VOCs, between plants and their environment.”
Previous research has shown that organic compounds set off signals to other plants when a plant was being attacked (eaten by an animal). Researchers have been trying to figure out how the plants exchanged the messages between each other, but this new study has strong evidence that it’s the ultrasounds that allow other plants to “feel” or “hear” these signals.
A study released in 2014 also revealed plants can sense when they are being harmed (eaten) and they actually try to fight it off by releasing chemicals.
Read the latest research report here.