In a groundbreaking study published in the peer-reviewed journal Cell on Thursday, scientists have uncovered a hidden world of communication within our green companions. Your houseplants may be speaking to you at a frequency too high for human ears to detect.
The research, led by Lilach Hadany, a senior evolutionary biologist and theoretician at Tel Aviv University, reveals that plants emit high-pitched clicks under stress due to drought, infections, or cuts. While these clicks are at the volume of a normal human conversation, they exist in the ultrasonic range, ranging from 40 to 80 kilohertz, well beyond the typical human hearing range of up to 16 kilohertz.
“It’s like a symphony of clicks that we’ve been oblivious to all along,” remarks Hadany
Stressed Plants Scream, Calm Plants Hum
The study, conducted in collaboration with researchers from MIT and Harvard, focused on tomato, tobacco, and cactus plants. When healthy, these plants produced minimal sounds, averaging less than one sound per hour. However, when subjected to stress, such as cutting or drought, the plants emitted a chorus of clicks, providing an auditory signal of their distress.
Listen to the sounds emitted by a tomato plant
The intriguing aspect is that these ultrasonic emissions may not be entirely random. Hadany suggests that creatures such as bats, moths, and mice be able to detect and interpret these sounds, potentially gaining insights into the condition of the plant and its species.
The research team utilized ultrasonic microphones to capture the elusive sounds. “You need specific equipment like ultrasonic microphones to record the sounds,” Hadany explained. The findings raise questions about the potential for long-range communication among plants and their ability to convey distress signals.
Nature’s Hidden Symphony: Animals Hear What We Can’t
While the study does not fully explain how plants generate these sounds, the researchers suspect a connection to cavitation. This phenomenon occurs when stressed plants release air bubbles in their circulation system, causing vibrations.
Machine learning algorithms were employed to analyze the recorded sounds, distinguishing stressed plants from healthy ones and even identifying different stress types and plant species.
This discovery opens up a realm of possibilities, from understanding plant-to-plant communication to potential applications in agriculture. The researchers speculate that tailoring water use based on the “noise” individual plants make could lead to more sustainable food production, addressing the rising global demand for food.
Amid this silent symphony, our leafy companions may be whispering secrets, contributing to a deeper understanding of the intricate language of nature.