The Science Behind Plants Making Sounds When Stressed

There is some evidence to suggest that plants may make sounds when they are under stress. While plants don't have vocal cords, they do produce sounds in other ways. For example, some plants produce ultrasonic vibrations when their stems are bent or when they are exposed to certain kinds of stress, such as drought or insect infestations.

The sounds produced by poplar trees are not audible to the human ear, but they are within the range that other mammals, insects, and possibly plants can detect. Lilach Hadany, an evolutionary biologist at Tel Aviv University and co-author of the study, suggested that it is possible that other organisms have evolved to perceive and respond to these sounds. For instance, a moth that plans to lay eggs on a plant or an animal that intends to eat a plant could use the sounds to assist them in making their decision.

The idea that plants can make sounds when they are stressed is a relatively new area of study, and researchers are still working to understand the mechanisms behind this phenomenon.

In one study, researchers at Tel Aviv University in Israel found that tobacco plants produced a distinct clicking sound in response to caterpillar feeding. The researchers used a laser beam to measure the vibrations produced by the plant and found that the clicking sound was produced when the plant's stem and leaves moved in response to the caterpillar's chewing.

Another study published in the journal Trends in Plant Science found that some plants may also produce sounds in response to changes in the environment, such as changes in temperature or humidity. The researchers suggested that these sounds may be a way for plants to communicate with each other and respond to changes in their surroundings.

Here are some more detailed explanation

1. How plants produce sounds: Plants don't have vocal cords or the ability to produce sounds in the same way that animals do. However, they do produce vibrations in response to various stimuli. When a plant is under stress, such as from a pest attack or drought, it can produce ultrasonic vibrations that can be detected using specialized equipment. These vibrations are often too high-pitched for humans to hear, but they can be measured using tools like laser vibrometers.

2. What kind of stress triggers plant sounds: Research has shown that a variety of stresses can trigger plant sounds, including insect infestations, drought, exposure to certain chemicals, and even high levels of light. For example, one study found that maize plants produced ultrasonic vibrations in response to drought stress, while another study found that soybean plants produced sounds in response to herbivore damage. In some cases, the sounds may be a result of the physical stress on the plant's tissues, while in other cases, they may be a result of changes in the plant's metabolism or physiology.

3. How plant sounds are measured: Researchers use a variety of techniques to measure plant sounds, depending on the type of sound being studied. Laser vibrometry is a common technique for measuring ultrasonic vibrations, while microphones and other acoustic sensors can be used to pick up sounds in the audible range. These tools are often used in controlled laboratory settings, although researchers have also used them to study plants in the field.

4. What the sounds mean: While the exact meaning behind plant sounds is still being explored, there is some evidence to suggest that they may play a role in plant communication and defense. For example, some studies have suggested that plant sounds may serve as a warning to neighboring plants that a pest attack is underway. Other studies have suggested that the sounds may help plants coordinate their responses to environmental stresses, such as by triggering the production of defensive compounds. Still, other studies have suggested that the sounds may be a byproduct of the plant's metabolic processes and may not have a specific function.

Overall, the idea that plants can produce sounds when under stress is a fascinating area of research that is still in its early stages. While more work is needed to fully understand the mechanisms behind plant sounds and what they mean, the evidence so far suggests that plants may be much more complex and sophisticated than we previously thought.