Listen... Plants Too Speak

As early as in 1880, Charles Darwin demonstrated that plants could sense light, moisture, gravity, pressure and possessed several other qualities. Over the years, many scientists have proved that plants are sentient beings and move and respond to sensation. The subject is still controversial among the scientific community. Monica Gagliano is research associate professor of evolutionary ecology and former fellow of the Australian Research Council who has pioneered a brand-new research field of plant bioacoustics. In her latest book, Thus Spoke the Plant: A Remarkable Journey of Groundbreaking Scientific Discoveries and Personal Encounters with Plants, she, for the first time, has experimentally demonstrated that plants emit their own ªvoicesº and detect and respond to the sounds of their environments. In these excerpts, Gagliano writes about how the pea plant responds to acoustic vibrations to locate water

Oryngham means thank you for listening in the language of the plants. It is not a word, as we humans understand it, because its meaning cannot be spoken—nor can it be heard. However, we can experience it by feeling with our bodies and listening to what our ears cannot hear. When we learn to listen to plants without the need to hear them speak, a language that we have forgotten emerges; it is a language beyond words, one that does not wander or pretend or mislead. It is a language that conveys its rich and meaningful expression by bypassing the household of our mind and directly connecting one spirit to another. This language belongs to plants, and so do these stories.

IN GENERAL, organisms use various kinds of information transmitted by smells, sounds, lights, or magnetic fields in order to make good choices and avoid fatal errors. Based on this idea and as instructed by Ayahuma, I designed the experiments with the peas in the maze to test how roots choose the direction that correctly leads them to water, depending on the cues available. Particularly, could the roots of the young peas sense the acoustic vibrations generated by water moving underground or inside pipes? Could they use the sound of water alone to detect and find its source, when no actual water was available in close vicinity?

To answer this, I wrapped a sealed, soft plastic pipe through which water was constantly flowing around the base of one side of the maze, but the water itself was never directly accessible to the plants. Then I compared the choices roots made in these mazes to those they made growing in mazes where the soil was kept moist by actual water contained in the small plastic tray attached at the base of one side of the maze, hence producing a moisture gradient.