Trees Cry For Help When They’re Thirsty

If a tree gets parched in a forest and no one is around to hear it, does it make a sound?

Apparently, yes. French scientists say they have discovered that trees make sounds when they are thirsty or starved for water. The physicists created a sensitive microphone that they attached to trees and found that the thirstier trees become, the louder the sounds.

In order to hear those sounds with your ear, researchers have to slow them down by a thousand times. What you hear are gurgling sounds, similar to a straw sucking up that last bit of milkshake. Trees drink by absorbing water through special tubes in their trunks called xylem. When groundwater dries up, the trees have to pull harder on whatever water is left – which can create air bubbles.

“Every time there was a sound, there were bubbles happening inside the tree. When these bubbles appear, it’s bad,” said Dr. Alexandre Ponomarenko. In the future, they believe forest officials could use handheld acoustic monitors to find stressed trees that need emergency watering to prevent permanent damage. He says there could even be a device that would attach to a tree and constantly listen for sounds and if needed, the device could trigger an emergency-watering system.

All of this is very important if drought becomes more common around the world because of climate change.