Like a person gasping for air when it’s in short supply, living trees make sounds when they are running out of water… A team of French scientists is trying to pinpoint the strange noises.
Lab experiments at Grenoble University in France have isolated ultrasonic pops, which are 100 times faster than what a human can hear, in slivers of dead pine wood bathed in a hydrogel to simulate the conditions of a living tree. So yes, trees make noise when they are thirsty, when they are under drought stress:
So what is going on in those trees?
Trees drink by absorbing ground water through vein-like structures called xylem. When the supply is short they have to work harder to pull up water. This stress can cause the water stream to rupture and produce air bubbles. Too many air bubbles can lead to the death of the tree. The scientists have discovered that about half of the sounds made by trees are due to their drinking process.