Ramsey Lab

Scientists have confirmed something almost unbelievable… forests aren’t silent at all. Researchers from the University of Florence discovered that trees communicate using ultrasonic sound pulses — frequencies so high (20–200 kHz) that humans can’t hear them. In the forests of Casentino Forest, European beech trees under drought stress began emitting rapid ultrasonic “clicks.” These weren’t random noises — they were warnings. And here’s the wild part… Nearby trees heard the signal and reacted within hours. Before experiencing any drought themselves, they started closing their stomata (tiny pores on leaves) to conserve water proving they received and acted on the warning. Scientists traced the sound to tiny internal events called cavitation microscopic bubbles forming and collapsing inside the tree’s water transport system. These clicks travel through air and soil, reaching trees up to 50 meters away.