Trees Make Noises, and Some of Those Sounds Are Cries for Help

Knowing what kinds of noises trees in distress produce means researchers may be able to target those most in need of emergency waterings during droughts

It’s easy to dismiss trees as inanimate features of the landscape, but these living, breathing organisms aren’t as stoic as they appear. Trees, it turns out, make all kinds of noises as they grow and respond to their environment. Happy, regularly growing trees sound different from drought stressed trees. Now, a team of researchers from Grenoble University in France is trying to pick out these cries for help amidst all the normal tree white noise in order to provide better, more targeted aid to trees suffering from drought, according to National Geographic.

In the case of drought, trees undergoing stress form tiny bubbles inside their trunks, NatGeo explains, which causes a unique ultrasonic noise.

Imagine using a straw to slurp the last few drops from the bottom of your glass: You have to increase the pressure even more. In drought-stricken trees, this increased pressure can cause the water column to break, allowing dissolved air to form bubbles that block water flow.

These breaks are called cavitations, and they can eventually lead to a tree’s demise, so researchers and managers are interested in identifying warning signs that indicate that a tree needs emergency watering.

Eventually, the researchers think this finding may lead to handheld microphones that specialize in diagnosing tree distress signals. Other contraptions could be permanently strapped to a tree, providing constant updates on the trees health and perhaps even trigger automatic watering systems in times of drought, a bit like a sprinkler system in a building releases its water when licked by flames. 

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