The Washington Post reports:

It sounds like fiction from “The Lord of the Rings.” An enemy begins attacking a tree. The tree fends it off and sends out a warning message. Nearby trees set up their own defenses. The forest is saved.

But you don’t need a magical Ent from J.R.R. Tolkien’s world to conjure this scene. Real trees on our Earth can communicate and warn each other of danger — and a new study explains how.

Injured plants emit certain chemical compounds, which can infiltrate a healthy plant’s inner tissues and activate defenses from within its cells, the new research found. A better understanding of this mechanism could allow scientists and farmers to help fortify plants against insect attacks or drought long before they happen.

For the first time, researchers have been able to “visualize plant-to-plant communication,” said Masatsugu Toyota, senior author of the study, which was published Tuesday in Nature Communications. “We can probably hijack this system to inform the entire plant to activate different stress responses against a future threat or environmental threats, such as drought.”

The idea of “talking” trees started to take root in the 1980s. Two ecologists placed hundreds of caterpillars and webworms on the branches of willow and alder trees to observe how the trees would respond. They found the attacked trees began producing chemicals that made their leaves unappetizing and indigestible to deter insects.

But even more curious, the scientists discovered healthy trees of the same species, located 30 or 40 meters away and with no root connections to the damaged trees, also put up the same chemical defenses to prepare against an insect invasion. Another pair of scientists around that time found similar results when studying damaged sugar maple and poplar trees. [Continue reading…]