Trees warn neighboring trees of insect attack through airborne chemical signals

Evidence

There is now compelling evidence that our elders were right—the trees are talking to one another. They communicate via pheromones, hormonelike compounds that are wafted on the breeze, laden with meaning. Scientists have identified specific compounds that one tree will release when it is under the stress of insect attack—gypsy moths gorging on its leaves or bark beetles under its skin. The tree sends out a distress call: “Hey, you guys over there? I’m under attack here. You might want to raise the drawbridge and arm yourselves for what is coming your way.” The downwind trees catch the drift, sensing those few molecules of alarm, the whiff of danger. This gives them time to manufacture defensive chemicals. Forewarned is forearmed. The trees warn each other and the invaders are repelled. The individual benefits, and so does the entire grove. — Robin Wall Kimmerer, Braiding Sweetgrass, 77

Categorization

• XREF: Vindicates the elders’ claim from paragraph 76 and connects to the Soundscape course’s listening to more-than-human voices. — connects to: Bark beetles combine long-range chemical with short-range acoustic signaling — Almo Farina, Soundscape Ecology: Principles,…, 788; Plants exchange warnings through distributed chemical signals without any central brain — Jamal Awil, The Whispering Archive: The Complete…, 162; Monoculture management and fire exclusion promote insect-induced vegetation mortality — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 1582

Broader Connections

• Plants exchange warnings through distributed chemical signals without any central brain #expands (0.90) — Jamal Awil, The Whispering Archive, 162
• Monoculture management and fire exclusion promote insect-induced vegetation mortality #corroborates (0.75) — S. T. A. Pickett and P. S. White, eds., The Ecology of Natural Disturbance and…, 1582