Chemical Signaling: Poems on the Breeze

In your garden, plants are talking through chemicals. Their messages are clear to receivers: "Watch out, caterpillars are hungry!" "Brothers and sisters, make poison!" Plants are fluent communicators and incredible chemists.

Biogenic Volatile Organic Compounds (VOCS)

Plants communicate by emitting complex bouquets of chemicals called VOCs. This sophisticated language includes over 30,000 compounds released into air and soil from flowers, foliage, bark, and roots.

Plant Vocabulary

Finnish ecologist Jarmo K. Holopainen likens each compound to a word in plants' vocabulary. Combined, they express complex messages: cries for help, warnings, invitations to pollinators and seed-dispersers, and even internal plant communications.

Internal Communication and eavesdropping

A plant's chemical response to predation may be intended for itself, especially in woody plants without vascular systems. Nearby plants may "eavesdrop" on these signals to gain advantages against predators and environmental stressors.

Emerging Field of Study

Plant-to-plant communication through VOCs is a relatively new field. Though first observed in labs in the 1980s, extensive field studies are recent. Detecting and differentiating these often diffuse chemicals remains challenging.

Context in Plant Signaling

Like human language, context matters in plant signaling. In sparse environments with few threats, signals are specific to kin groups. In populated areas, plants use more public chemical channels to warn entire communities.

Kin Recognition and Plant Personalities

Plants are more receptive to warnings from their own kin. Interestingly, plants' individual "personalities" affect how seriously their warnings are taken by others in their community.

Multi Lingual Plants

Plants can "speak" multiple languages. Some summon insect bodyguards when attacked. Australian orchids mimic wasp pheromones to attract pollinators. This shows remarkable semantic dexterity in the plant world.

Human Interaction with Plant Signals

Though we don't "speak" plant, their signals influence us. These chemicals create flower perfumes, herb pungency, and fruit flavors. Forest VOCs like limonene and pinene have health benefits for humans.

Future Applications

If we could understand plant language, we might reduce pesticide use by triggering crops' natural defenses.