Chemical Ecology

Chemical ecology is the study of how organisms use chemical signals to mediate interactions within and between species, and how the chemical landscape of an environment shapes community structure, defense strategies, and resource competition. Chemical signals — pheromones, allelochemicals, kairomones, allomones — are information molecules that propagate through air, water, and soil, creating invisible communication networks that can span vast distances or operate at microscopic scales. The field reveals that ecosystems are saturated with chemical information: plants emit volatile organic compounds when attacked by herbivores, recruiting predators; microbes release quorum-sensing molecules that coordinate collective behavior; and fungi alter soil chemistry to suppress competitors. Chemical ecology is the silent dimension of sensory ecology, operating below the thresholds of human perception but structuring the information architecture of ecosystems as fundamentally as sound or light. See Infochemical.