Dominant species

Definition

A species that exerts disproportionate control over community structure through high abundance, biomass, or ecological influence, thereby shaping the composition and dynamics of associated species in an ecosystem.

Etymology

From Latin dominari (to rule, govern) + species (kind, appearance).

Example

In eastern deciduous forests, the ant Formica exsectoides often acts as a dominant species in soil communities, regulating arthropod diversity through aggressive territory defense and aphid-tending activities that alter local food webs.

Synonyms

• ecological dominant

Related Terms

• Keystone species
• foundation species
• ecosystem engineer
• competitive exclusion
• Biomass
• community structure
• abundance

Usage Notes

Contrast with keystone species, which exert strong influence despite low biomass. Dominance is scale-dependent: a species may dominate locally (patch dominance) or across a landscape. In insect ecology, dominance is often measured by trap catches or colony counts rather than biomass. The term carries no implication of evolutionary fitness or long-term persistence.