Ecological community

Definition

An assemblage of populations of multiple species that co-occur in the same geographic area and interact through competition, predation, mutualism, or shared environmental responses. The term emphasizes species composition, relative abundance, and trophic structure rather than physical habitat alone. In entomology, communities are often studied at scales ranging from a single plant (e.g., phytophagous insects and their parasitoids on a cottonwood) to landscape mosaics (e.g., ground-dwelling beetle communities across forest–field edges).

Etymology

Greek oikos (household, place to live) + logos (study) + Latin communitas (commonness, shared duty)

Example

A riparian arthropod community along a desert stream might include predatory aquatic insects (dragonfly nymphs), riparian spiders (Tetragnatha spp.), emerging midges as prey, and terrestrial beetles that forage at the water's edge—species linked by energy flow and habitat boundaries rather than taxonomic relatedness.

Synonyms

• biotic community
• biocoenosis
• life assemblage

Related Terms

• Population
• Ecosystem
• guild
• Trophic level
• Species richness
• beta diversity
• habitat patch
• assembly rules

Usage Notes

Distinguish from ecosystem (includes abiotic components) and from population (single species). 'Community' is scale-dependent: a leaf-litter community to a soil ecologist may be a mere subplot to a landscape ecologist. The term carries no implication of mutual benefit; species may coexist without direct interaction. Some authors reserve 'assemblage' for spatial aggregations without proven interaction, using 'community' only where ecological linkages are demonstrated.