Abiotic factors

Definition

Non-living chemical and physical components of an environment that influence living organisms, population dynamics, community structure, and ecosystem processes. In arthropod ecology, these include temperature, humidity, substrate type, wind, pH, salinity, and radiation—variables that directly affect insect development rates, spider habitat selection, and the geographic distribution of species.

Etymology

Example

Soil moisture and temperature—key abiotic factors—determine the vertical distribution of ground-dwelling beetle larvae; drought conditions can trigger estivation or force downward migration to cooler, more humid soil horizons.

Synonyms

• abiotic components
• abiotic variables

Related Terms

• biotic factors
• microclimate
• Habitat
• Ecosystem
• Niche
• environmental gradient
• edaphic factors

Usage Notes

Contrasts explicitly with biotic factors (living components such as competitors, predators, pathogens). Often subdivided into climatic, edaphic (soil-related), and topographic categories. Specialists distinguish between resources (e.g., water, minerals) and conditions (e.g., temperature, pH)—the former can be depleted, the latter cannot. In entomological field studies, abiotic factors are frequently manipulated or measured as covariates when assessing arthropod abundance or behavior.