biocenosis

Biocenosis is the living component of a habitat, referring to the community of organisms that inhabit a given area and interact with each other and with the abiotic environment, forming a cohesive biological system. The term was introduced by Karl Möbius in the 19th century to emphasize interdependence among species within an environmental context. Biocenosis includes all flora, fauna, fungi, and microorganisms present in an ecosystem, organized into functional groups such as producers, consumers, and decomposers.

Its structure is shaped by species composition, population sizes, spatial distribution, and interaction networks like competition, predation, parasitism, mutualism, and symbiosis. Energy and matter flow through trophic levels, while cycles of nutrients link biocenosis to the surrounding abiotic biotope.

The concept is often discussed in relation to ecological succession, where a biocenosis develops and changes following disturbance, potentially moving through stages toward a climax community. Biocenosis is context-dependent and can vary with scale and habitat, from a pond or forest patch to a soil microbial community. Microbial communities are sometimes described as microbiocenoses, reflecting the same idea at the microscopic level.

In modern ecology, biocenosis is studied as part of ecosystem or community ecology, using measures of diversity, species interactions, and stability. The term remains a useful, if historical, descriptor of the interconnected living components that characterize a habitat.