Biocoenosis

A freshwater aquatic and terrestrial food web.

A biocenosis (biocenose, biocoenose, biotic community, biological community, ecological community), coined by Karl Möbius in 1877, describes the interacting organisms living together in a habitat (biotope). This term is rarely used in English, as this concept has not been popularized in anglophone countries. Instead, English-speaking scientists normally use the terms ecosystems or communities.

Based on the concept of biocenosis, ecological communities can take in various forms

• Zoocenosis for the faunal community,
• Phytocenosis for the flora community,
• Microbiocenosis for the microbial community.

The geographical extent of a biocenose is limited by the requirement of a more or less uniform species composition.

Ecosystems

Main article: Ecosystem

An ecosystem,originally defined by Tansley (1935), is a biotic community (or biocenosis) along with its physical environment (or biotope). In ecological studies, biocenosis is the emphasis on relationships between species in an area. These relationships are an additional consideration to the interaction of each species with the physical environment.

Biotic communities

The side of a tide pool showing sea stars (Dermasterias), sea anemones (Anthopleura) and sea sponges in Santa Cruz, California.

Biotic communities vary in size, and larger ones may contain smaller ones. Species interactions are evident in food or feeding relationships. A method of delineating biotic communities is to map the food network to identify which species feed upon which others and then determine the system boundary as the one that can be drawn through the fewest consumption links relative to the number of species within the boundary.

Mapping biotic communities is important identifying sites needing environmental protection, such as the British Site of Special Scientific Interest (SSSIs). The Australian Department of the Environment and Heritage maintains a register of Threatened Species and Threatened Ecological Communities under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

See also

• Community (ecology)
• Hylozoism
• Population biology

Further reading

• Kendeigh, S. Charles. 1961. Animal Ecology. Prentice-Hall, Inc., Englewood Cliffs, N.J., 468 p.
• Möbius, Karl. 1877. Die Auster und die Austernwirtschaft. (tr. The Oyster and Oyster Farming) Berlin. (English translation) U.S. Commission Fish and Fisheries Report, 1880: 683-751.
• Tansley, A. G. 1935. The use and abuse of vegetational concepts and terms. Ecology, 16(3): 284-307.