Biocoenosis

In the palaeontological literature, the term distinguishes "life assemblages", which reflect the original living community, living together at one place and time. In other words, it is an assemblage of fossils or a community of specific time, which is different from "death assemblages" (thanatocoenoses). No palaeontological assemblage will ever completely represent the original biological community (i.e. the biocoenosis, in the sense used by an ecologist); the term thus has somewhat different meanings in a palaeontological and an ecological context.

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

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

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

Ecosystems

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.