A homogeneous area of the Earth's surface with a particular composition of living organisms (biocoenosis) and non-living components of nature (surface layer of the atmosphere, solar energy, soil, climate, etc.), which interact through the exchange of substances, energy and information, forming a single natural complex.

Biogeocenosis (from Greek βίος - life γη - earth + κοινός - common) is a system comprising a community of living organisms and a closely related set of abiotic environmental factors within the same area, interconnected by a cycle of material and energy flow (natural ecosystem). It is a stable, self-regulating ecological system in which the organic components (animals, plants) are inextricably linked to the inorganic components (water, soil).

Properties

A natural, historically evolved systemcapable of self-regulation and maintaining its composition at a certain constant level characterized by a cyclic cycle of substances an open system for input and output of energy, the main source of which is the Sun.

Key indicators

Species composition is the number of species present in a biogeocoenosis.

Species diversity is the number of species present in a biogeocoenosis per unit area or volume.

In most cases species composition and species diversity are not quantitatively the same and species diversity depends directly on the study area.

Biomass is the number of organisms in a biogeocenosis, expressed in units of mass. Most commonly, biomass is divided into:

biomass of producers,

biomass of consumers,

biomass of decomposers,

Productivity Sustainability,

Self-regulating capacity.

Spatial characteristics 

The transition from one biogeocenosis to another in space or time is accompanied by a change in the states and properties of all its components and, consequently, a change in the nature of biogeocenotic metabolism. 

The boundaries of a biogeocenosis can be traced by many of its components, but more often they coincide with the boundaries of plant communities (phytocenoses). 

The thickness of a biogeocenosis is not homogeneous, neither in the composition and condition of its components, nor in the conditions and results of its biogeocenotic activity. 

It is divided into above-ground, underground and underwater parts, which in turn are divided into elementary vertical structures - biogeo-horizons, which are very specific in composition, structure and state of living and dwelling components. 

The concept of biogeocenotic parcels was introduced to denote the horizontal heterogeneity or mosaicism of biogeocenosis. Like the biogeocenosis as a whole, this concept is complex because the parcels include vegetation, animals, microorganisms, soil and atmosphere as participants in the exchange of matter and energy.