BIOCENOSIS

B. is a dialectically developing unity that changes as a result of the activity of its components, as a result of which there are regular changes and changes in B. (succession), which can lead to the restoration of sharply disturbed B. (e.g., forests after a fire, etc.). There are saturated and unsaturated B. In saturated B. all ecological niches (see ecological niche) are occupied and the introduction of a new species is impossible without the destruction or subsequent displacement of the K.L. component B. Unsaturated B. are characterized by the possibility of introducing new species into them without destroying other components. It is possible to distinguish between primary forests that have developed without human influence (virgin steppe, virgin forest), and secondary forests that have been modified by human activity (forests that have grown on the site of reduced, the population of reservoirs). A special category is represented by agrobiocenoses, where the complexes of the main components of B. are consciously regulated by man. There is a whole gamut of transitions between primary B. and agrobiocenoses. The study of B. is important for the rational development of lands and water spaces, because only a correct understanding of the regulatory processes in B. allows a person to withdraw part of the products of B. without its violation and destruction.

B. is characterized by a division into smaller subordinate units - merocenoses, i.e. naturally composing complexes that depend on B. as a whole (for example, a complex of inhabitants of rotting oak stumps in an oak grove). If energetic. the source of B. are not autotrophs, but animals (e.g., bats in B. caves), then such B. depend on the influx of energy from outside and are defective, representing in essence merocenoses. In B. it is possible to distinguish other subordinate groupings of organisms, e.g., sinusias. B. is also characterized by the division into vertical groupings of organisms (tiers of B.). In the annual cycle in B. the number, stages of development and activity of individual species are changing, regular seasonal aspects of B.

The interrelations of organisms in B. are diverse. Except trofich. connections that define the food chain (sometimes very peculiar - see Parasitism, Symbiosis), there are connections based on the fact that some organisms become a substrate for others (topical connections), create the necessary microclimate, etc. It is often possible to trace in B. groups of species associated with a certain species and entirely dependent on the latter (combination).

The term "B." was proposed by him. biologist K. Mobius (1877). B. is a complex of organisms of biogeocenosis, formed as a result of the struggle for existence, natural selection and other factors of evolution. Three groups of organisms are distinguished by their participation in the biogenic cycle of substances in B. 1) Producers (producers) are autotrophic organisms that create organic. substances from inorganic; the main producers in all plants are green plants (see Photosynthesis). The activity of producers determines the initial accumulation of organic. substances in B. (see Biomass, Biological productivity). 2) Consults (consumers)-heterotrophic organisms that feed on autotrophic ones. Consults of the 1st order are herbivorous animals, as well as parasitic. bacteria, fungi, and other chlorophyll-free plants that develop at the expense of living plants. Consults of the 2nd order are predators and parasites of herbivorous organisms. There are consults of the 3rd and 4th orders (superparasites, superparasites, etc.), but in total there are no more than 5 links in the supply chains. At each subsequent trofich. the level of the amount of biomass is sharply reduced. The activity of the consults promotes transformations and displacements organically. substances in B., their partial mineralization, as well as the dissipation of energy accumulated by producers. 3) Reductants (reductants) - animals that feed on decomposing remnants of organisms (saprophages), and especially non-parasitizing heterotrophic microorganisms - contribute to the mineralization of organic matter. substances, their transition to a state assimilated by producers.

BIOCENOSIS (from bio... and Greek. koinos -general), a collection of plants, animals, microorganisms inhabiting a land or body of water and characterized by certain relationships both among themselves and with abiotic environmental factors (see Biotope).