The word "biotic" (from Greek - biotikos) is translated as life. It is this meaning that the concept of “biotic factor” has. In the most generalized form, this scientific category denotes a set of conditions and parameters of a living environment that directly affect the vital activity of organisms. The famous Soviet scientist and zoologist V.N. Beklemishev classified all biotic environmental factors into four main groups:
- topical factors - those associated with a change in the environment itself;
- trophic - these are factors characterizing the nutritional conditions of organisms;
- Fabric - factors characterizing the Fabric relationships in which organisms of one species use organisms of another species (or parts or vital products) as a building material;
- foric - associated with the movement of organisms of one species by organisms of another species.
As a rule, the action of the factors under consideration is manifested in the form of interactions between organisms located in a given environment and the effect that they exert on each other. An important manifestation of the action of biotic factors is the way in which all organisms act on the environment. Such an effect is more narrowly described by biotic environmental factors.
In the whole set of interactions between organisms saturating the environment, relationships are formed, which are usually divided into direct and indirect. In addition, distinguish between intraspecific and interspecific relations. In the first case, interactions and their consequences are considered among representatives of one biological species, which are characterized by intraspecific competition and the phenomena of group and mass effects. Interspecific relationships are usually very diverse and reflect an extremely wide range of interactions. These relationships, due to their diversity, are classified into the following types:
- neutralism is a type of relationship in which the biotic factor determines the completely neutral (neither beneficial nor harmful) interactions between organisms;
- sinoykia - this type of relationship in which a representative of one species uses the body of another to equip his home without causing any harm. This type is also called lodging or cohabitation;
- competition is a purely antagonistic relationship that occurs between organisms located in a particular environment and interacting with each other and with this environment. There is a direct struggle for a “place in the sun”, for food, shelter and other resources;
- mutualism - a type of interspecific relationships in which the biotic factor determines exclusively “mutually beneficial” coexistence of organisms;
- protocooperation is a type of relationship in which organisms, at least for a while, can do without each other without much damage to their existence;
- under commensalism, the biotic factor provides an interaction between organisms in which one of them uses the other as a home without causing significant harm. Such an example can be bacteria that are present in large numbers in the human gastrointestinal tract;
- amenalism is a type of interspecific relationships characterized by such an interaction in which the harm caused by one organism to another is indifferent to it;
- a variety of relationships in which organisms living at the expense of other organisms do harm to the latter, called parasitism;
- predation.
As a rule, all types of antagonistic relations ensure the preservation of populations of species and the maintenance of their number.