Any site of the environment suitable for life is inhabited by animals, microorganisms and plants. All this community is called a biocenosis. It exists by the rules and submits to the laws.
The biocenosis (from the Greek words bios - life and koinos - the general) is a set of microorganisms, plants, animals and mushrooms inhabiting a certain area of land or a reservoir. The site is called as a biotope. A biotope together with a biocenosis represent a biogeocenosis. For the first time such name was offered by the German biologist K. Möbius in 1877. Any biocenosis is inhabited by the organisms capable to produce organic matter from inorganic by means of solar energy or chemical reactions. Such organisms carry the name of producers. One more type of the population of a biocenosis - konsumer or consumers. They eat other organisms. The animals eating the decaying remains of organisms, the called redutsentam (reducers) and not parasitizing heterotrophic microorganisms. Redutsenta mineralize organic matter, after this substance become suitable for assimilation by producers.
Organisms in a biocenosis consist in diverse relationship. Except the trophic communications defining food there are communications based that some microorganisms become substrate for others, provide a microclimate, etc.
As all members of a biocenosis are subject to changes in development, the biocenosis also changes. These changes are quite natural. Sometimes they lead to restoration of the broken biocenoses. Sometimes, that there is a settling of already created biocenoses new organisms. When the community has nonsaturated character, such invasion does not bear for itself any changes. If a biocenosis saturated, then settling of new types is possible only as a result of destruction of earlier introduced. There are primary biocenoses in which creation only natural factors took part. Secondary, as a rule, are created by means of intervention of the person. The special group is made by agrobiocenoses where relationship of parts is completely regulated by the person. Between all these versions there is a set of transitional forms.