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§ The concept of biocoenosis | 31 only practical reasons force us to do the opposite. We start with the associations of higher organisms that are visually perceptible, and continue to move in directions that, along tangible associative links, lead us into the invisible world of microbial organisms. These organisms are no longer members of an animal or plant association, but members of the biocoenosis itself. For us, the phyto- or zoocoenosis ends where we start including the microorganisms in the associations of higher plants or animals, as partners of life importance, incorporated within the true biocoenosis, and biocoenology is only correctly cultivated if we include all the interactions that exist among animals, plants and microbes. Consequently, the biocoenosis includes those living things that are not considered by either phyto- or by zoocoenology (Dudich, 1953) and are present, even if invisible (except as occasional macroscopic phenomena e.g. as the spots caused by microbial infections, rots, calcareous patches, soil formation), and yet can decisively influence the composition of the plant and animal association itself. Considering the relationship between soil organisms and soil nutritional resources, remarkable studies have attempted to classify the soils themselves by qualitatively and quantitatively analysing the former (Franz, 1950, 1951). Nevertheless, phyto- and zoocoenology study the composition, the structure of phyto- and zoocoenoses, and their impact on each other, as if cutting the links that bind them to the totality of the biocoenosis. This, however, cannot be faulted on a theoretical basis, because it is unavoidable due to methodological constraints (Tansley, 1935, Pavlovsky and Novikov, 1950). The composition of plant and animal associations can also be studied without considering their links to the microbiome; in fact, the role of the latter can be surmised from the structure of the former. The question of “why” will inevitably force the researcher to look beyond the basic composition of the plant or animal associations and investigate the wider horizons of the biocoenosis; thus, the research area of the “full” biocoenology will, besides the phyto- and zoocoenology, always include microbiology as well. The chapter on the concept of biocoenosis cannot be concluded without trying to clarify its relationship towards similar, or similar-sounding ones appearing in the literature. The biome (Clements, 1916) was already mentioned; others encountered include the ecosystem (Tansley, 1935) and the biogeocoenosis (Sukhatchev, 1947, 1949, 1950). These three concepts only partially overlap but are not identical, and are also different from the biocoenosis. Firstly,we need to state that the biome and biogeocoenosis are biogeographical, while ecosystem and biocoenosis are biocoenological concepts; the four concepts can be separated when presented together. The biome denotes the full spectrum of living beings in a region, that is in a large, physiognomically identifiable spatial unit. The concept of a biome therefore includes only living beings, and the abiotic factors influencing them are only present in their effects and the consequences of these effects. The
