Oldal 33 [33]
§ 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