Oldal 22 [22]
20 | I. The aim and position of zoocoenology in the system of biological sciences
forms a real community, and another group whose members are merely co¬
occurring due to their similar autecological needs.
The biocoenosis, though, is not merely an assemblage of individuals that,
due to their similar living conditions, occur together, but a higher unit, in
which the organisms are bound together (Thienemann, 1939). Therefore, we
have to separate the research approach that fulfils its objectives by identifying
and counting animals found in a certain plant association, from the other
branch of science that, by studying correlations, uncovers the inner
relationships (Keve-Kleiner, 1943).
The plant cover + its animal “filling” is called a biome (Clements, 1916:
“plant matrix with the total number of included animals”). This is not a higher
unit of a community, but - similarly to Schimper’s formation - a biogeographical
term (Tischler, 1950). Biome and biocoenosis are therefore basic units of two
totally different biological disciplines. The biome (for example, a desert,
tundra, prairie, alpine meadow, subalpine pines forest, etc.) can be a starting
unit of biogeographical studies, but this is not a higher unit above biocoenosis,
even though it contains several biocoenoses and, similarly, its animal filling
is not a zoocoenosis, even though it is composed of several zoocoenoses. The
term biome includes plants and animals; its plant component is a climatically
determined formation, and its animal component is the animal assemblage,
termed zoon by Tischler.
The zoon is thus the animal assemblage present in a certain plant association.
In reality, Tischler uses this name for the fauna of a higher unit of biotope,
called a bioregion, while the animal component of a biotope is called a
zoocoenosis. We cannot adhere to this, because the concept "zoon" does not
depend at all on whether, by this, we mean the animal assemblages of a
smaller or bigger area. The animals filling an association is a zoon, just as it
is of a larger category. The animal assemblage of the two areas, even if of
different species composition, is essentially not different because, by definition,
they are the same: an unsorted assemblage of animals in a given space. The
animal assemblage of a biotope is not the zoocoenosis, but a zoon, as several
zoocoenoses can live within one biotope (see Tansley, 1935: “Animal ecologists
[... ] constantly find it necessary to speak of different animal communities
living in or ona given plant community”; Glen, 1954: “a complex of smaller,
interlocking, dynamic systems”). Consequently, the animal inhabitants of a
plant association can, collectively, only be called a zoon, and this concept
cannot be used for anything else. If we consider the biome as a biogeographical
concept, its animal components cannot be anything else but a concept of
zoogeography. Indeed, this is what a zoon is and, thus, it cannot be considered
a sum of zoocoenoses, as the biome is not a sum of biocoenoses. The biome
(plant + animal), zoon (only animals), and climatic formation (only plants)
are biogeographical units, while the biocoenosis, phytocoenosis, and
zoocoenosis are concepts of communities, and they do not mix.