OCR Output

§ The system of biological sciences [ 23

Production biology aims to examine the flows of material and energy
through assemblages and communities of living beings, and to establish
qualitative and quantitative changes. Its main unit is the sum of the constant
and/or dominant populations, either by density or by biomass.

One remaining question is: what, then, is agrozoocoenology? Agro¬
zoocoenology is the sub-division of zoocoenology that considers the totality
of animal assemblages that live on cultivated areas, and its link to areas less
disturbed by humans, although they are connected to it by mutual influences.
Plant protection entomology is, in essence, agrozoocoenology (“biozoenotische
Entomologia’, Schwenke, 1953). We cannot consider it as a separate branch
of science, as its methods are identical to those of other zoological sciences
and, even if its subject matter is connected to agriculture, this does not make
it a separate science, only a link in the chain of universal science that connects
practice and science.

In the recent past, Peus (1954) dealt with, in his deeply thoughtful article,
the problems of biocoenology, and concluded that autecology, with its ecological
methods, can approach all the important problems, because all key questions
in an assemblage are problems of autecology. According to him, biotope and
biocoenosis, with all their features, are products of human imagination,
meaning fictions (“Gebilde des menschlichen Verstellungsvermögens”) and,
consequently, there is no such science as biocoenology (“die Biozoenologie
als Wissenschaft hat keinen real Grund’, p. 200).

In response to this surprising conclusion, we can only state that the otherwise
excellent author went too far following his interesting emphasis on autecological
studies. In all assemblages, there are reciprocities that exist only because, eo
ipso, of the existence of this assemblage. In all assemblages of living things,
there exist these exchanges that can only be perceived because the assemblage
in question exits there and then and, without these features, could not exist.
If we consider an assemblage as a coexisting unit, it presents special problems
that only exist because of the existence of this unit, and this - in our opinion
— goes beyond the framework of autecology. We imagine a completely different
mental picture when we pronounce “Festuca sulcata” than when using
“Festucetum sulcatae”. In the first case, we picture a single plant, and think
of its specific needs, while in the latter case, we picture a plant association,
with all the complicated interdependencies that are formed precisely due to
the association. The difference between the two is like the difference between
autecology and synecology, or biocoenology. Such a science can, therefore,
certainly be cultivated, and we can modify Peus’ arguments so that autecology
is indispensable for a successful pursuit of this branch of science.

The standpoint taken by Poljakov and Sumakov (1940, 1954) is similar in
many respects but not so drastic; they also negate the right to existence of
biocoenology, although they accept the concept of the biocoenosis as a unit
of coexistence. As it transpires from their publications, these authors object