Oldal 155 [155]
VIII. AGROBIOCOENOSES
AND THEIR ZOOCOENOSES
Can we speak of agrobiocoenoses at all, and can we call the cultivated areas
biotopes, and their animal associations biocoenoses?
Several authors reply with a definite “no’, which follows from making
“balance” the criterion of a biocoenosis, and separating humans from the
elements of the biocoenosis. We have already articulated our opinion about
the concept of balance, now we must examine the role of humans.
As a preamble, we declare that we consider biocoenosis as any animal
association that fulfils the criteria detailed in the chapter on biocoenosis, thus,
also associations of cultivated areas. The only concession is that the biocoenoses
influenced by humans will be called culture-biocoenoses (Balogh, 1953).
When culture-biocoenoses are defined as biocoenoses under continuous
human influence, it becomes obvious that there are various degrees of influence,
and the anthropogenic factors operating in culture-biocoenoses are active not
only in cultivated fields and orchards, but, also — even if in milder form -,
in meadows, forests, wetlands and watercourses, causing divergent changes
there. We cannot draw a sharp line; humans have an impact wherever they
settle. This is a most visible characteristic in forests, where all degrees occur
from a minimal maintenance of a natural forest, to establishing a new
plantation, including planting non-native species. As we leave a human
settlement, where forest disturbance is highest, the impact diminishes with
increasing distance. Can we draw a sharp line here and, if we cannot, are we
justified in making the definition of a biocoenosis as dependent on human
influence, or not?
The essence of the biocoenosis is not whether it is under human influence
or not, but that it is an association of living things. This association can live,
develop and undergo succession in the absence of human influence, and can
do so without, or because of, human impact. The only difference is that, in
the first case, we do not have to consider anthropogenic factors, while we
must in the latter instance.
Rammner (1953) has, most recently, considered the question ofa biocoenosis
on areas under agricultural cultivation, and he concluded that these cannot
be considered biocoenoses. We agree with the author that a biocoenosis is
not a random collection of various animals and plants, but an association in