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§ The structural elements of a zoocoenosis | 49
to animal size. It is sufficient to point to what wild boar or deer can do in an
arvideserta; the corrumpent role of domesticated animals can be noticed
immediately on any grazed area. A flock of sheep does not sustain certain
characteristic desert formations, but can prevent the formation of a biocoenosis
characteristic of that biotope. Carnivorous mammals, on the other hand, are
obstant elements. The role of birds is very interesting: their obstant activity
is the reason for the development of bird protection for economic reasons,
albeit their populations often belong to more coeti; being not only corrumpents
but, importantly, sustinents in the life of a forest, as convincingly illustrated
by Turcek’s (1951) fascinating observations. Finally, not to ignore humans,
let us conclude that we belong to populations that are fully active in all
directions: corrumpent when building a city, obstant when protecting plants
and nature, intercalary in hygiene, sustinent with crop cultivation, hospitants,
or protempore, in the depth of primeval forests, and peregrinant all over the
uninhabited areas of the Earth.
§ THE QUESTION OF BALANCE IN THE BIOCOENOSIS
There is no doubt that multi-faceted human activities, wherever they meet
nature, will profoundly influence the life and composition of biocoenoses.
The longer this connection lasts, the more decisive human influence will be,
and several authors (e.g. Tansley, 1935; Bejbienko and Mistchenko, 1951;
Scsegolev, 1951) distinguish anthropogenic factors from abiotic and biotic
ones. In this respect, let us only state that anthropogenic influence, from
transient disturbance to sustained and long-lasting impact, is manifest to all
degrees.
This fact, when we link it to the concept of biocoenosis, takes on theoretical
importance, because since Resvoy (1924), most authors designate balance as
one of the criteria of a biocoenosis, and only associations able to self-regulate
- and thus be “in equilibrium” - qualify as biocoenoses. The first appearance
of this consideration, in almost identical phrasing, occurs in Bronn’s (1843,
cit. Schwenke, 1953) long-forgotten discourses. Following this principle will
logically lead to a conclusion that, in associations with sustained human
influence, self-regulation will cease to operate, the equilibrium is lost, and
what remains in the area in question can no longer be a biocoenosis, but an
inferior replacement. This is where Schwenke (1953) concurred, excluding
the areas under human agriculture from a biocoenosis, and calling it a
merocoenosis. Rammer’s (1953) standpoint is even more extreme.
We cannot agree with this position, because it does not separate the
concepts of biotope and biocoenosis, and because it forces such an undefinable
criterion as the equilibrium into the concept of biocoenosis and, excluding
the developmental potential of an association, it forces - without proof ¬
some kind of stability onto a biocoenosis.