Oldal 60 [60]
58 | IL. Biocoenosis and zoocoenosis
are, apparently, well-adapted. This effect can have an impact on homeothermic
as well as poikilothermic animals, sufficient to remember the effects of hard
winters on birds.
How can we talk about equilibrium when a weather anomaly, in whatever
direction, threatens the life of living things? Should we also classify this
impact as disequilibrium? Why would we decide about the coenosis status
of an association on this basis, when its essence is clearly not this unusual
influence, but the interactions that bind it together? Even though a coenosis
can be disturbed by irresistible forces, extreme temperature, storms, flood,
fire and humans, it can be restored after every such disturbance. Restored,
because the interactions are so much the essence of a biocoenosis that it has
to appear wherever living beings are associated, as life itself is present.
In this respect, we have to seek the correct explanation of self-regulation,
too. What constitutes the ability to self-regulate? We agree with all authors
who claim that this is the process that recreates the disturbed order. We see
the same in agrobiocoenoses, where this tendency is the only explanation
for the phenomenon that agriculture must compete continuously with the
pioneer weeds that try to occupy space; that specially adapted corrumpents
break into monocultures, and devour everything that is foreign to the biotope,
and; in areas where cultivation has stopped, succession continues after a few
years. This ability to self-regulate is not changed by constant human
interference. Therefore, we have to distinguish these from coenoses in which
human influence is negligible, and this is why we call them agrobiocoenoses.
No one can doubt that agrobiocoenoses are different from “natural” ones,
but this difference is sufficiently indicated by a different name, although the
forces regulating the community are identical in both.
The interactions can be disturbed by several factors, and our current
knowledge indicates that such smaller or bigger disturbances are common
in any biocoenosis, despite us noticing only the more obvious ones.
The interaction is undisturbed if; the producent level does not suffer from a
catastrophic factor, other structural elements do not exhaust their energy bases,
and due to their activities, the conditions in the biocoenosis become richer, and
allow the insertion of new elements.
Disturbance in the interaction occurs when the producent level suffers a
catastrophic factor, or other structural elements use their energy base to such
an extent that conditions for life are restricted, and new elements can only insert
themselves with difficulty, or not at all.
The survival of a biocoenosis is only threatened by interaction disturbances
that endanger the existence of the most important producent elements. In
the interactions of a biocoenosis, or its smaller constituent communities,
such disturbance can only be caused by sudden catastrophic factors
(“catastrophic mortality factor”, Ullyett, 1947). Its cause can be extraordinary
temperature, flood, fire, etc.; in zoocoenoses, it can also be the activity of
obstant elements. The result is a new beginning; a new biocoenosis develops,