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V. THE DYNAMICS
OF THE ANIMAL COMMUNITIES
§ DYNAMIC PLANT COVER - DYNAMIC ANIMAL ASSEMBLAGES
The profound differences between plant and animal communities can be
most clearly seen in phenomena triggered by dynamic changes in the
biocoenoses.
Changes in plant cover are of two types: the appearance of the plant cover
changes by season, relatively quickly and visibly (aspects), or undergoes a
slowly progressing, relatively gradual change, which can only be recognised
through long-term, continuous studies, and is independent of the seasons
(succession).
The aspects do not influence the composition of the association; they show
a characteristic sequence, visible by the changing seasons, and represented
by different species groups. The succession, on the other hand, influences
the composition of the association, causing the dropping out of certain species
and the appearance of new ones; so this is the process of the formation of a
new association.
It is obvious that the composition of animal associations must, in some
form, follow both kinds of changes, because both directly impact the
corrumpent elements. Apart from these, other changes, which have no parallel
in the plant kingdom, can also occur in the zoocoenosis. These are due to
the previously mentioned profound differences between plants and animals,
and is the precise cause of the kaleidoscope-like variability that we attempt
to conceptualise below.
§ THE ASPECTS
Changes in the seasons influence the animal communities, too, either by
influencing their ontogeny (in poikilotherms) or behaviour (migrating birds,
hibernation in mammals). Consequently, animal communities also have
aspects.
The aspect is a periodically returning, season-dependent change in the
same animal community, reflecting the concurrent seasonal changes in plant
cover. All animal communities appear as a series of aspects, following each
other in a regular manner and, generally, show the same species combinations