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§ The formation of the presocium, the habitat association | 89
a broader category, with more extensive energy needs, occurs above them.
This is the presocium. A presocium cannot exist if there were no species
with more extensive stadia, which extend to all semaphoront groups. Their
associated obstant and intercalary elements, by necessity, also extend to
whole groups of oecuses or biotopes. Among the eucoen catenae and
catenaria, there are semaphoronts that do not belong to any of them, yet
neither are they peregrinant elements, because they have trophic connections
to the plant cover as well as with similarly dispersed other populations. The
presocium is the association composed of such populations. If they did not
exist, the catenaria would continue to exist without them, which clearly
indicates their status as independent categories. Yet such tichocoen or acoen
elements are present, with their associated obstant and intercalary elements;
they form a wider associational category above catenae and catenaria, the
presocium.
For the tichocoen and acoen obstant elements, most of the catenaria of
the biotope constitute energy sources and, without them, they could not
persist. Thus, they are linked to several catenae; their fate depends on them
but, at the same time, they also exert an influence on these catenae. Hence,
the formation of the presocium, an associational category above the
catenarium. Its foundation is formed by those sustinent, intercalary and
corrumpent elements (see Elton’s (1927) “key industries”) that are present
in the whole biotope, and are connected to obstant and intercalary populations
of similarly wide distribution.
§ THE LIMITS OF ANIMAL COMMUNITIES.
THE CONCEPT OF SUPERSOCION
The fact that the different semaphoront groups of the same species fit into
various animal associations, and the different populations have contact with
other different elements in these associations, creates exceedingly complex
interrelationships (see Elton, 1927), that can be represented by using
connection diagrams (Tischler, 1951); this makes conceptualising the limits
of animal communities very difficult.
This leads to consideration of the question posed earlier (see p. 31): how
can we draw the limits of animal associations?
Based on the discussion so far, one reply is evident: to delimit animal
associations in space, in a manner as resolved for plant associations, is
impossible. Neither the biotope levels, nor oecuses, nor the limits of the
biotope can be perceived as if they were also borders of animal associations.
We have seen that individual groups of semaphoronts can change bioroph,
oecus or biotope, according to their ecological needs (Nagy 1944; Bej-Bienko,
in Tschegolev, 1951; Tischler, 1950; Bej-Bienko and Mishtschenko, 1951).
This fact is not changed by the existence of populations that occur only in