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§ The structural elements of the animal assemblage | 43
as the animal association becomes more and more rich. They constitute
a layer that reduces the animal material flowing towards the reducents, thus
it remains bound at the animal level (Balogh, 1953; Woynarovich, 1954).
How the intercalary element fit is often ad hoc and opportunistic. From a
theoretical point, they are not needed for a continuous flow of energy (and
material), as the reducents can themselves assure this. Their role, nonetheless,
must be declared essential, because they contribute substantially to soil
formation (Giljarov, 1949; Franz, 1950; Juehnelt, 1950; Dudich, Balogh and
Loksa, 1952; Feher et al., 1954), and their absence leads to grave problems
for the soil-based communities (Schaerffenberg, 1953) that provide soil
quality feedbacks and can induce changes in plant cover.
The intercalary elements have the most important role in the soil and the
layer immediately above, which is composed of litter and other organic debris;
these two biotopes cannot be separated because, due to intercalary activity,
they are in a constant, vertical relationship (Jahn, 1951). In the layers above
ground, however, their presence is entirely occasional (see connexus, Balogh,
1953). Here, most of them are probably show strong dispersion over large
areas. Consequently, they cannot be considered peregrinants, as wherever
where there are living organisms, they can find a connection point.
The hospitant elements (“guests”) are populations that feed on plant
products, nectar, pollen or animal excreta (honeydew, sweat, etc.) without
causing any harm to the plant or animal in question, or exerting a positive
or negative influence on any member of the biocoenosis. Hospitant elements
include many insects that regularly visit flowers but do not take part in
pollination. Ants visiting aphids, for example, are not hospitants, because
they induce them to feed more intensively and, also, protect them to a certain
extent. In such a role, they are conventional corrumpent semaphoronts. This
group is identical with Tischler’s (1949) “hospites” group, with the restriction
that populations that move to a place only to hide or overwinter do not
belong in this category, because their role is only passive. These belong to
the next group.
The “pro tempore” (temporary) elements only share the space with one
or more zoocoenoses. They mix with other populations only because they
seek sites for pupation, egg laying, perhaps overwintering, or hiding.
Characteristic examples include the egg clusters of Hysteropterum grylloides
on trunks of fruit trees, the soil-pupating caterpillars of Operophtera brumata
or Erannis (Hibernia) defoliaria, or the individuals of Eurygaster maura that
hide and overwinter in the litter at forest edges.
These temporary elements are, therefore, populations that have extended
residence in a foreign environment, yet they do not have any positive
connection to the plant-based resources of the site, and the association has
no need for them; it will continue to exist without them. However, they can
be followed by parasitic or episitic elements that will interact with the members
of the association, and themselves can fall victim to obstant elements that