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44 | II. Biocoenosis and zoocoenosis
are active there. Such temporary elements can only be distinguished following
a spatially explicit approach, where they constitute obvious examples of
movement between these temporary elements and zoocoenoses. They well
illustrate the main reason why a zoocoenosis is not a topographic unit, in
contrast to a plant association. Temporal elements are members of a
zoocoenosis and they signal its presence, nearby or more distant; their
characteristic is that they have emigrated from the space that contains their
primary energy source, and now reside in a foreign space. Such spatial change
is a regular phenomenon in several populations.
The role of the peregrinant (vagrant) elements requires little explanation.
A characteristic example is the presence of a pea curculionid on an apple
tree in June, or the wood borers (Ipidae) in an open herb association
(Thalenhorst, 1951). Such peregrinants (“tourists”) perhaps include a
significant portion of insects present in any association that are considered
tourist only due to our scant knowledge; not being aware of their links to a
member of the association, or to the resident zoocoenosis.
This classification does not completely overlap with Tischler’s (1947, 1950)
four classes, and is also different because the latter is based on a relationship
to habitats; it considers the spatially delimited zoocoenosis from the point
of view of species, therefore the zoon, the animal assemblage, is suitable for
analysis. His indigenae group includes our corrumpents, obstants, and
intercalary element; the hospites group was already mentioned, while the
groups vicini and alieni are, perhaps, similar to peregrinants, forming two
subgroups, considering whether they arrived from nearby or from afar.
Such a grouping is legitimate in the analysis of a given spatial unit or plant
association, but this is the field of ecofaunistics that had to be separated from
coenology sensu stricto, using concepts liberated from a spatial view. Therefore,
Tischler’s eucoen - tychcoen, acoen and xenocoen terms cannot be used in
coenology; they refer to sharing the same space rather than forming a trophic
association.
We do not see the need to keep this framework in coenology, as this will
not change the status of semaphoronts foreign to the association. The example
mentioned by Tischler (turnip sawfly at field edges) points to a sustinent
rather than peregrinant.
The seven groups are, clearly, not of equal importance when we consider
the foundation of a zoocoenosis. They cannot be, because these groups include
animals collected without considering their ecological connections, and we
have already declared that they can be considered to belong to the fauna of
the given area, but this does not necessarily overlap with a coenosis.