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§ Ouantitative characteristics | 131
be attributed to this space. As we have seen, from the point of view of
a zoocoenosis, the biotope means both a space suitable for its activity, and
the plants growing in that space; therefore, for the animals, the plants also
constitute space. Space interpreted in this way allows that we measure the
abundance by area or volume of space, but only for elements that are directly
linked to plant-based energy sources.
This view places the evaluation of abundance into a totally different light,
liberating it from all artificiality. Studying the abundance of sustinent elements
using, for example, a quadrat, strip or other artificially separated spatial
method, will say nothing if we forget that, for the zoocoenosis, plants are not
only “space” but also a source of energy. The abundance of Adrena hattorfiana,
that visits only Knautia, Cichorium or Scabiosa, or that of Melitta nigricans,
visiting exclusively Lythrum salicaria (Olberg, 1951), can reach a certain
(positive) value only where these plants are present. Likewise, the abundance
of Aporia crataegi cannot be measured in regularly placed quadrats, only on
trees where it can survive. Certain oeci can attract disproportionate numbers
of flower-visiting Apoidea: Möczär (1954) found that in a Festucion sulcatae
stand, 31.3% of apoid species, and 45.9% of their adult semaphoronts, visited
one plant species, Eryngium campestre. The quality of litter will probably
exert a significant influence on the abundance of litter-consuming intercalary
elements. It may be that our knowledge in this area is not vast but, again, this
indicates that zoocoenological studies are not possible without deep
idiobiological knowledge.
The abundance of corrumpent, sustinent and intercalary syrmatophagous
elements is studied through projection onto the plant cover, and the abundance
of other elements will be related to this factor. Naturally, this will happen in
space, not because the zoocoenosis is identical to some spatial extent but,
since parts of the coenosis are linked to the plants occupying this space, and
others are related to these first elements of a census. Space, in this situation,
fills a secondary role, but this is still an important role because - in addition
to providing energy sources - it also contains macro- and microclimatic
conditions that, although secondary, still have a profound influence on the
formation of the zoocoenosis.
The measurement of abundance currently uses heterogeneous, and ¬
consequently - incomparable, methods: units of surface or volume, both in
the canopy, counting on leaves, etc. These methods lead to a confusing mass
of data, leading, inevitably, to false conclusions. The abundance of the larval
population of Operophthera brumata can, justifiably, be related to the number
(either surface area or mass) of leaves, but the ants hunting for them cannot
be censused in the same way because they do not search the canopy for the
leaves but for the larvae that are there, and ant abundance will be greatest
where the presence of larvae is high. The abundance of ants can, therefore,
only be related to the number of Operophthera larvae. For example, out of
14600 cherry leaves, 8760 had a single Operophthera larva; on these larvae,