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70 | II. Biotope and animal associations
A merotope does not include a full zoocoenosis, but this is not its criterion
- those are detailed above. The fauna of a gall can develop as a special
community, yet it cannot be an oecus, because it constitutes a microbiocoenosis
only with its oak tree.
This appraisal of the merotope is different from Schwenke’s (1953), who
claims that a merotope is the spatial component of a merocoenosis, and it
differs from a biocoenosis in its lack of equilibrium. In our opinion, fields of
cultivated crops are not merotopes but oecuses, and these oecuses form a
biotope, an arvideserta.
Consequently, the name of a unit that is smaller than a biotope but still
independent can only be the oecus, the only term suggested for the smaller
units of the biotope that clearly reflects a synbiological approach.
The oecus is a physically existing part of the biotope, formed by the locations
used by different developmental stages of certain populations. A leaf, a head
of wheat, a cadaver of a deer is not an oecus for the consumers/parasites
feeding on them. And as the biotope is a space + its plant cover, this criterion
should be held valid for the smallest part of the biotope, thus none of the
above examples can be an oecus, even less a biotope. The oecus is not a location
where a semaphoront can be found, but the reproductive space of interdependent
populations. If we define a zoocoenosis as a coalition of populations, living
in a biotope, then its smallest unit should be of sufficient size for whole
populations. A single leaf cannot be an oecus, because it can support perhaps
a few semaphoronts, thus a fraction of the population in question. A single
poppy plant, or a lone apple tree is not necessarily an oecus, because the
poppy or the apple tree is necessary to allow the colonisation of the biotope
bya certain zoocoenosis. The oecus is therefore the totality, or at least a bigger
group of these individual plants, on which groups of populations that require
these plants can live, or where populations are dependent on them as their
primary life condition. A single plant can be an oecus, if it stands alone (such
as a single rose bush on the meadow).
Therefore, the division of a biotope into oecuses does not mean that it a
convoluted patchwork, and there are not as many oecuses as there are
individual plants. When studying one poppy plant or one oak tree, I do not
study the oecus of populations linked to these plants, only a segment of the
oecus. The more such segments I study, the more detailed will be my overall
impression. The fact that the examination of the whole oecus may exceed
our research resources does not change the validity of the above statement,
but only attests the relative value of the results obtained.
In a plant association, therefore, the different oecuses intersperse in a
multi-coloured kaleidoscope. The more homogeneous (by species spectrum)
a plant association, the fewer are the oecuses, and its zoocoenosis will be
more characteristic. The plant components belonging to an oecus should not
be seen as individuals, but as sources of energy, to which specially adapted
populations are linked.