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122 IVIL Zoocoenological characteristics
considering their structural base, and they can be corrumpents, sustinents,
or intercalary catenae. An example of the first is Ceutorrhynchitena maculae¬
albae, of the second, Apiditena mellificae, and the third one Eccoptogastritens
rugulosi.
The number and kind of constituent coeti is a characteristic of a zoocoenosis.
If, among the constituent populations, there is only one linked to the plant
energy source, such a zoocoenosis can only be a catena. According to the
coetus association of this population, it can be a corrumpent, sustinent or
intercalary catena; by the number of coeti, it can be an initial, or a precedent,
zoocoenosis. If, at the base level, there are more populations linked to the
same plant as an energy source, the zoocoenosis is a precedent one, and it is
ranked as a catenarium. If the plant base is composed of multiple species,
the zoocoenosis can be considered a plenary one, with a rank of presocium
or supersocion. A community that, apparently, has only a single coetus,
should, in theory, be considered a catenarium or presocion. The supersocion
occupies a special position because, sensu stricto, it does not have a sustinent
coetus. A supersocion is not linked to a specific plant community, nor to
initial links or pre-existing catenaria, but assumes the pre-existence of plenary
presocia, with the plant community serving as its energy source. The sustinent
elements, therefore, as an indispensable part of presocia, belong to the
supersocion, as its first trophic level is the presocium itself, or its totality.
2. Coetus value
The coetus value must appear among the characteristics of zoocoenosis,
because the populations with multiple coetus values can increase the linkages
between the members of the zoocoenosis, and can have a profound influence
on its formation. The greater the coetus value a semaphoront group represents,
the more independent it is from the needs of other semaphoront groups;
thus, the lower the need for association, and it can fit easily into various
zoocoenoses. Certain species of Formicidae, due to their coetus values of 2
or 3, can occur practically everywhere, provided that the abiotic conditions
are suitable. Birds that live on insects in the summer, and seeds during the
winter, can be constant in a biotope, while swallows, having a single coetus
value, must move once insects become scarce.
The coetus value is an important zoocoenological characteristic because
the populations with higher coetus values are members of more widespread
zoocoenoses, and they can have a profound influence on the changes and
sustainability of various zoocoenoses, even if they are, themselves, uncommon
populations.