Oldal 91 [91]
OCR
§ The formation of the presocium, the habitat association | 89 a broader category, with more extensive energy needs, occurs above them. This is the presocium. A presocium cannot exist if there were no species with more extensive stadia, which extend to all semaphoront groups. Their associated obstant and intercalary elements, by necessity, also extend to whole groups of oecuses or biotopes. Among the eucoen catenae and catenaria, there are semaphoronts that do not belong to any of them, yet neither are they peregrinant elements, because they have trophic connections to the plant cover as well as with similarly dispersed other populations. The presocium is the association composed of such populations. If they did not exist, the catenaria would continue to exist without them, which clearly indicates their status as independent categories. Yet such tichocoen or acoen elements are present, with their associated obstant and intercalary elements; they form a wider associational category above catenae and catenaria, the presocium. For the tichocoen and acoen obstant elements, most of the catenaria of the biotope constitute energy sources and, without them, they could not persist. Thus, they are linked to several catenae; their fate depends on them but, at the same time, they also exert an influence on these catenae. Hence, the formation of the presocium, an associational category above the catenarium. Its foundation is formed by those sustinent, intercalary and corrumpent elements (see Elton’s (1927) “key industries”) that are present in the whole biotope, and are connected to obstant and intercalary populations of similarly wide distribution. § THE LIMITS OF ANIMAL COMMUNITIES. THE CONCEPT OF SUPERSOCION The fact that the different semaphoront groups of the same species fit into various animal associations, and the different populations have contact with other different elements in these associations, creates exceedingly complex interrelationships (see Elton, 1927), that can be represented by using connection diagrams (Tischler, 1951); this makes conceptualising the limits of animal communities very difficult. This leads to consideration of the question posed earlier (see p. 31): how can we draw the limits of animal associations? Based on the discussion so far, one reply is evident: to delimit animal associations in space, in a manner as resolved for plant associations, is impossible. Neither the biotope levels, nor oecuses, nor the limits of the biotope can be perceived as if they were also borders of animal associations. We have seen that individual groups of semaphoronts can change bioroph, oecus or biotope, according to their ecological needs (Nagy 1944; Bej-Bienko, in Tschegolev, 1951; Tischler, 1950; Bej-Bienko and Mishtschenko, 1951). This fact is not changed by the existence of populations that occur only in
