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OCR
144 IVIL Zoocoenological characteristics 2) semi-continuous, when, in some sampling units (partial areas), some populations are not represented by any semaphoront; 3) discontinuous, when certain areas are not inhabited by the zoocoenosis in guestion, i.e. the zoocoenosis is island-like and clumped in a few parts of the whole area. This coenological dispersion must be distinguished from the dispersion of populations. The latter is often an idiobiological phenomenon and can, likewise, be continuous, semi-continuous or discontinuous; or, depending on the social predisposition of the species, can even be congregated in large numbers (Aphidae). Onto the combination of these differentpopulation-level dispersion characteristics, into which each species brings its own species-specific dispersion, our picture of the coenological-level dispersion can be projected. For example, the fact that the Zabrus tenebrioides beetle has a clumped distribution on a 100 ha wheat field, does not indicate the dispersion type of the Zabritena tenebrioidis catenarium, only that of the species, whose distribution should then be categorised as discontinuous. The discontinuity of this corrumpent population, though, will certainly have an impact on the dispersion of the whole zoocoenosis, given that, on some locations of the occupied area, the semaphoronts linked to the corrumpent element will be missing. Thus, the idiobiological factors manifest themselves in synbiology, that is in the zoocoenosis; the latter must not be viewed through a single population, but always in its totality. The dispersion of individual semaphoront groups can be quantified through censuses of abundance, if these can be related, through a corrumpent population, to a unit of space or volume. 10. Transformatum and gravitas Characteristics related to mass relations are noteworthy mainly in relation to production biology; their zoocoenological importance, at least in terrestrial coenoses, is far from clarified. Today, when our knowledge is so imperfect concerning the mutual relations of zoocoenosis-forming structural elements, of their influence on each other and, not to mention their composition and its stability, it is difficult to imagine that we could assess the mass-related characteristics without grave imprecision. The transformatum (production of animal organic material) expresses the mean total mass by area or volume of a population of the studied zoocoenosis. Gravitas (mass dominance) expresses what percentage of the total zoocoenosis is contained in the given population. These two terms are defined according to Balogh (1953); changing only the word “species” into population, and instead of production, we used the term “transformatum” (see p. 42).
