Oldal 31 [31]
OCR
§ The concept of biocoenosis | 29 Links among these structural elements elucidate the community relationship that unites these organisms as a biocoenosis. Irrespective of considering the traditional triad, or the above-detailed elementary categories, as the essence of a biocoenosis, it is certain that the concept must refer to an overarching unit, expressing some sort of totality that is also physically recognisable. Observing the development of the concept of biocoenosis, we can clearly see that a large majority of authors aim to express something similarly extensive and, apparently, want to avoid its use for a small segment of a habitat. By excluding the “community” interpretation of the biocoenosis, we squarely fall into this camp ourselves. Delimiting a biocoenosis is, however, not an easy task, and from the desire that this concept be restricted to a larger, physiognomically recognisable unit, it follows that the additional concepts of biological equilibrium and its consequent homeostasis became included in most definitions. These will be dealt with in a separate chapter; at this stage, only the following needs to be acknowledged. As only the producent organisms can generate organic material, it is without doubt that the basis of all biocoenoses can only be formed by producents. The essential point of a biocoenosis is not being, or not being, in equilibrium, but whether it contains producent organisms; in their absence, a biocoenosis cannot be formed nor sustained. Additionally, as with life itself, the biocoenosis, as a form of life, has development potential, starts from a small beginning, and gradually expands. It follows from the principle of development, that all biocoenoses start when a producent appears in each space. Therefore, once a producent is present, we see the start of a biocoenosis that is gradually enriched by the other structural components, and will reach a climax state permitted by edaphic and climatic constraints, according to the rules of succession. Definitions that emphasise the equilibrium criterion contain the basic error that they totally ignore the principles of development/evolution, and that such a definition can only refer to an advanced, complex, climax association, containing all the component structural elements. An island just emerged from the sea, or the bare soil of a fresh landslide, is gradually colonised by organisms. When can we name such an area an “independent” biocoenosis; when can we apply to them the concept of an equilibrium and the ability to self-regulate? There are no certain answers to these questions. A biocoenosis is, therefore, an association of plants and animals that is gradually formed by various structural elements, but always around producent organisms, its components are in living interactions with each other, and it is formed in a definable space of the biosphere, as a physiognomically recognisable unit. In theory, all biocoenoses start with the tiniest of producents that make the soil suitable for a richer community of organisms, but it also follows from the concept of the biosphere, that the influences from neighbouring, more
