Oldal 155 [155]
OCR
VIII. AGROBIOCOENOSES AND THEIR ZOOCOENOSES Can we speak of agrobiocoenoses at all, and can we call the cultivated areas biotopes, and their animal associations biocoenoses? Several authors reply with a definite “no’, which follows from making “balance” the criterion of a biocoenosis, and separating humans from the elements of the biocoenosis. We have already articulated our opinion about the concept of balance, now we must examine the role of humans. As a preamble, we declare that we consider biocoenosis as any animal association that fulfils the criteria detailed in the chapter on biocoenosis, thus, also associations of cultivated areas. The only concession is that the biocoenoses influenced by humans will be called culture-biocoenoses (Balogh, 1953). When culture-biocoenoses are defined as biocoenoses under continuous human influence, it becomes obvious that there are various degrees of influence, and the anthropogenic factors operating in culture-biocoenoses are active not only in cultivated fields and orchards, but, also — even if in milder form -, in meadows, forests, wetlands and watercourses, causing divergent changes there. We cannot draw a sharp line; humans have an impact wherever they settle. This is a most visible characteristic in forests, where all degrees occur from a minimal maintenance of a natural forest, to establishing a new plantation, including planting non-native species. As we leave a human settlement, where forest disturbance is highest, the impact diminishes with increasing distance. Can we draw a sharp line here and, if we cannot, are we justified in making the definition of a biocoenosis as dependent on human influence, or not? The essence of the biocoenosis is not whether it is under human influence or not, but that it is an association of living things. This association can live, develop and undergo succession in the absence of human influence, and can do so without, or because of, human impact. The only difference is that, in the first case, we do not have to consider anthropogenic factors, while we must in the latter instance. Rammner (1953) has, most recently, considered the question ofa biocoenosis on areas under agricultural cultivation, and he concluded that these cannot be considered biocoenoses. We agree with the author that a biocoenosis is not a random collection of various animals and plants, but an association in
