Specyfika i status ekologiczny miasta

Karolewski Marek A.

doi:ISSN 0013-2969

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Title: Specyfika i status ekologiczny miasta

Abstract:

This is an attempt to present results of ecological studies of urban environments. A review of mainly Polish literature is the basis foT presentation of problems concerning: specific ecological character of urban environments, characteristics of town vegetation and municipal fauna communities, regularities of municipal ecological systems, colonization of towns by wild fauna and the specific character of municipal animals populations, characteristics of suburban environments, ecological status of urban environment and the place of man in the ecological structure of these environments.As regards biotic and abiotic conditions urban environments differ basically from natural and other anthropogenic environments and are specific „ecological islands”.Artificial town vegetation — formed from the very beginning — is constantly under the influence of man's activities (Fig. 1), which, amongst other things, is the cause of serious disturbances in the functioning of biotic systems. Isolated municipal greens have various types of vegetation and differ considerably as regards the areas it occupies. The structure and character of vegetation affect strongly the formation of town fauna communities.Town fauna has been studied unevenly and in fragments. Communities of town fauna, and especially the best known town avifauna differ distinctly from wild communities (Table I). With increasing urbanization the number of species decreases at a simultaneous increase in numbers of other populations. In town communities there is ho stability and there are frequent changes in the dominance structure as regards the dominance of one species. Under extreme conditions the number of species and numbers decrease. Quite many populations live in buildings moving towards the centTe where the buildings are close to one another (Table II), whereas other populations leave towns to live in its surroundings.Wild populations colonize in the vicinity of towns because of the attractiveness of this kind of environment. Several populations gradually penetrating the town undergo the synurbization process (Table III) and adapt to life under artificial, much changed conditions.Adaptation of population to specific urban environment is responsible for a number of significant changes in its ecology, biology and ethology, for changes of physiological properties and also perhaps genetic features. Thus separate urban populations are formed which are quite different from populations of the same species (Table IV). Numerous data point also to the simultaneous occurrence in town of wild and typically town population, but the town population colonizes mainly the centre and the wild one is pushed out in the direction of suburbs (Table II).Towns and surrounding areas strongly influence one another. Suburban environments, additonally under the influence of neighbouring natural environments, are very specific both from the point of landscape and ecologically. They are very important as a potential pool of fauna supplying — permanently or periodically — urban environments […]