S. Mahunka szerk.: Folia Entomologica Hungarica 54. (Budapest, 1993)

FOLIA ENTOMOLOGICA HUNGARICA ROVARTANI KÖZLEMÉNYEK LIV 1993 p. 131-145 Spruce as spider-habitat in urban ecosystem. IL Bioindication role of foliage-dwelling spiders By Cs. Szinetár (Received February 12, 1993) Spruce as spider habitat in urban ecosystem. II. Bioindication role of foliage-dwelling spiders. - The characteristics of spruce-living spider community were examined in this paper, on the basis of collections in 1991 (Szinetár 1992a). Introduction Species richness, species diversity, guild composition, change of seasonal guild composition, guild diversity and frequency of certain families for the analysis of community characteristics in 18 biotopes, were examined in relation to the regions of the town, the average trunk diameter (and age) of the examined spruce trees, and the lead content of the pine needles. Correlation was found between the trunk diameter of trees and species richness (r=0.69 p<01) and between lead burden and the guild diversity (r=-0.906 p<01). The relative common frequency of the Theridiidae family shows an important growth proceeding towards the town centre (N-S transect). The species of Salticidae family are nearly absent from the town centre, and their frequency was extremely low in the industrial district and in the district with heavy traffic. Further examinations are necessary to prove the assumed connections. The presence (occasionally swarming) or absence of various species of animals indicate changes in their environment caused by antropogenic effects (Kovács et al. 1986). Factors affecting individuals and populations manifest themselves in one form or another at the ecosystem level, too. Indication and monitoring at the cenosis and ecosystem level can only answer such basic questions of ecology as, for example, how man changes the living world by transforming and polluting it (Podani 1986). The examination of animal cenoses living in urban ecosystems can provide information at the same time on the properties of these cenoses and also on the changes of the quality of human environment which take place in certain places and periods of time. The examination of the urban fauna with an ecological approach was, in fact, started only in the last decade. The findings of a number of research work going on in many cities of the world have already been published (Kovács et al. 1985, 1986, Klausnitzer 1987, 1988). It has been proved for a number of species of animals that relatively rich species cenoses can develop in the spontaneous fauna of urban biotopes. In this connection, an excellent example is set by the spiders, which cover in an extraordinarily differentiated way and with a comparatively high number of individuals and species nearly the whole of the urban areas (Schaefer 1973, 1979, Klausnitzer et al. 1980, Koslowski et al. 1980, Krzyzanowskaetal. 1981, Sacher 1983, Platen 1984, Thaler et al. 1987). In Hungary, the examination of the spider fauna of urban biotopes