Physical, chemical and biological aspects of human impacts on urban soils of Szeged (SE Hungary)

Abstract

Urban soils have generally suffered significant alteration both regarding their physical, chemical, as well as biological properties. Soil samples were taken at 25 sites from horizons of soil profiles located in the downtown and surroundings of Szeged in order to examine diagnostic properties different from natural soils (artefacts, humus content, quality of organic matter, pH (H2O, KCl), carbonate content, nitrogen content). Furthermore, topsoils were taken nearby 9 profiles to survey some basic biological properties (i.e. abundance, taxon diversity, dominance, similarity and MGP ratios) of mezofauna elements (Oribatid mites, Collembolans) and their community structure in the three zones (city, suburban, peripheral). The high amount of artefacts, fluctuating humus and nitrogen levels, the poor quality of organic matter, the high and fluctuating carbonate content, the concomitant variance of pH and modified mechanical properties prove that the urban soils of Szeged have been modified by anthropogenic activities. Surprisingly, it seems that the intermediate suburban zone has a more heterogeneous and stable mezofaunal community structure than the other two.