Ocena gleb Starego Miasta Szczecina jako potencjalnego siedliska leśnego z zastosowaniem Indeksu Trofizmu Gleb Leśnych

The aim of this study was to evaluate the soils from the Old Town in Szczecin (NW Poland) as a potential forest habitat using the Forest Soil Trophism Index (ITGL). For this purpose, six drillings were made, from which the samples of anthropogenic materials were taken. The method of soil material collection for the study did not allow the determination of bulk density required to calculate Soil Trophic Index – the indicator currently used in forest science. The methods commonly used in the soil sciences were used to determine the following properties of the soil samples: texture, pH in H2O, pH in KCl, electrical conductivity (EC), organic carbon content, total nitrogen content, base capacity (BC) and total content of Zn, Pb, Cd, Ni, Cr, Cu and Hg. It was found that the soils from the Old Town in Szczecin were alkaline and contained higher amounts of salts and heavy metals (especially Pb and Zn) than natural soils. The degradation degree of these soils was not significantly enough to prevent the succession of vegetation when anthropic pressure ceased. The ITGL values were high, in the range of 38.9−44.5, because of the presence of organic carbon in whole soil profile, which was also rich in nitrogen, high values of pH in H2O and base capacity. The ITGL values indicated the hypertrophic character of soil materials and potential habitat of the fresh broadleaved forest. After the colonization of tested area by pioneer species of trees, one expects the dominance of beech, oak, maple and linden, i.e. species frequently occurring in the immediate vicinity and at the same time the species constituting of potential vegetation for the Baltic Natural−Forest Province.