The influence of the wind direction and plants on the variability of topsoil magnetic susceptibility in industrial and urban areas of southern Poland

摘要

Volume magnetic susceptibility (kappa) was measured on the soil surface and in the vertical topsoil profile within a 300 km(2) area located in an urban-industrial conurbation. The results were compared to plant species compositions in the forest storeys, elevation above sea level, and terrain geomorphology. The content and mineral composition of the magnetic fraction were determined in the soil horizons. It was found that the extent of the area with enhanced topsoil magnetic susceptibility was similar to the dominant wind direction (south-west). Enhanced kappa values were observed for the soil at the forest margin on the leeward side of the emitters as well as at sites located on exposed local elevations (>= 10 m). There were no significant correlations between species composition of the forest stand and soil surface kappa value (measured both with and without forest litter). Soil covered with deciduous trees-mostly ash (Fraxinus excelsior L.)-demonstrated higher kappa values than soil under coniferous tree species. However, our results suggest that this parameter is not controlled by individual tree species, but rather depends on distance from emission sources, intensity of magnetic particle emission, and meteorological conditions (prevailing wind directions and dynamics).