THE INFLUENCE OF FOREST STAND AND ORGANIC HORIZON DEVELOPMENT ON SOIL SURFACE MEASUREMENT OF MAGNETIC SUSCEPTIBILITY

摘要

Topsoil magnetic susceptibility measurements (K) are used for the fast and effective assessment of soil pollution by heavy metals, the result of industrial and urban dust deposition. Those areas with a high content of anthropogenic magnetic particlesin the soil, which as a result exhibits enhanced topsoil magnetic susceptibility, are areas potentially contaminated with heavy metals. While taking the measurements and during further data interpretation it is important to include some additional sampling factors that can influence the measured value. The aim of this study was to verify the hypothesis of the influence of a forest stand on the magnetic signal measured in forest topsoil, as well as the influence of the thickness of the organic layer on the surface K measurement. The study was based on data from 830 regional measurements. Furthermore, 620 values measured at a local site were used to validate the results obtained using the regional data set. The results showed that soil surface magnetic susceptibility measured in deciduous forests and in deciduous with coniferous admixtures was statistically higher than those measured in coniferous forests. The data also revealed that thick organic horizon slightly decrease the K value measured on the soil surface. However, there is no direct relationship between the measured K values and the occurrence of a tree stand, instead there is a more complex influx of natural (pedological, geological) and methodological (measurement preferences) features.