Gradienten von Bodeneigenschaften im Randbereich kleinflächiger Waldstandorte des östlichen Münsterlandes

Gradients of soil characteristics at fringe areas of small forest habitats of the Eastern Münsterland In four habitats of the Eastern Münsterland transects, perpendicular to south-western exposed forest fringes, were investigated. Subject of the investigation was to determine statistically detectable gradients of the following soil properties: C/N-ratio, pH- and pH_KCl-value, ECEC standardized with respect to the C_org content and the EDTA-extractable fraction of Pb and Zn in the humic layers Of and Oh. Towards the inner forest, the C/N-ratio increasingly expands, the pH-values and ECEC decrease and the Pb-contents increase. Zinc does not show a trend concerning a gradient. Differences between the C/N-ratio of the Oh-layer and the Of-layer are obviously a consequence of the N-deposition. Higher pH-values at the forest fringe appear to be due to the deposition of dust from the field clod. The interception deposition caused by the coniferous trees in the inner part of the forest effects lower pH-values than that of the deciduous trees at the forest fringe. The Oh-layers have a higher Pb content than the Of-layers because of the specific kind of sorption concerning this heavy metal and the change of the situation of deposition during the last years. For the same reasons the Of-layers have a higher zinc content than the Oh-layers. The results show that the forest fringes of the investigated habitats, in a range of 5—10 m, work as a buffer zone for laterally deposited substances.