Geologic and pedogenic effects on heavy metal distributions in forest soils from the Cserhát Mts and the Karancs area, NE Hungary

Abstract

Distribution and partition of heavy metals (Cr, Co, Cu, Ni, Pb and Zn) in four forest soil profiles characterized by different parent materials and similar pedogenic processes were studied to distinguish the inherited characteristics from those caused by pedogenic processes in soils at natural background level of these metals. Distributions of total heavy metal amounts are determined mostly by the parent material, while the repartition of heavy metals among the soil components is regulated mainly by pedogenic effects. Heavy metals bound to residual phases are almost solely inherited from the parent material. Combined effects are the clay illuviation with different clay mineralogy due to the differences in parent material, as well as the calcareous subsoil resulting from inheritance and secondary carbonate precipitation. In the studied samples the organic matter plays the most decisive role in binding heavy metals. A significant proportion of lead is bound to it, but it also has an effect on copper and nic...