Processes influencing the chemical composition of the O-horizon of podzolsalong a 500-km north-south profile from the coast of the Barents Sea to the Arctic Circle

Large-scale regional processes influencing the chemical composition of the O-horizon of podzols have been studied along a 500-km-long north-south prof ile from the coast of the Barents Sea in N-Norway (North Cape) to the Arcti c Circle in northern Finland. Precipitation (composition and amount) appear s to be the major factor determining the chemical composition of the O-hori zon, followed by vegetation (especially the change from the tundra and suba rctic birch forest to the boreal forest zone). This results in distance to coast having an important influence on pH and concentrations and fluxes of over 20 elements in the O-horizon along this profile. A high local variabil ity of several elements, especially some important nutrients, indicates tha t other small-scale processes also play an important role. While there are signs that elements displaced from surficial soils accumulate in the C-hori zon, the composition of the soil parent material (bedrock, Quaternary drift ) has relatively little influence on the chemistry of the O-horizon for mos t elements. (C) 2000 Elsevier Science B.V. All rights reserved.