Sulfur status of selected European forest soils as dependent on the atmospheric S deposition

Along a transect from the Pyrenees (SP), over the Vosges Mountains (FR), the Black Forest and the Bavarian Forest (D), and the eastern Ore Mountains to the Iser-Mountains (CR) 10 representative forest soil forms derived from granite regolith and 1 developed from gneiss debris (Dystic Cambisols, Leptic and Ferro-Humic Podzols) at montane and high-montane elevation were analyzed for their concentrations and amounts of total sulfur and various S fractions in order to study the impact of the atmospheric sulfur input, increasing from SW to NE, on the soil sulfur characteristics. Soils receiving low S inputs are generally characterized by low amounts of inorganic (especially water soluble) sulfate. Most of their total S amount consists of organic sulfur. With increasing S deposition, the concentrations of total S and C-S and the ratios S-t/C-org, C-S/C-org and SO4-S-tot/C-org in the L-, Of- and Oh-horizons increase. The Aeh- and Ah-horizons of Cambisols and Podzols under different sulfur load do not differ with regard to the S parameters. The B horizons of the northeastern soils affected by high sulfur deposition, however, are markedly enriched with adsorbed and water-soluble sulfate and show comparably high ratios of sulfate S versus dithionite-extractable iron.