Prechtel, A: Release of stored sulphur from acid soils under decreasing sulphur deposition in Bayreuther Institut für Terrestrische Ökosystemforschung (BITÖK): Bayreuther Forum Ökologie, Selbstverlag, 107, 1-102 (2004) | |
Abstract: High anthropogenic sulphur deposition to forested catchments enhanced the natural soil acidification and caused acidification of freshwaters and severe ecosystem damage. Part of the atmospheric sulphur was stored in the catchments’ soils mainly as inorganic sulphate (SO4) or as organic sulphur (Sorg). High anthropogenic sulphur deposition to forested catchments enhanced the natural soil acidification and caused acidification of freshwaters and severe ecosystem damage. Part of the atmospheric sulphur was stored in the catchments’ soils mainly as inorganic sulphate (SO4) or as organic sulphur (Sorg). In regions where previously stored sulphur is released, reversal of water acidification can be delayed for decades. To answer the questions about the reversibility of anthropogenic acidification of waters and of ecosystem recovery, the degree and the dynamics of SO4 release from the soils’ sulphur pools have to be studied. Knowing the relevant soil sulphur pools and understanding the mechanisms of SO4 release from those pools is essential for predicting the timescales of the reversibility of acidification. As part of the EU research project RECOVER:2010 the response of sulphur dynamics in European catchments to decreasing SO4 deposition was evaluated, soil sulphur pools in the organic and inorganic sulphur fractions of eleven European catchments were studied and the role of Sorg for sulphur release from the catchments was evaluated. The future SO4 stream concentrations in the Black Forest catchments Schluchsee and Villingen were simulated with the model MAGIC. In times of decreasing sulphur deposition excess mineralization of Sorg can contribute to the net release of sulphur from the catchments. Excess mineralization (mineralization > immobilization and plant uptake) was investigated and quantified in an in situ incubation experiment in the forest floor of a Norway Spruce stand. |