Critical loads for sulfur and nitrogen inputs in ecosystems

Critical loads are defined as the ecological limit for the entry of air pollutants into an ecosystem. In the long term, no adverse effects will occur on the ecosystem if critical loads are not exceeded. Critical loads are calculated for acidifying sulphur and nitrogen inputs as well as for eutrophic nitrogen inputs in Austria. Critical loads for acidifying nitrogen and sulphur inputs will be exceeded to 0.6 % of the forest ecosystem area in 2010. The critical loads for eutrophic nitrogen inputs exceed between 31 % and 94 % of the natural ecosystem areas assessed, depending on the method chosen. The significant discrepancy between severe impairment due to nutrient inputs and less adverse effects due to acidification is typical. Since nitrogen is primarily responsible for both problem areas, the reduction of nitrogen inputs should be given greater importance in the future.