Critical loads for sulfur and nitrogen inputs into ecosystems

Critical loads are defined as the ecological load limit for the entry of air pollutants into an ecosystem. In the long term, there will be no negative impact 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. The critical loads for acidifying nitrogen and sulfur inputs will be exceeded in 2010 on 0.6% of the ecosystem area of forest. For critical loads for eutrophic nitrogen inputs, between 31% and 94% of the assessed near-natural ecosystem areas will be exceeded, depending on the chosen method. The significant discrepancy between severe impairment due to nutrient inputs and less impairment 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.临界负荷（critical loads）被定义为空气污染物进入生态系统时的生态负荷限值。长期来看，若未超出临界负荷，则不会对生态系统造成负面影响。奥地利针对致酸化硫、氮输入以及富营养化氮输入开展临界负荷计算工作。2010年，奥地利境内0.6%的森林生态系统区域超出了致酸化氮与硫输入的临界负荷限值。针对富营养化氮输入临界负荷，依据所选用的评估方法，已评估的近自然生态系统区域中，有31%至94%的区域超出了临界负荷。养分输入引发的严重生态损害与酸化作用引发的较轻损害之间存在显著差异，此类现象具有典型性。鉴于氮是这两类环境问题的核心诱因，未来应进一步强化氮输入削减工作的重视程度。