Deposition measurements are a central component of forest monitoring in Germany. They can be used to quantify the pollution of forest ecosystems by air pollutants, such as sulphur or nitrogen compounds. The point measurements of the Level II network allow the identification of trends, provide information on the spatial and temporal variability of the deposition quantities and represent reference points for areal modeling of the inputs, such as those provided by the Federal Environment Agency. Together with data from other survey areas, the deposition measurements enable contributions to be made to numerous other issues. For example, in combination with soil solution data and vegetation surveys, assumptions for calculating critical load limits for eutrophying and acidifying substances can be validated. Last but not least, the joint consideration of deposition measurements, meteorological records, pedological investigations and other surveys allows conclusions to be drawn about the relative importance of these factors for the vitality and growth of trees.