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In a field experiment we analysed the 15N/14N ratios in hot- and coldwater soil extracts, salt extracts (KCl), leachates as well as in the soil vegetation for quantifying the impacts of atmospheric N inputs on soil N dynamics. We simulated moderate and chronically high N inputs and determined the forms, contents, and atom% from December 2001 to November 2002 in a German Scots pine forest stand. A maximum of 90% of the total 15N in the soil was extractable by the KCl, hot- and coldwater soil extraction methods in strongly dependence of the soil horizon. The highest 15N recovery was calculated for the organic layer and the Ah horizon. After one year, only 2% of the added 15N was leached below the C2 horizon (-100 cm), whereas up to 11% were found in the soil vegetation. About 70% of the added 15N was lost by nitrification and denitrification processes during the experiment. [ABSTRACT FROM AUTHOR]