Combining multiple isotopes and metagenomic to delineate the role of canopy nitrification at ICP forest sites. (Invited key note speaker)

Acid atmospheric deposition is decreasing since the 1980s, mainly due to reduced sulfur dioxide emissions. But the input of acidic nitrogen compounds remains still at a high level. In Rhineland-Palatinate (Germany), where a high percentage of the forest area is located on poor bsoils with low buffer capacity, liming actions were performed in order to compensate the negative consequences of the acid deposition. In 1988, three study areas with control plots and different liming treatments from 3 to 15 t dolomitic limestone ha-1 were established to monitor soil acidification and to investigate the effect of liming regarding acid compensation