Application of the model nucsam to the Solling spruce site

The NUtrient Cycling and Soil Acidification Model (nucsam) was applied to a spruce site at Solling, Germany, within the scope of a workshop on comparison of forest soil atmosphere models. Simulated trends and dynamics in the concentrations of SO4, Al and base cations and in pH between 1970 and 1990 compared favourably with time series of measured data during that period. Dynamics and concentrations of NO3 in the subsoil were overestimated. tion results for the period 1990–2090 for two deposition scenarios showed ongoing acidification (pH decrease) of the soil at the present acid load and a rapid response of soil solution chemistry to reduced acid input, but there was a long time delay before favourable AlCa ratios were reached.