Time series of values of ingenious parameters indicating ecosystem services from European beech andNorway spruce ecosystems at Solling, Germany, were evaluated with respect to resilient or adaptivebehaviour. Studied indicators comprise the use of monitoring data with up to more than 40 years ofobservation on deposition of potential acidity, sulphate (SO4
2−) budgets, exchangeable base cation pools,Bc/Al ratio in soil solution, nitrogen (N) budgets, foliar nutrition as indicated by the foliar Bc/N ratio,and defoliation. Deposition of potential acidity decreased considerably at both ecosystems. SO4
2−budg-ets reveal retention of sulphur in the soils affecting acid/base budgets. Exchangeable base cation poolsdecreased at both ecosystems by about 60%. Bc/Al ratio in soil solution in the mineral soil was mostlybelow critical limits indicating potential toxic stress to tree roots. N retention in the soils decreased fromabout 40 kg ha−1yr−1in the 1970s to currently very low rates of 0–20 kg ha−1yr−1indicating increasing Nsaturation. Foliar Bc/N ratio decreased at the spruce ecosystem indicating possible nutrient imbalances.Defoliation at both Solling ecosystems is on a high level compared to other forests in Germany, but revealsno distinct relation to soil acidification or N saturation. From the selected indicators, SO4
2−and N budgetsreveal resilient behaviour, whereas indicators related to the acid/base status tend to adaptive behaviour.
