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Time series of values of ingenious parameters indicating ecosystem services from European beech and Norway spruce ecosystems at Solling, Germany, were evaluated with respect to resilient or adaptive behaviour. Studied indicators comprise the use of monitoring data with up to more than 40 years of observation on deposition of potential acidity, sulphate (SO 4 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. SO 4 2− budgets reveal retention of sulphur in the soils affecting acid/base budgets. Exchangeable base cation pools decreased at both ecosystems by about 60%. Bc/Al ratio in soil solution in the mineral soil was mostly below critical limits indicating potential toxic stress to tree roots. N retention in the soils decreased from about 40 kg ha −1 yr −1 in the 1970s to currently very low rates of 0–20 kg ha −1 yr −1 indicating increasing N saturation. 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 reveals no distinct relation to soil acidification or N saturation. From the selected indicators, SO 4 2− and N budgets reveal resilient behaviour, whereas indicators related to the acid/base status tend to adaptive behaviour.

Forest liming is a common measure to counteract soil acidification. In forest practice, lime is applied to the forest floor where it changes the chemical properties. However, little is known about the depth impact of liming and the depth translocation of lime components. To investigate the long-term impact of forest liming, several study plots have been established in the 1980s in Germany in stands with different site conditions. We analysed soil chemical data obtained during the last 28 years from 45 of the study plots. We examined the depth impact of liming and predicted the main factors responsible for the increase in Calcium (Ca) and Magnesium (Mg) stocks after liming in the mineral soil using multiple linear regression analyses (MLR). Stocks of Ca and Mg as well as base saturation (BS) showed a strong depth gradient with significant differences between limed and control plots down to 40 cm of the mineral soil. About 65–70 % of applied Ca and Mg were recovered in the forest floor and the upper 40 cm of the mineral soil. BS in 0–40 cm increased by a mean of 11 %. MLR models could explain 48–74 % of the variation in mean changes of Ca and Mg in 0–10, 10–20 and 20–40 cm soil depth when soil and climate variables, amount of applied lime and years after liming are included in the model. After testing the model robustness with a cross-validating procedure, we concluded that these models might be applied to many regions in Central Europe with comparable soil and climate conditions and thus, have widespread application.

In a forest stand lime is commonly applied to the forest floor to neutralize acidity and to improve buffering capacity of soil by the addition of carbonate and other anions of weak acids. This is expected to cause major chemical changes in the forest floor. In this study, different liming materials, equivalent to 60 kmol c Ca 2+ +Mg 2+ ha −1 , were applied to the forest floor of a spruce stand. The limes were dolomite, mixtures of dolomite and calcite or chalk, and silicate industrial slag lime (‘Huttenkalk’) of varying particle size combinations. Two years after lime application, salt extractable Ca 2+ and Mg 2+ was measured in the forest floor using a sequential percolation method. This method allowed the assessment of Ca 2+ +Mg 2+ present on exchange sites by distinguishing between the amounts released upon dissolution of residual, undissolved liming material. In all cases there were major changes in exchangeable content of Ca 2+ and Mg 2+ in the L+F layer, whereas changes in the H layer were small. Differences in the effects of liming materials on the litter layer were attributed to their texture, the contents of Ca 2+ and Mg 2+ and the associated anion (carbonate or silicate). High content of exchangeable Ca 2+ and Mg 2+ was observed in the forest floor when liming materials were of high Ca and Mg content and of fine texture. The sum of exchangeable Ca 2+ +Mg 2+ in the forest floor increased from 7 kmol c ha −1 (control) to 17–26 kmol c ha −1 after liming and accounted for 15.5–31.5% of Ca+Mg applied. This increase in exchangeable Ca 2+ and Mg 2+ of L+F layer indicates large amounts of lime may be required to ameliorate mineral soil at depth, and that the content of these cations will partly determine future lime requirement of the spruce stands.

Lime and wood ash may be useful to improve acidic forest soils. A field experiment was conducted in a pine stand on a sandy podzol at Fuhrberg, Germany, which involved an application of dolomitic lime (3 t ha-1) with three replications or wood ash (4.8 t ha-1) without replications on the forest floor. During the 2 yr study period, lime affected the soil solution composition only slightly. Ash had a marked effect on solution chemistry of the mineral soil at 10 cm and the pH values dropped temporarily from 3.7 to 3.1. Nineteen months after the treatments, exchangeable calcium in the organic layer and mineral soil increased by 222 (lime addition) or 411 kg ha-1 (ash addition) and exchangeable magnesium increased by 101 (lime addition) or 39 kg ha-1 (ash addition). After ash addition, no marked change in heavy metal content was found below 4 cm of the organic layer. In the ash treatment, the potassium concentration of the 1-yr-old pine needles increased from 5.6 to 5.9 g kg-1. This study suggests that ash fro...

Addition of wood ash to acid soils will affect the soil chemistry of forests in a number of ways which were assessed for a pine stand in northern Germany. A field experiment was carried out in a fifty-year old pine stand on a sandy Podzol at Fuhrberg (Luneburger Heide, Lower Saxony/Germany) which involved depositing wood ash (2.4 t ha—1) on the surface. Soil solution chemistry was investigated monthly at different depths for 24 months. Prior to and 19 months after the ash addition, exchangeable cations and amounts of heavy metals were determined at different depths. Two to four months after addition of wood ash, maximum mean concentrations in the soil solution of Ca were 240 μmol l—1 at 0 cm (surface of mineral soil) and 100 μmol l—1 at 100 cm and of K 980 μmol l—1 and 140 μmol l—1, respectively. The pH values in soil solutions dropped temporarily by 0.3 units at 0 and 10 cm depth. Nitrate concentrations increased at all depths and maximum mean concentration was 230 μmol l—1 at 100 cm. Concentrations of Pb and Cr in soil solution did not change significantly (p < 0.05) after ash addition. Concentrations of Cd and Zn increased significantly at some depths but stayed well below the legal limit for drinking water and below the limits given by the German recommendation for soil conservation. Nineteen months after ash addition, the cation exchange capacity (corrected for the release of cations from the ash) of the upper 6 cm of the organic layer was almost doubled and amounts of exchangeable Ca and Mg increased significantly in the upper 8 cm of the organic layer. Amounts of Zn were increased in the entire organic layer, but changes were significant only in the upper 4 cm. The results of this study suggest that ash from untreated wood (using modest additions) may be recommended for amelioration of forest soils. Einfluss von Holzasche auf die Bodenchemie bei einem Kiefernbestand in Norddeutschland Ausbringung von Holzasche auf saure Boden beeinflusst die Bodenchemie von Waldern vielfaltig, welches fur einen Kiefernbestand in Norddeutschland untersucht wurde. Ein Feldexperiment wurde in einem funfzigjahrigen Bestand auf einem sandigen Podsol bei Fuhrberg (Luneburger Heide) durchgefuhrt, wobei Holzasche (2,4 t ha—1) oberflachlich ausgebracht wurde. Die Zusammensetzung der Bodenlosung wurde monatlich in verschiedenen Tiefenstufen fur 24 Monate untersucht. Vor und 19 Monate nach der Ascheausbringung wurden die austauschbaren Kationen und Schwermetallvorrate in verschiedenen Tiefenstufen untersucht. Zwei bis vier Monate nach der Aschegabe wurden maximale mittlere Konzentrationen von Ca (240 μmol l—1 in 0 cm und 100 μmol l—1 in 100 cm) und K (980 μmol l—1 in 0 cm und 140 μmol l—1 in 100 cm) gefunden. Die pH-Werte der Bodenlosung nahmen temporar um 0,3 Einheiten in 0 und 10 cm ab. Die Nitratkonzentrationen nahmen in allen Tiefen zu, und die maximale mittlere Konzentration war 230 μmol l—1 in 100 cm. Die Konzentrationen an Pb und Cr in der Bodenlosung anderten sich nicht signifikant (p < 0.05) nach der Aschegabe. Signifikante Zunahmen wurden fur die Zn- und Cd-Konzentrationen in einigen Tiefen gefunden, aber die Werte waren erheblich niedriger als der Grenzwert fur Trinkwasser bzw. als die Empfehlung nach der Bodenschutzverordnung. 19 Monate nach der Aschegabe war die Kationenaustauschkapazitat (bei Berucksichtigung der Kationenfreisetzung der Asche) in den oberen 6 cm der Auflage annahernd verdoppelt und die Mengen an austauschbarem Ca und Mg waren in den oberen 8 cm der Auflage signifikant erhoht. Die Zn-Vorrate nahmen in der gesamten Auflage zu, signifikant aber nur in den oberen 4 cm. Die Ergebnisse dieser Studie zeigen, dass Asche von unbehandeltem Holz (bei Verwendung masiger Dosen) geeignet zur Amelioration von Waldboden sein kann.