Concluding remarks

Abstract

In conclusion, the following major findings can be stated:

• High deposition loads of air pollutants in the past caused high accumulation rates of the respective substances in the soil; locally base saturation and pH values of the soils were improved, also Ca, S, and N soil stores were increased; as a consequence, humus forms changed.

• In relation to former deposition loads, high output rates still occur from the rooted solum, particularly related to SO42‒, Ca2+, and at Taura — because of subsoil acidification — also Al3+.

• Despite regionally high historic N deposition rates and N input via fertilization no N-losses with the seepage water could be detected.

• The strong reduction of the alkaline deposition loads after reunification of Germany and the still relatively high acid deposition rates locally lead to re-acidification of soils.

• Reduced concentrations of air pollutants in the atmosphere after reunification of Germany led to an improvement of canopy density and foliar tissue of the investigated Scots pine stands.

• The improvement of the photosynthetic potential of the foliage is related to an enhanced growth performance of the trees.</Absttext>