Comparisons of Forest Soils in Relation to Acid Precipitation in Central Norway, South Norway and Schwarzwald in West Germany

1989

5 Tab., 29 Lit. Ang.

Unselbständiges Werk

2693

200037894

Stands of spruce forest from Hoylandet in Central Norway, Sorlandet (Aust- Agder) in South Norway and Schwarzwald (Black Forest) in West Germany have been analyzed as to forest composition and soil conditions. The stands were chosen to represent similar primary site conditions as to vegetation, soil parent materials, climate and time for soil profile development. Total deposition of excess sulphur is estimated to 18 me/m2 year in Hoylandet, 94 me/m2 year in Sorlandet and 264 me/m2 year in Schwarzwald. Chemical analysis of soil samples show consistent differences between the areas. The soils in Schwarzwald have low contents of base cations (Na+,K+,Mg++and Ca++), but high amounts of acid components (Al+++,Fe+++ and titratable H+) in the soil layers. In terms of sum of base cations the soils in Schwarzwald contain about half of that in Hoylandet measured in me/m2. These differences are explained as a result of depletion of base cations and acidification of the soils due to acid rain. The deposition of excess sulphate by acid rain is more than sufficient to explain the observed differences.