INTEGRATED ASSESSMENT OF SOIL CHEMICAL STATUS - 2 - APPLICATION OF A REGIONALIZED MODEL TO 622 FORESTED SITES IN SWITZERLAND

A regionalized version of the dynamic, process-oriented, multi-layer s oil chemistry model SAFE was applied to 622 forest sites in Switzerlan d to assess effects of acidifying atmospheric deposition on the soil c hemistry between 1850 and 2050. Simulation indicates that the present day chemical status of Swiss soils is a result of the last 50 years of acid deposition. Indicative soil parameters such as soil solution pH, acid neutralizing capacity, total Al concentration, base cation to to tal Al molar ratio and base saturation consistently deteriorate since the beginning of the 1950s, when acid loads start to increase. The sim ulated adverse evolution of soil chemistry persists until some time be tween 1975 and 2010, and apart from being site-dependent, the turning- point is also dependent on which parameter is considered at which soil depth.