Effects of acid atmospheric deposition on the chemical composition of loess, clay and peat soils under forest in the Netherlands

In addition to a survey of the soils under 150 forest stands on non-calcareous sandy soils, the chemical composition of the soils under 40 stands on non-calcareous loess soil, 30 stands on non-calcareous clay soils and 30 stands on oligotrophous peat soils have been examined, to assess the current status with repect to acidification and eutrophication, and the provide data for further studies. Only the clay soils are not yet seriously affected by the atmospheric inputs. The loess soils are generally considerably acidified, except the alluvial loess soils. The peat soils show a considerable eutrophication, especially in the topsoil, whereas anthropogenic acidification can hardly be separated from their natural acidity. Most investigated heavy metals show elevated concentrations, both in the humus layer and in the top soil, but serious pollution is not found.