Acidification of forest soils on glacial till in Sweden. Soil chemical status and acidification processes in relation to environmental conditions

摘要

A survey study of the penetration of acidification in Swedish forest soils is reported. Twenty-five temporary plots previously used for monitoring of forest production that were established between 1942 and 1964, were revisited during 1988 to 1990. The transects in the South and middle parts of Sweden coincides with the gradients for the atmospheric deposition of acids, mainly H2SO4 and HNO3. It was found that soil acidity tends to decrease from west to east in the south and middle parts of Sweden. In the profiles receiving the highest load of acid deposition, the depletion of base cations is almost complete throughout the profile down to 2.5 m depth. Calculations based on the increase in biomass since the plots were established showed that appreciable biological acidification had occurred at a few sites but no clear geographic pattern in this acidification was found. The biological acidification in spruce stands were considerably higher than in pine stands. 74 refs, 16 figs, 22 tabs