Zur pedochemie des berylliums — untersuchungen einer bodengesellschaft im gebiet des bärhaldegranits (südschwarzwald)

Abstract

The profile distribution of Be is given for a toposequence of podzols, brown earths, stagnogley, forest bog and “Ockererde” (slope gley with infiltrated Al, Mn and Fe). Analysed were the parent rock, fine earth, four fractions of mineral soil (fine skeleton, sand, silt, clay) and the needles of spruce trees. Beryllium is involved in selective weathering processes of elements. Accordingly, the Be-content increases from the fine skeleton to sand, rock, silt and clay, progressively. Through pedogenetic enrichment, Be accumulates in the mica-rich silt fraction. Uptake of Be by spruce is very low even from these acid soils. The accumulation in the needles becomes greater with increasing age. The pedochemical behaviour of Be is very similar to that of Al. Be is incorporated very little in the organic matter cycle, and is therefore not enriched in the soil humus. The brown earth has lost Be, especially in the A h-horizon. In the A e-horizon of the podzol, loss of Be is even greater; the loss is partly offset by Be-enrichment in the B-horizon. In the profiles of depressions, the Be-content is high and is ascribed to lateral flow from the slopes. Be-enrichment is especially high in horizons with a pH of about 5. The Be-balance of the watershed indicates an export of about 10% of the original amount.