TRANSPORT OF TRACE ELEMENTS IN ECOSYSTEMS OF THE BÄRHALDE WATERSHED IN THE SOUTHERN BLACK FOREST

Abstract

Concentrations of trace elements and macroelements in rainfall, canopy drip, runoff, and soil solution have been determined each week at four free-drained and three hydromorphic sites at an altitude of 1000–1300 meters above sea level in the very humid, cool Black Forest. Among these elements, the turnover of beryllium, cadmium, copper and lead are discussed in detail. Beryllium had the lowest input and the highest output of these four elements. It was primarily mobilized in the mineral topsoil, and only a small amount was readsorbed by humic acids or subsoil or taken up by plants. Lead concentrations were highest in precipitation, but only about 5 percent of the input appeared in the output. Cadmium, Cu, and Pb were all adsorbed by the humus and iron oxide accumulation horizons of podzols and Ockererde. Copper was adsorbed in all soils except podzols, and fixation of Cu was especially obvious in the Ockererde. Cadmium was not highly adsorbed in mineral soil. The recent increase in atmospheric input resulted in an enrichment and rise of turnover for Cd, Cu, and Pb throughout the watershed.