|Wesselink, LG; Meiwes, KJ; Matzner, E; Stein, A: Long-term changes in water and soil chemistry in spruce and beech forests, Solling, Germany, Environmental Science Technology, 29, 51-58 (1995)|
With declining sulfur emissions in western Europe, the degree and time scales of reversibility of soil and freshwater acidification are of major interest. We analyzed long-term changes (1969-1991) in the chemistry of bulk precipitation, throughfall water, soil water, and exchangeable base cations in a beech and a spruce forest in Solling, Germany. Time trends in dissolved and exchangeable pools of base cations in the soils were compared with simulations from a simple mechanistic soil chemistry model to identify the processes controlling long-term changes in soil chemistry. In the early 1970s, profound acidification occurred in the spruce and beech soils due to increasing concentrations of dissolved S04. After 1976, atmospheric deposition of SO4 decreased significantly as a result of reduced industrial emissions. Nevertheless, acidification continued in the spruce soil due to declining atmospheric inputs of Ca and Mg and continuously high dissolved SO4 in the soil. In the beech soil, with lower deposition levels, smaller declines of base cation deposition, and a more diluted soil solution, reduced atmospheric inputs of SO4 in the 1980s started off a recovery of the soil‘s base saturation.