Acid Deposition and Nutrient Leaching from Deciduous Vegetation and Podzolic Soils at the Turkey Lakes Watershed

Mean annual ion concentrations and ion fluxes in precipitation induced by contact with a maple–birch forest and soil were determined for 1981–85 at the Turkey Lakes Watershed (47°03′N, 84°15′W). Neutralization of atmospherically deposited H + was effected by the canopy and mineral soil. Sulphate was an important counter-ion for K + leached from the vegetation. Acid deposition had a minor impact on the quality of stemflow and forest floor percolate, which were enriched in K + and Ca 2+ mobilized in association with organic anions. Calcium and Mg 2+ were leached from the mineral soil in association with SO 4 2− and NO 3 − . Sulphate was derived largely from acid deposition, and NO 3 − from both precipitation and nitrification of native soil N.