Distribution and Cycling of Major and Trace Elements in Two Central European Forest Ecosystems

Abstract

AbstractConcentrations and annual fluxes of K, Na, Ca, Mg, Al, Fe, Mn, Zn, N, S, P, Cr, Cu, Ni, Pb, Sb, Bi, Cd, Hg, and Tl were measured in the precipitation input to the forest canopy, in precipitation beneath canopy, and in the seepage water below the humus layer and below the tree root zone (output) both in a Central European beech (Fagus silvatica) and in a spruce (Picea abies) forest. Concentrations were determined in an acid loess loam soil from the beech site and in a calcareous little‐weathered loess C‐horizon for the same elements plus Sr and V.When precipitation was passing through the forest canopy, some elements were partially retained (P, Cu, Fe, Zn, Hg, Cr). The flux of other elements increased during canopy passage.Strong retention of Pb and Ni in the organic surface layer (O‐horizon) was found when seepage water passed through it. Within the mineral soil, retention of dissolved elements from the seepage water is observed in the case of K, Ca, Fe, N, S, P, Cr, Pb, Sb, Hg, and Tl.Compared to the unweathered loess, the acid forest soil was nearly depleted of its Ca and carbonate‐C contents. A similar, but less distinct, decrease was found in the total profile (Na, Sr, V, Cr, Cu, Zn), or in the soil surface layer only (Mg, Al, Fe, Mn, Ni, Co). Carbon, N, P, S, Pb, Hg, Bi, and Tl accumulated in the soil surface layer.The input/output balance showed that both forest ecosystems accumulated all elements entering the system with atmospheric precipitation except Al and Mn. The elements Pb, Hg, Bi, and Tl accumulated mainly within the top soil.