Vertical and lateral components of soil nutrient flux in a hillslope. 3. Environ

The vertical and lateral components of chemical flux during storm events were investigated in a Typic Hapludult to assess their im-portance in understanding the effects of atmospheric deposition on hillslope sites. Vertical and lateral water flux were calculated from soil water potential data and hydraulic conductivity curves. Through-fall, stemflow, forest floor leachate, and soil solution from the BA, Bt, and BC horizons were sampled and analyzed for SO4, NO3-N, Cl, HCO3, H, K, Ca, Mg, and Na. Total lateral flow as a ratio of total vertical flow averaged 0.23 and 0.30 in the A and BA horizons, respectively, indicating lateral fluxes were an important path of nu-trient movement in the surface horizons. The highest lateral flow occurred in the A horizon during dry antecedent moisture conditions and in the BA horizon during wet antecedent moisture conditions. Fluxes of all ions except HCO3, NO3-N, and H peaked in the forest floor leachate and the BA soil solution, then decreased with depth. Decreases of SO4 flux between the BA and BC horizons could not be explained by the lag of solute movement or by lateral solute losses, demonstrating the system was an effective SO4 sink. A CCELERATED SOIL NUTRIENT LEACHING due tO I~\. acid deposition is an environmental concern. Field studies have examined the effects on forest nu-trient status and nutrient cycling by measuring soil solution concentrations (Johnson et al., 1985; Crona