Homann, P.S., M.J. Mitchell, H. VanMiegroet and D.W.
Cole. 1990. Organic sulfur in throughfall, stemflow and soil
solutions from temperate forests. Canadian Journal of Forest
Abstract: In the assessment of S cycling in forest ecosystems, solutions passing through the forest are normally analyzed for inorganic SO4; other forms of S are rarely considered. In this study, organic S (estimated as the difference between total S and SO4-S) was measured in canopy and soil solutions from eight forest stands spanning a broad range of overstory and soil types. Organic-S concentrations varied among the different types of solutions and among the forests, with values ranging from 0 to 50 mol S.L-1. Organic S was < 10% of total S in precipitation, 5 to 54% in throughfall, 1 to 50% in stemflow, 16 t046% in O-horizon solution, 11 to 21% in A- or E-horizon solutions, and 0 to 29% in B-horizon solutions. Organic s was positively correlated with organic C and organic N in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) soil solutions and in Douglas-fir stem flow (r2 = 0.68 to 0.96, p < 0.001). Inclusion of solution organic S in nutrient cycling budgets can alter estimates of S transfers within forest and S transport out of some forest ecosystems.