Litterfall, Stemflow, and Throughfall Nutrient Fluxes in an Alluvial Swamp Forest

Abstract

Nutrient deposition to the forest floor of an alluvial swamp in the North Carolina Coastal Plain was measured and compared with other wetland and upland forests. For the alluvial forest, annual litterfall was 6428 kg dry mass/ha of which 63% was Nyssa aquatica leaves. Nutrient flux to the forest floor in kilograms per hectare per year for litterfall and aqueous sources (stemflow plus throughfall), respectively, was 2779 and 91.5 for organic carbon, 72.77 and 10.31 for N, 5.38 and 1.55 for P, 7.19 and 921 for S, 21.1 and 11.96 for K, 45.1 and 15.31 for Ca, and 17.0 and 7.60 for Mg. Most of these values are near the upper range or higher than those reported for mature upland temperate forests and still—water swamps. The particularly high values for nitrogen and phosphorus in the alluvial forest may be a consequence of fluvial sources, whereas nutrient sources for upland forests and still—water swamps are restricted to atmospheric inputs and weathering.