Incorporation of 35S‐sulfate into phosphate‐extractable S, hydriodic acid‐reducible S (HI‐S), and total S was measured in three horizons of Spodosols from the Huntington Forest, New York and Hubbard Brook Experimental Forest, New Hampshire. After 56 d 35S incorporated into nonwater‐extractable S constituents was 92, 65, 92, 63, 72, and 91% of the total 35S‐activity for the Huntington Forest Oa, Bh, Bsl, and Hubbard Brook Oa, Bh, and Bsl horizons, respectively. Immobilization of 35S‐sulfate into carbon‐bonded S (total S — HI‐S) was the major incorporation pathway in the Oa horizons. Adsorption of 35S‐sulfate (phosphate‐extractable) was most evident in the Bh and Bsl horizons. Incorporation of 35S‐sulfate into ester sulfate (HI‐S — inorganic S) occurred in all horizons. The influence of immobilization‐mineralization and adsorption‐desorption on S dynamics of these forest soils was evaluated.
Sediment cores from lakes in four regions (Adirondacks, Northern New England, Northern Great Lakes States, and Northern Florida) were analyzed for total S concentration. In all regions S concentrations in pre-1900 (1820-1900) sediment were similar and pre-1900 net sediment accumulation rates of S were not significantly different. Sulfur enrichment was greatest in Adirondack lake sediment (Big Moose L., Upper Wallface P., Queer L., and Deep L.), which had total post-1900 S accumulation of 1.1 to 7.4 times pre-1900 S accumulation; post-1900 net sediment accumulation rates of S were significantly greater than the other regions. Sediment from Maine (Little Long P. and Haystack P.) and Vermont (Mud P.) generally had lower S concentration than Adirondack sediments. Sulfur enrichment factors in these lakes ranged from 1.2 to 2.1. There was a positive correlation between contemporary limnetic sulfate concentration and post-1900 net sediment accumulation rates for Adirondack and Northern New England study lakes. Sediment from the Northern Great Lakes States region (McNearney, Andrus, Hustler L. and Dunnigan L.) had similar S concentration and distribution with depth to Northern New England sediment. In two Northern Florida lakes (Mirrow and Fore) sediment showed little variation in S concentration with depth, but L. Mary and L. Barco had higher S in deeper layers (30-55 cm). These different patterns of S distribution among lakes were attributed to differences in limnetic sulfate concentration, organic and inorganic sedimentation, and S diagenesis.
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