Comparative aspects of sulfur mineralization in sediments of a eutrophic lake basin

The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is <50% complete, which is consistent with the dominance of organic sulfur (>80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average 7 mmol/m per day. On an annual basis, this rate is 19-fold greater than net rates of organic sulfur mineralization and 65-fold greater than sulfate ester hydrolysis.