A frequently invoked aim of wetland restoration is to alleviate nitrogen loading to surface waters by promoting natural denitrification in flooded wetland soils.  This approach assumes that microbial denitrification is controlled by anoxic conditions, and that flooding alone will stimulate this anaerobic process.  Yet denitrification in anoxic soils may also determined by the supply of labile carbon or nitrate, or by rates of nitrification.  In this study, we focused on a 400-ha former agricultural field that is to be re-inundated in spring 2007 and was densely planted with native wetland tree species in 2005.  We established two transects across an expected flooding gradient, and we examined controls on denitrification in samples from surface soils in 39 locations.  We hypothesized that in this previously fertilized landscape, available C would be likely to limit denitrification.  We found high and highly variable potential denitrification rates, with differential limitation of denitrification by C or N availability, depending on topographic setting.  These denitrification results, along with nitrification potential, C and N mineralization rates, are used to predict the likely patterns of and limits to denitrification that will result from the upcoming conversion of this agricultural field to a forested riverine wetland.