Inorganic nitrogen processing and assimilation in a forested wetland

The ability of a forested wetland in the lower Mississippi valley to process and assimilate inorganic nitrogen was investigated. Nitrogen-15-labelled ammonium and nitrate-nitrogen were added at elevated levels to field plots. Emissions of labelled nitrogen and nitrous oxide and labelled ammonium and nitrate-nitrogen in flood-water from the plots were measured during a 67 d study period. Forested wetland soil could remove significant amounts of ammonium and nitrate from surface water by assimilation and denitrification processes. The site was a bottom-land hardwood forest in the Spring Bayou Wildlife Management Area. Flooding from the Mississippi and Red rivers occurred in late autumn and winter.