摘要：Abstract Flooded swamps in the Atchafalaya River basin, Louisiana, USA, are thought to be a major mechanism for removing excess riverine nitrate that may be causing hypoxia in coastal Louisiana. Two denitrification methods, the 15 N 2 flux and acetylene inhibition technique, were compared and evaluated. Sediment samples were collected from three baldcypress swamp sites located within the Atchafalaya River basin. Highly 15 N-labeled (61.7 at.%) and unlabeled nitrate (100 mg NO 3 –N L −1 ) were applied to the floodwater of separate sets of sediment cores. Denitrification potential was measured 2, 6, 10, and 16 days after nitrate addition. Two days after nitrate addition, no significant differences in denitrification rates were observed between methods. On days 6, 10, and 16, denitrification measured by the 15 N 2 method was higher compared to the acetylene inhibition procedure. When significance was observed, 15 N 2 denitrification was approximately 5.3 times greater.
关键词：denitrification; 15N2 flux method; acetylene inhibition technique; Atchafalaya River Basin
