Dataset: N-15 tracer study in coastal marshes of Barataria Bay, LA (v.0.10)
Data files
Jan 04, 2023 version files 8.83 KB
Abstract
The application of isotopic tracers and the subsequent analysis of nitrogen isotope ratios are commonly used to track the spatial and temporal fate of nutrients in both aquatic and terrestrial systems. A substantial amount of work has been completed to determine the nitrogen (N) removal capacity of agricultural, municipal wastewater, and storm water treatment wetlands. However, the fate of N enrichment on varying marsh systems is still not completely understood or predictable. To evaluate relationships between nutrients and plant responses, biogeochemical processes, and nutrient retention and export across varying ecotomes, a full factorial nutrient and sediment field study was implemented in early May 2019, consisting of three different marshes either dominated by Sagittaria lancifolia, Spartina patens, or Schoenoplectus americanus. Each system was labeled with the stable isotope Nitrogen-15 (N15) early in the growing season (June 15, 2019) by injecting calcium nitrate (10 atom % N15) in three installments once per day at mid-tide so as to limit loss of the tracer downward through percolation. A total of 250 mL of label was injected at 10 cm depth for a total of 1.2 g N15 per plot. Data collection occurred on day 5, 15, and 30 following last injection, consisting of species richness and abundance, aboveground biomass, belowground biomass, and soil. Plant tissues and soil were examined to determine the processing and fate of dissolved NO3- in these plant communities.