Analyses of nitrogen flow from aquatic environments to terrestrial environments: ratio of 15N/14N ratios of Ammophila breviligulata in dune ecosystems

Abstract

With the possibility of nutrient flow from aquatic ecosystems to terrestrial environments, dune grass Ammophila breviligulata from the Sturgeon Bay, MI shoreline were analyzed for 15N/14N isotopic ratios to determine if there is a flow between these two ecosystems. Three transect lines were sampled 10 meters apart and parallel to the shoreline, along with a terrestrial and aquatic control samples. All samples were analyzed by Stable Isotope Mass Spectrometer, and 15N, percentage of 15N/14N composition, and total nitrogen composition were measured for all samples. The preliminary results indicate that there is an input of 15N from the aquatic ecosystem into the immediate terrestrial shoreline.