The effect of macrophytes on nitrogen cycling in sediments will be studied. The research will focus on how two nitrogen transformations, nitrification and demitrification, are influenced by the release of oxygen from the roots of submerged macrophytes, from both freshwater and marine ecosystems. Intact vegetated and non-vegetated sediment cores will serve as the experimental systems. Nitrogen transformations will be measured using 15N techniques. At the same time, oxygen gradients near the roots and rhizomes will be measured using oxygen electrodes. The results of this study should contribute in important ways to our understanding of the role of macrophyte beds in nitrogen cycling in aquatic ecosystems. The facilities at the University of Maryland's Horn Point Environmental Laboratories are excellent for this type of research. Dr. Kemp is a fine researcher who will be able to advise Ms. Caffrey as she works on this project.
