This LTREB-funded project will support continued data collection on net primary production and nutrient dynamics in control and fertilized plots of salt marsh vegetation at the former North Inlet LTER site. Stem populations of marsh cord grass have been recorded monthly on permanent plots in two high marsh sites, two low marsh sites, and one experimentally fertilized high marsh site. The existing long-term data on demography, productivity, and sediment chemistry are unique and have led to new insights about the regulation of marsh productivity. Additionally, existing primary productivity data will be supplemented with monthly measurements of sediment respiration. Preliminary data show that sediment respiration has increased in experimentally fertilized plots and that sediment carbon has decreased. These long-term measurements will yield basic information about interactions between belowground and aboveground processes, and a clearer understanding about the regulation of salt marsh primary production and carbon storage in coastal ecosystems. The structure and function of coastal wetlands will change as a consequence of eutrophication and global environmental changes. This research will yield data directly relevant to these issues.
