This project will continue long term studies of salt marsh primary production that were begun at North Inlet, SC in 1984. Existing long-term data on demography (e.g. stem survival, density dependent growth and mortality, etc.) and productivity of Spartina alterniflora are unique. Stem populations have been monitored monthly on permanent plots that were established in two high marsh sites, two low marsh sites, and one experimentally fertilized high marsh site. There has been significant interannual variation in net aboveground production that appears to be controlled primarily by salinity and sea level anomalies. Existing monthly census of stem populations will be supplemented with measurements of tissue nitrogen, belowground growth and reserves, and additional sediment chemical parameters (pore water ammonium and sulfide concentrations). Existing measurements of per water salinity will continue, and necessary climate and tide data will continue with NOAA support under the National Estuarine Research Reserve Program. %%% 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. The structure nd function of coastal wetlands will change as a consequence of man-made and natural changes in the environment. This research will yield data that are directly relevant to issues of coastal ecosystem management.
