Formulation of an organic carbon trajectory over a 10-year period on a restored spoil island in south-central Florida

Abstract:

Long-term monitoring of restoration projects aims to determine long-term sustainability and stability of restored systems. In coastal wetlands, one indicator of restoration of ecosystem function can be seen with organic matter (specifically carbon) accretion. SL-15, a spoil island in Fort Pierce, Fl was restored in 2005, and has been monitored for return to natural condition over the last 10 years.. To assess sediment carbon accretion, sediment cores were collected in a set of eight plots, located on the SL-15 mangrove island and the surrounding seagrass recruitment area. These were analyzed for organic carbon, microbial biomass carbon, extractable carbon, and total nitrogen. The biogeochemical data collected in the previous year was compared to data collected in 2005-2007. Vegetation surveys were also completed to show the build-up of organic material in accordance with vegetation shift over the 9-year period. From this information, a trajectory has been formulated on organic carbon accretion and vegetation shift from the time of orginal restoration activities. By comparison to control sites nearby, realistic estimates of time required to reach natural levels of carbon and vegetation community structure can be calculated..