Creating a New England Salt Marsh Sediment Profile: Methods and Implications for Climate Change Mitigation Strategies

Salt marshes and other blue carbon systems (mangroves, sea grasses) sequester large amounts of carbon primarily through sedimentation and therefore naturally aid in climate change mitigation. However, disturbances caused by anthropogenic activity (agriculture, ditching, invasive species and construction) are leading to New England salt marsh habitat destruction. The loss of this carbon sink could result in the system becoming a carbon source contributing to climate change rather than abating climate change. In this study, Vernier sensors were used to collect both in situ soil temperature, soil moisture, and soil salinity) and in discrete sediment samples (soil pH) weekly from June 2018 to June 2019 at the Neponset River Salt Marsh (Boston, Massachusetts) to observe seasonal variations in sediment characteristics. Samples were obtained from one location dominated by Spartina patens (S. patens) and at a second location dominated by Spartina alterniflora (S. alterniflora) to understand if plant zonation and/or distance from the creek channel affect sediment properties. Preliminary results show that, across both sampling locations, soil temperature, soil moisture, and soil salinity significantly differed by each season while soil pH did not change across seasons. Conversely, soil pH, temperature, and soil salinity did were not significantly different between sampling locations while soil moisture was different in the autumn and the winter only across sampling locations in the same season. Final results from this study along with climate change implications of the findings will be presented.