MS Candidate, University of Connecticut
Assessing Salt Marsh Greenhouse Gas Fluxes by Planting Treatment Across Salinity and Elevational Gradients
Conference Travel Grant Type 2
“Management interventions involving sediment addition are applied to tidal marshes to raise the marsh elevation, reduce inundation frequency, and support wildlife habitat and carbon-based functions. Sediment addition alters marsh salinity and inundation regimes which are both linked to carbon cycling. The response of greenhouse gas emissions to sediment additions, however, is understudied. We leveraged a recent sediment addition project that created 14 experimental hummocks (mounds of sediment that varied from 1.15 – 1.71 meters above sea level) that were planted with different native grass species combinations and densities in Stratford, Connecticut (USA) to investigate how carbon gas fluxes varied along elevational and salinity gradients, and vegetation type. We quantified CO2 and CH4 emissions (2023, 2024) and net ecosystem exchange (2024) using static flux chambers from 140 plots subjected to varied sediment addition depths and planting treatments. Our preliminary findings suggest that CO2 emissions from experimental hummocks were influenced by elevation, salinity, and vegetation communities, whereas CH4 fluxes were net positive but not well explained by studied parameters. Results will be synthesized to inform salt marsh carbon storage considerations for future conservation interventions involving sediment addition.”