Trace gas fluxes from tidal salt marsh soils: implications for carbon–sulfur biogeochemistry

Abstract. Tidal salt marsh soils can be a dynamic source of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), well sulfur-based trace disulfide (CS2) dimethylsulfide (DMS) which play roles in global climate carbon–sulfur biogeochemistry. Due to the difficulty measuring coastal ecosystems (e.g., flooding, salinity), our current understanding is based on snapshot instantaneous measurements performed during daytime low tide) complicates ability assess role these for natural solutions. We continuous, automated soil gas fluxes throughout growing season obtain high-temporal frequency data provide insights into magnitudes temporal variability across rapidly changing conditions tidal cycles. found that CO2 did not show consistent diel pattern, CH4, N2O, CS2 were highly variable with frequent pulse emissions (> 2500 %, > 10 000 4500 % change, respectively), DMS only occurred midday changes 185 %. When we compared continuous discrete (during daytime, at tide), comparable those from but misrepresent DMS, CS2. Discrepancies between measurement result differences calculating sustained warming potential (SGWP), mainly by an overestimation CH4 when using measurements. The high accurate calculation budgets use blue accounting earth system models.