Supporting Data for: Spatial and temporal variation in drivers of saltmarsh eco-geomorphic evolution: Field insights from the St. Lawrence Estuary, Canada

Six MSR accelerometers, or "mini buoys" , were deployed at 30 different locations over the various campaigns, measuring acceleration (g) along the sensor's y-axis. This dataset captures transitions from dry to flooded conditions (point measurement). SEDIMENT DYNAMICS -- Sediment dynamics were investigated along two transects perpendicular to the saltmarsh edge, each with 5 sampling stations.

Deposition (D) (sediment mass) was measured on acrylic tiles over periods of appr. 1 month, and siphon samplers were used for measurements of suspended sediment concentration (SSC) in tidal floodwaters. VEGETATION -- Two types of vegetation surveys were conducted with 0.5 m x 0.5 m quadrats. Random quadrat surveys were performed for species distribution (quadrat percent coverage by species).

Repeated (seasonal) quadrat surveys along two marsh edge transects (10 m intervals) consisted of percent coverage and stem length and diameter measurements for dominant species. GEOSPATIAL DATA -- RTK data for instrument/sampling locations was collected using Emlid Reach GNSS receivers. Root-mean-square error for positioning (easting, northing, elevation) was always < 3 cm.

All RTK GPS data was collected in the following coordinate system: • Horizontal Datum : NAD83 (CSRS) • Projection : UTM19N • Vertical Datum : CGVD2013 • Geoid Model : CGG2013