Tidal wetlands in Nova Scotia: plant community composition and environmental influences across Atlantic coastal, Northumberland/Bras d’Or, and Fundy Shore ecoregions

Abstract

This study assesses tidal wetland vegetation across three Nova Scotia ecoregions: the Atlantic Coastal, Fundy Shore, and Northumberland/Bras d’Or. Field surveys in 2023 (264 plots across 30 sites) were compared with historical data to examine how environmental factors—elevation, inundation values, soil nutrients, and salinity—shape plant communities. Dominant high and low marsh species consistently differed in elevation relative to the Canadian Geodetic Vertical Datum of 2013 across ecoregions, with Fundy Shore vegetation occurring higher than on the Atlantic Coastal and Northumberland/Bras d’Or. Key drivers of plant distribution included inundation frequency, elevation, substrate salinity, and phosphate content. While low and high wetland vegetation was similar across regions, brackish and tidal freshwater vegetation varied more, especially on the Atlantic Coastal and Northumberland/Bras d’Or ecoregions. Southwestern Atlantic Coastal sites supported unique communities dominated by Schoenoplectus americanus and Eleocharis rostellata. Brackish and freshwater wetlands were underrepresented in the Fundy Shore, suggesting the need for an updated baseline to be used for conservation and restoration.