Association Between Marsh Vegetation and Soil Drainage Class Across the Delmarva Peninsula

• Isabelle Vavala, Environmental Science, University of Delaware
• Josephine Petrak, Environmental Science, University of Delaware
• Lauren Hollinger, Geography, University of Delaware

• Pinki Mondal, Geography and Spatial Sciences, University of Delaware, University of Delaware

Marsh vegetation is influenced by a diverse set of environmental conditions such as hydrology, salinity, and soil characteristics. Understanding how dominant species are distributed across different soil types can improve wetland management. This study examined the occurrence of four dominant marsh plant species across different soil drainage classes derived from the Soil Survey Geographic Database (SSURGO), ranging from subaqueous to excessively drained. Over 200 field observations for marsh plant species were collected during site visits across 10 coastal counties in the Delmarva Peninsula (Delaware, Maryland, and Virginia). Observed species included: Spartina alterniflora (Smooth cordgrass), Spartina patens (Saltmeadow cordgrass), Phragmites australis (Common reed), and Juncus roemerianus (Black needlerush). Field observations were spatially joined with USDA SSURGO soil data in ArcGIS Pro to assign a drainage class to each species observation. Species and soil drainage distributions were mapped, and the data were imported into JMP, where a frequency table was created and later formatted using Excel. Overall, we found that the majority of observed species were located in areas with poorly or very poorly drained soil. Additionally, Phragmites australis was found in a wider range of soil drainage classes compared to the other species studied.