Relative Stability of Plant Communities in a South Carolina High Salt Marsh

Published:

Dec 2012

Author

James O. Luken

Additional Authors

ABSTRACT The high marsh in southeast Atlantic coast salt marshes forms a relatively small but ecologically important transition zone between low marsh and the terrestrial shoreline. However, long-term trend data from high marshes are limited to a few studies. Permanent plots established in a high marsh near Waties Island in northeast South Carolina were measured for plant coverage from 2002–2010. At the beginning and at the end of the study, four groups of plots were identified: mixed indicated by Borrichia frutescens, Distichlis spicata, and Fimbristylis castanea; Juncus indicated by Juncus roemerianus; Salicornia indicated by Salicornia virginica; and Spartina indicated by Spartina patens. Ordination of the 2010 plot data and soil analyses produced clear separation of the groups along a single dominant axis with Salicornia and Juncus groups at the high end of a salinity gradient and the Spartina group at the high end of soil organic matter gradient. Comparison of plots classified in 2002 to the same plots in 2010 suggested both stability and change, depending on community classification. Salicornia and Spartina groups were stable. The mixed group experienced a switch in dominance from Distichlis spicata to Borrichia frutescens, whereas the Juncus group had gradually declining importance of Juncus roemerianus and gradually increasing importance of Borrichia frutescens. These data represent patterns and trends in a system and time period not affected by development or influenced by high intensity disturbance, and can be used as a reference for other high marshes in the immediate area experiencing environmental change.

Keywords

High marsh, Myrtle Beach, permanent plots, salt marsh, South Carolina, vegetation pattern, Waties Island.