Vegetation change in herbaceous Carolina bays of the Upper Coastal Plain: dynamics during drought

While hydrologic condition is not the only driver of plant species composition in herbaceous wetlands, it is considered to exert the strongest influence on species composition. The vegetation of thirteen herbaceous Carolina bay wetlands of the South Carolina Upper Coastal Plain was sampled during inundation; the seed bank of four of these bays was also sampled. In 2002, toward the end of a multi-year drought, vegetation was re-sampled and compared to the previous data sets. Bays generally had higher species richness by 2002, but the increase was not significant. All bays lost aquatic species while grasses increased dramatically in occurrence. Woody plants also established. Results were consistent with cyclic models of Carolina bay vegetation dynamics. There was little relationship between species that were in the vegetation and their occurrence in the seed bank. The vegetation of herbaceous Carolina bays appears to be resilient, cycling as climate-driven wetland conditions oscillate.