Abstract: Halophytic plants thrive in high saline environments due to their physiological adaptations. Examples of adaptations include sequestering salt in specialized glands, selective ion exclusion, and ion secretion. Furthermore, these adaptations allow halophytes to exhibit phenotypic plasticity in response to a changing environment at different spatial and temporal scales. The governing thresholds of how much an individual plant or population can respond to salinity levels are not well understood. The ability to be phenotypically plastic could indicate the invasibility of a species when environmental conditions pass a survivorship threshold. The goal of this project is to provide preliminary data on trait variability in Spartina alterniflora (also known as Sporobolus alterniflorus; Smooth Cordgrass), a dominant grass species in South Carolina salt marshes, along multiple transects in the North Inlet-Winyah Bay National Estuarine Research Reserve, Georgetown, South Carolina. Trait variability data will elucidate this species’ range of morphologies along salinity gradients, an environmental variable that is changing due to saltwater intrusion and increasing storm surge. Previous studies have identified trait variability for S. alterniflora in other locations, however, site-specific measurements are necessary to capture local edaphic conditions. Here we document trait variability in regional populations and identify those traits that show the potential to change in response to different edaphic conditions. Describing/quantifying trait variability in our regional populations will allow us to predict the persistence likelihood of this species under future edaphic conditions and if there is a survivorship threshold. Overall, this research will improve our fundamental understanding of salt marsh resilience to global change and their contributions to South Carolina’s ecosystem services and natural resource production.
