Spartina alterniflora is a dominant plant species of salt marsh habitats along the South Carolina coastline. Because of historical and recent destruction and die-off of Spartina marshes, restoration of Spartina marshes remains a top priority. Restoration efforts have greatest success when Spartina genotypes are selected that thrive in restored areas, but our understanding of this genetic variation is poor. This project addressed that gap.
Using genotypes from more than 11,000 single-nucleotide polymorphisms from 340 Spartina plants, our study distinguished Spartina among biogeographic zones separated by hundreds of miles, river systems within a single state separated by tens of miles, and tall vs. short-form Spartina separated by tens of yards. The results have important consequences for restoration managers, as there is a strong likelihood that adaptation to local salinity, temperature, and soil conditions is commonplace. When plants are moved away from their sources, even those that are a few hundred feet away, the survivorship, growth, or reproductive fitness of these plants likely is lowered, making restoration efforts less productive and more inefficient than they could be.