Seed development, germination, and seedling performance of Spartina alterniflora from the upper Bay of Fundy and Northumberland Strait for salt marsh restoration

Abstract

Salt marshes offer essential ecosystem benefits, including improved coastal resilience, increasing the interest in their restoration. In Atlantic Canada, the key engineering species is the saltwater cordgrass, Spartina alterniflora. Effective restoration requires using locally adapted, genetically diverse plant material capable of withstanding environmental stressors. My research aimed to introduce a new approach to salt marsh restoration in New Brunswick by collecting wild seeds and producing S. alterniflora seedlings. From July-November in 2020 and 2021, I tracked flowering and seed development across salt marshes in the Bay of Fundy and Northumberland Strait to identify optimal seed-harvesting periods. Flowering and maturity occurred later in 2020, and Fundy sites were generally 1-2 weeks earlier than the Northumberland sites. Seeds collected in 2020 were cold stratified in two storage treatments, germinated, and grown in a greenhouse. Seedlings were then outplanted, showing strong survival and growth, supporting the use of native S. alterniflora in restoration.