The Role of Beach Nourishment on the Success of Invasive Asiatic Sand Sedge

摘要

Beach nourishment, or artificial addition of sediment to a beach, a common practice for rebuilding beaches for recreation and storm protection, can have positive or negative effects on the flora and fauna of dune communities. There has been little work exploring the consequences of nourishment on the impacts of invasive plant species that thrive on dunes. In this study, we explored the impacts of nourishment on the invasiveness of Carex kobomugi (Asiatic Sand Sedge) in secondary dune communities composed primarily of Ammophila breviligulata (American Beachgrass) and Solidago sempervirens (Seaside Goldenrod) at 3 study sites at Island Beach State Park in New Jersey, testing the hypothesis that nourishment promotes sedge invasion. Dune communities were subjected to 5 burial depth treatments in similar to 15-cm increments ranging from 0 (control) to 60 cm (similar to 24 inches) burial. Growth responses were monitored by quantifying emergent individuals and by harvesting all aboveground biomass at the end of the season. Physiological responses were evaluated using an infrared gas analyzer to quantify photosynthesis rates. Burials lead to a reduction in community diversity and native species biomass, while favoring the invasive species. In addition, Seaside Goldenrod within invaded communities exhibited significantly lower photosynthesis rates than those individuals in non-invaded communities. The results suggest that nourishment will promote Asiatic Sand Sedge invasion to the detriment of native dune species.