Greenhouse Growth of Native American Beachgrass (Ammophila breviligulata) and Invasive Asiatic Sand Sedge (Carex kobomugi) Under Competition

Abstract

Worldwide, dunes buffer peripheral coastal areas from destructive abiotic elements of erosion and storms. Vegetation is a major element of these systems as roots bind sand and thereby, stabilize dunes and shoots promote dune growth. The dunes of the Mid-Atlantic U.S. are stabilized by two alpha species that compete for space and resources-native American Beachgrass (Ammophila breviligulata) and invasive Asiatic Sand Sedge (Carex kobomugi). Despite the importance of these species, today many of the biological and physiological factors underpinning their competition remain poorly understood. Therefore, we conducted a 7 week greenhouse competition study with transplanted A. breviligulata and C. kobomugi ramets. We manipulated substrate amount and salt spray as treatments in a factorial-designed greenhouse experiment. Despite ample acclimation prior to testing and appropriate abiotic conditions throughout, we had very low survivorship for both species. This was especially true for C. kobomugi, which may be largely intolerant of wet substrate conditions. We performed microscopy to begin to understand the morphological and physiological differences that could have drive differences in our survival rates. Our results provide information useful for the design and uses of future attempts at conducting coastal vegetation transplant studies.