Physiological Advantages for Dominant Dune Species with Climate Warming

Abstract Sand dunes are important barriers to the coastal interior and provide habitat for numerous organisms. Species composition influences the shape and size of dunes, yet recent studies have documented changes in range of native species and increased abundance of invasive species. Warming temperatures are attributed to changes in plant species distributions, yet the effects of varying temperature on the physiology of dominant dune grasses in the southeast US are largely unknown. We characterized how the temperature and light environments affected the physiology of dominant species differing in photosynthetic pathways and compared to field values. Species physiological responses were not fully explained by differences in photosynthetic pathways. Carex kobomugi (invasive C3) exhibited the highest rates of photosynthesis, stomatal conductance (GSW), and electron transport rate (ETR) at 20 to 40 °C compared to native species. Physiology of Ammophila breviligulata (native C3) was negatively impacted at high temperatures, potentially impacting future range distributions, whereas physiological performance was reduced at 25 °C and below in Panicum amarum (native C4). In contrast, Uniola paniculata (native C4) exhibited similar photosynthetic rates to A. breviligulata at most temperatures. These results demonstrate that temperature differentially impacts species physiology and may impact future range distributions with climate warming.