Ammophila breviligulata Fern. (American beach grass) is a clonal perennial C3 grass native to the shores of the Great Lakes and Atlantic coast of North America from about 35o N to 53o N latitude. The species is a pioneer colonist that introduces a marked surface roughness element to the beach surface, absorbs the energy contained in the saltating sand grains, and initiates dune formation, community development and primary succession. Established populations expand towards the shoreline by producing plagiotropic rhizomes that are fragmented into varying lengths by wave action, transported laterally in water, and then deposited onshore at new locations where they serve as sources of new plants. Seedling establishment is extremely rare and restricted to drift-lines and moist slacks. Two most obvious environmental stresses on the beach and foredunes are recurrent burial in sand and salt spray. Studies showed that below a certain threshold level of burial, the growth of A. breviligulata plants was stimulated probably because of multiple factors, improved soil resources, increase in soil volume, reactive plant growth, and enhanced mycorrhizal activity. Conversely, as soon as sand accretion ceases, there is a marked decline in vigour and density of A. breviligulata populations. Several factors such as accumulation of organic matter, desiccation of culm bases, aging of plants, and infestation by nematodes may contribute to this decline. Upon burial, the culms of A. breviligulata emerged above the sand surface by an increase in the number of nodes and the elongation of internodes. Soon after their emergence the plants produced shootborne roots close to the new soil surface. Ammophila breviligulata plants exhibited moderate to high resistance to salinity. Seawater immersion of shoots and rhizome did not reduce the ability of buds to produce ramets. The species may be classified as a salt resistant glycophyte but not a halophyte.

Key words: American Beach Grass, Ammophila breviligulata, burial, Great Lakes, sand dunes seashore