“…Throughout the eastern USA, the dominant floral composition of many salt-marsh systems is threatened by alteration. Invasive species including reed grass (Phragmites australis) may invade wetlands, spread, and reduce openwater habitat (Caffrey 1996, Broyer & Varagnat 1998, and/or replace dominant macrophyte species through natural habitat (Sinicrope et al 1990, Havens et al 1997 or anthropogenically derived (Rice 1996, Havens et al 1997 disturbances. Substantial declines in Spartina alterniflora areal coverage have occurred in the USA due to encroachment into mesohaline estuarine areas by P. australis (Rice 1996, Havens et al 1997), a species typically thought to be native to oligohaline wetlands, including those of North America (Niering & Warren 1977, Orson et al 1987.…”