We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Surv...