Northern cordgrass prairie is an herbaceous community in which standing or moving water is present most of the year, and usually at least part of each day. This is the approximate amount of time needed for vegetation to achieve high enough density to carry fire. When adequate fuel protrudes above the water surface and weather conditions are conducive to fire spread, fires are propagated whether there is aboveground water or not. The length of time this pulse of nutrients affects the marsh depends on local hydrology and weather. When marsh fires consume litter, accretion of sediments may be slowed.
Black rush produces large amounts of belowground biomass which serves to consolidate marsh surfaces.
The effect of fire on marsh vegetation depends on a number of factors including community composition, season of burning, water level, and postfire rainfall and hydrology. Marsh species are killed by hot, dry-season fires due to destruction of shallow roots. The dominance reversal is temporary, however. In 2 or 3 years saltmeadow cordgrass, which has a higher density potential, regains dominance over bulrushes. Other species grow faster than black rush after fire and may therefore replace it.