Net accretion requires that gross community production exceed community respiration in the marsh.
It is not clear how increased tidal flooding will affect the balance of production and respiration. This site is normally not flooded except during high spring tides in the summer, although flooding is more frequent during winter. Water was pumped from the adjacent Phillips Creek onto the marsh during all daytime high tides. Treatments at the site included an unbordered control, a flooded site with wood border to retain pumped water, a bordered control, and a bordered, wrack-covered site. The borders allowed drainage of water at a slow rate.