The effect of landscape and groundwater discharge on salinity and Spartina alterniflora biomass in the creekbank zone of a developing tidal marsh A. Christy Tyler Abstract Porewater salinity interferes with Spartina alterniflora growth to the extent that the interannual trends in productivity may be the result of salinity fluctuations caused by changes in mean sea level.
Salinity is a function of landscape and position in the marsh.
In concert with the ceiling placed on plant growth by nutrient limitations and redox potential, salinity adds a spatial aspect to the window of conditions for optimum Spartina production. Salts are removed from the sediment by flushing out of the creekbank, or by dilution from fresh groundwater input. In narrow fringing marshes, the inland portion of the drainage area is much closer to the marsh edge than in other types of marshes, so that the type of area that is drained is more important. Groundwater discharge through the system was estimated for each site at slack low tide, when the water table is static. The mean salinity over the 1995 and 1996 growing seasons is 26.8 ppt for Y1, and is 36.4 ppt for Y2.