A study was done to determine what the differences were between the saltmarshes and to explain why the differences occur. Five sections of marsh were chosen for study. On each of these sections the topography, shear strength, organic matter content, and vegetation characteristics were measured. The external controls identified were fetch length, predominant wind direction, tidal range, and the presence of protective barriers. The results showed that the five marshes fell into two distinct groups, based on similar marsh topography, vegetation, and sediment characteristics.
Group one is wider, and more floristically diverse with distinct high and low marsh sections.
The second group is narrow, dominated by low marsh Spartina alterniflora, and has a more steeply sloping marsh platform. Differences between the two groups reflect different stages in evolution, which appear to be controlled by external factors such as exposure to wave and ice action.