Forms of Cotton Marsh in Delaware
The Cotton Marsh form is the most common Reed Tidal Marsh signature in Delaware and is so named because of the cottony appearance. Two forms are most prominent, but expression can fall anywhere in between. The two distinct forms are dirty cotton marsh and light cotton (clean) marsh. The density of the stems generally determines how easy it is to identify for either of the marsh types.
Dirty Cotton Marsh
The density of stems determines the distinctiveness of this marsh. Marsh that is low in density is often hard to see and identify and if there is a another vegetation community involved, it is even harder. Tall forms of North Atlantic Low Salt Marsh and Irregularly Flooded Eastern Tidal Salt Shrub can both look like Reed Tidal Marsh. However, Irregularly Flooded Eastern Tidal Salt Shrub has a “speckled trout” appearance that can serve to separate it. Beware of the combination of these two communities (will cover in a later post). Below are some pictures of the various types in 2007 aerial imagery.
Imagery with Ground View
A comparison of a 2007 aerial imagery signature of dirty cotton marsh and a ground view of the same marsh in the Red Mill Creek watershed is provided below. The location at the edge of the overall marshland is a typical location for Reed Tidal Marsh in high salinity locations.
Light Cotton Marsh
Light cotton marsh tends to only have a dense form and has a cleaner appearance. It has a tendency to appear on the edges of marshland in higher salinity water. North Atlantic High Salt Marsh and piles of dead reed grass can look very similar. To differentiate, look for an appearance of stem height. Be careful if there are piles of dead reed grass as North Atlantic High Salt Marsh can form on the piles. Below is a picture of Light Cotton Marsh on 2007 aerial imagery from Little Creek watershed.