Middle St. Johns - Florida Department of Environmental Protection

208 Water Quality Assessment Report: Middle St. Johns
Table B.1 (continued)
Community
Percent of
Acres
Type
Basin Area
Wetlands and Open Water
Freshwater
marsh and wet
prairie
42,948.56 3.30%
Cypress swamp 51,176.87 3.93%
Mixed
hardwood
swamp
121,416.26 9.32%
Bay swamp 17,030.29 1.31%
Shrub swamp 21,622.74 1.66%
Open water 117,897.81 9.05% Lakes and streams
Disturbed Lands
Grassland /
agricultural
land
Shrub and
brush land
114,979.28 8.83%
181,894.73 13.96%
Barren land 118,027.40 9.06%
Community Description
These communities are dominated by herbaceous plant species growing on
sand, clay, marl, or organic soils. Common species are pickerel weed,
spatterdock, cattail, and sawgrass. Water depths and inundation regimes
vary. Generally, freshwater marshes occur in deeper areas that are inundated
longer and are characterized by tall emergents and floating-leafed species.
This category also includes portions of freshwater lakes, rivers, and canals
that are dominated by floating-leafed plants. Wet prairies commonly occur in
shallow, periodically inundated areas or are found in scattered shallow
depressions within dry prairies. They are usually dominated by aquatic
grasses, sedges, and their associates.
The dominant overstory tree is either pond or bald cypress. This community
is found along the borders of large rivers, creeks, and lakes or in isolated
depressions.
These swamps occur as either stands of hardwoods or a mix of hardwoods
and cypress. Overstory tree species are black gum, water tupelo, bald
cypress, dahoon holly, cabbage palm, red maple, or sweetbay. Swamps are
commonly found on organic soils along floodplains of nonalluvial rivers,
creeks, and lakes.
The dominant vegetation consists of broadleaf evergreen hardwoods,
including sweetbay, swamp bay, and loblolly bay. This community occurs in
shallow depressions or at the base of sandy ridges where seepage keeps
the soil wet. Soils are usually acidic peat or muck.
Shrub swamps are dominated by dense, woody shrubs or small trees.
Some common species are willow, wax myrtle, buttonbush, and saplings of
red maple, black gum, or other wooded wetland species. Shrub swamps
can be indicative of wetlands experiencing environmental change.
These upland communities consist of very low-growing grasses and forbs.
They are usually found on intensively managed sites such as improved
pastures, lawns, golf courses, road shoulders, cemeteries, or weedy, fallow
agricultural fields. This early successional category includes all sites with
herbaceous vegetation between the stages of bare ground and shrub and
brush, as well as all agricultural fields.
Shrub and brush land includes natural upland communities that have been
recently disturbed (such as clear-cutting commercial pinelands, land
clearing, or fire) and are recovering through natural successional processes.
It is characterized as an early stage of succession for old fields, dominated
by various shrubs, tree saplings, and lesser amounts of grasses and herbs.
Highly reflective areas such as roads, beaches, strip mines, tilled
agricultural sites, and cleared land are included as barren land.
Unvegetated urban areas are also included. Vegetated tracts within urban
areas are mapped by their predominate vegetative cover.