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Florida's
Nature - Wetlands
Wetland habitats originally covered about 60 percent of Florida's
landmass. While much has been lost to agriculture and
development and remaining acreage has been reduced to less
than half of the original amount, Florida still boasts more
wetland acreage than any other state.
Wetlands and the surrounding eco-tone are biologically diverse and
are of
environmental and economic importance to Florida, they store and filter our
water supply while protecting us from floods and buffer
shorelines from storms.
Florida's aquatic
freshwater and marine life, including many commercial and sport
fishes depend on these marshes and various types of swamps as feeding grounds,
nurseries and breeding areas.
Florida's wetlands also provide numerous recreational opportunities for
boating, fishing,
photography and bird watching.
What makes a habitat a wetland?
In Florida, wetlands are defined as areas that are inundated
or have saturated soils for long enough periods of time to
support plants which have adapted to and can grow and reproduce in
flooded conditions or saturated, anaerobic
soils.
Wetlands can form in low lying areas such as depressions or sloughs,
where there
is an underlying strata of
"hardpan" consisting of a mixture of sand and clay or limestone
which slows drainage or where the groundwater level is at
or above the surface of the landscape.
The length of time that these wetland habitat remain flooded is
referred to as the hydroperiod. Hydroperiods vary in length and may
be as brief as a couple of weeks or as long as a year or more. Some
wetlands never dry out completely while others dry only every couple
years or during periods of extended drought.
For a complete technical description of the rules for identifying
and delineating wetlands as set forth by the Florida Department
of Environmental Protection,
click here. (P.D.F.
format)
Freshwater Marsh
A Freshwater marsh may be flooded seasonally or year-round. Marshes
are natures water filters, collecting water and slowly filtering it
through vegetation. This allows suspended particles to settle out,
while plants absorb excess nutrients.
Types of freshwater marshes include Wet Prairies, Depression and
Basin marshes, Floodplain marshes & Bogs.
Common plants include emergent & floating leafed species
such as Cattails, Sawgrass, Pickerelweed, Rushes, Sedges, American
Lotus, American White Water lily.
Pictures - (L) Seasonally flooded shallow marsh within a wet
prairie,
(R) Freshwater marsh in foreground with Water lilies,
bordered by Pickerel weed & Sawgrass marsh with Wet Pine flatwoods in
background.
Wet Prairie
Wet Prairie is a seasonally flooded, shallow freshwater marsh found in depressions, sloughs,
finger glades & on the floodplains or margins of lakes, streams and rivers.
Some of the plants common to Wet Prairies include St. John's Wort, Sedges, Muhly grass,
Sawgrass, Groundsel bush, Wax Myrtle, Sundew, Meadowbeauty, Marshpinks,
& Coreopsis spp.
Wet Prairie
Left - Dry season Center - Wet season
Right - Wet Prairie in a woodland depression.
Cypress Swamp, Cypress Strand &
Cypress Dome
Found on the floodplains of freshwater rivers, lakes and seasonally flooded
woodland depressions/sloughs. Dominated by Bald Cypress or Pond Cypress
sometimes with a mix of other hardwood trees. The length of time that Cypress
stays flooded determines what understory plants are present. There may be
aquatic, emergent and
herbaceous plant species present. A Cypress Dome is named for it's shape with
the older, taller trees in the center and smaller, younger trees on the
perimeter. Strands usually follow a slough
resulting in the strand shape, which is longer than it is wide. The margins of Cypress strands
& domes usually support a higher number of plant species than the interior &
often transition into a Wet Prairie or Wet Flatwoods habitat.
Pictures - (L) Cypress Dome, (C) Interior of a Cypress dome during the dry
season, (R) Cypress Swamp on the floodplain of a freshwater river.
Mangrove Forests & Swamps
Found worldwide from approximately 25 to 28 degrees north and south latitudes,
Mangroves are comprised of 70 or so species which have adapted to life on the
protected shorelines of marine estuaries and bays.
Red,
Black, and White Mangroves are the three species of Mangrove that grow in
Florida. Plants associated with Mangroves include Buttonwood, Saltwort, Glasswort, Christmas berry, Sea-blite &
Saltmarsh cordgrass.
In Florida, mangroves grow south of the frost line with the highest
concentrations of trees found further south. The Ten-thousand Islands on the
S.W. Florida coast is made up of hundreds of Mangrove islets and is a popular
destination for fishermen and birdwatchers alike.
Mangroves are a critical habitat and feeding ground for over 120 animal species.
The Peregrine Falcon, Bald
Eagle, Osprey, Pelican and several varieties of Herons use mangroves for
hunting, nesting or roosting.
Blue claw, Fiddler and Mangrove crabs, shrimps, corals, sponges, oysters,
seahorses and a host of other marine invertebrates also call the mangroves home.
Pictures - (L) Red Mangroves line the Loxahatchee river in South Florida,
(C) Mangroves at low tide, showing stilt roots. (R) This picture shows the dense
tangle of Red Mangrove stilt roots that provide shelter for numerous marine
animals, help to dissipate wave energy and stabilize shorelines in Florida.
Hardwood Swamps
Hardwood swamps consist of various hardwood trees or a mixture of hardwoods and Cypress.
This type of habitat occurs on floodplains &
upland areas that are lower than the surrounding area. Water
hickory, Cypress, Holly, Maples, Oaks, Cabbage
palms and Bay trees, usually with a dense understory of vines, ferns and herbaceous plants.
Pictures - (L) Interior of a hydric hardwood swamp with lush understory growth
(R) During the dry season a small blackwater stream trickles through a mix of
Cabbage palms, Oaks and Maples.
Baygall, Bay Swamp
Perpetually wet areas that receive slow seepage or drainage from
higher elevations, soil is that of a heavy acidic muck and peat with a thick layer of leaf litter. Dominated by Bay
trees, hence the name. Loblolly Bay, Swamp Bay, Red bay, Sweet Bay. Understory plants
include Dahoon holly, Wax myrtle, Fetterbush,
Royal fern, and Cinnamon fern.
Picture - Baygall, Bay swamp
Salt Marsh
Found in the sheltered tidal zones of rivers, creeks and bays. In the southern
part of Florida salt marshes are broken up or replaced by Mangrove
swamps & forests.
The degree of water salinity determines
the dominate plant. Smooth cordgrass in the normal tidal zone and black
needlerush in areas that receive less frequent inundation of
brackish water, such as during occasional extreme high tides and storms. Salt
marsh habitat offer juvenile fish a protected nursery, away from larger fish who
would prey on them. They filter pollutants and trap sediments from storm waters
that would choke offshore reefs and the vegetation also helps stabilize
shorelines, preventing erosion. Salt marshes are a good example of how different
habitats interact as ecosystems.
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Mangrove Ecology,
Silviculture and Conservation
By Peter Saenger |
