Plant Life
The types of vegetation found in each region of the wetland are based on what stage of creation/deterioation is occurring there.  The dynamic nature of the deltaic cycle leads to rapid changes in soil stability, salinity, and subsequently vegetation type in the active zone of the marsh.  The remainder of the marsh is much more stable and exists along a salinity gradient.  The marshes begin with the barrier islands and move inland to the bottomland hardwood swamps.
salt meadow cordgrass
water elm
A majority of the Louisiana coastal wetlands are classified as intertidal marshes.  Intertidal marshes are the most abundant landform on the coastal plain, covering approximately 10,192 square kilometers.  Intertidal marshes consist of salt, brackish, and freshwater vegetation types with the species richness increasing with freshness.  This is due to only a few species being able to tolerate the stresses of both flooding and salinity.  The vegetation found in the coastal marshes can be loosely categorized into groups based on location within the marsh.  Many species overlap into different the different zones especially along tidal creeks or raised landforms.

   

Barrier islands:  typically low and sandy with poorly developed dunes.  The vegetation consists primarily of  salt tolerant xeric grasses and succulent herbs on the dunes grading into salt marsh vegetation on the inland and Gulf sides.  Some ancient barrier islands exist in the Chenier plains and used to be home to Live oak forests that have mostly been lost to subsidence and development.

Smooth Cordgrass:  Present in highly saline regions with wave action, most common on seaward edge of barrier islands
smooth cord grass
Wiregrass:  Most common on higher land on barrier islands
wiregrass
Saltwort:  Very salt tolerant, often found in low spots on and around barrier islands where evaporation leads to high salt concentrations
saltwort
Glasswort:  Found both on barrier islands and mixed in with grasses in the salt marshes.  Likes low, alkaline, salty locations
glasswort
Black Mangrove:  rare, but found along the edges of the barrier islands.  Growth is very stunted due to high frost intolerance
black mangrove
Live oak:  Large populations were once found on ancient levees and other elevated landforms in the Chenier plain.
live oak


smooth cord grass
Salt Marshes:  Found at the coastal edge of the wetland complex and cover approximately 1650 acres.  They are characterized by daily tidal flushing that is also behind the creation of bidirectional stream channels throughout the tidal marsh area.  These streams have slightly elevated banks which are rich in vegetation and extend further into the brackish marsh.   The marsh is almost completely composed of smooth cordgrass with minor contributions from other species including black mangrove


Brackish marsh:  Found in approximately 4704 acres of the Louisiana coastal wetlands and are characterized as having salinity levels between 1-10 parts per thousand.  Intermediate brackish marshes contain many freshwater plants that are able to tolerate occassional spikes of brackish water.  The soil characteristics range widely between those of the salt and fresh marshes.  The marshes are particularly affected by subsidence due to the presence of wiregrass which require substantial sediment deposition in order to not sink.   
Saltgrass:  Found in brackish areas on inland side of barrier islands and along the outer edges of deltaic formations.  Is present in both fresh and salt marshes as well.  Has special salt exclusion glands on leaves as well as roots adapted to penetrate thick hard clay soils.
saltgrass
Salt Meadow Cordgrass:  Most dominant vegetation type in brackish region of wetlands.  Can outcompete all other species unless natural burning or grazing occurs.
salt meadow cordgrass
Wiregrass
wiregrass



Freshwater marsh:  Covers 3,829 square kilometers.  These marshes are strongly influence by seasonal flows of the freshwater sources.  They form in accreting, sediment rich, high energy environments.  Freshwater marshes are dominated by maidencane and arrowhead and it is estimated that 70% are actually floating mats of vegetation.  Over time, woody species such as wax myrtle will colonize these floating mats, causing them to sink and allow for recolonization by open water plants.  The portions of freshwater marsh that are not floating are more affected by flooding and area therefore slightly less productive.
maidencane
Maidencane:  Dominant vegetation type in freshwater marshes and in cane zones adjacent to levees, well adapted for living in floating mats due to thick and extensive roots accounting for 75% of total plant biomass
cattail
Cattail:  Dominant vegetation in nutrient rich portions of freshwater marsh
arrowhead
Arrowhead
alligatorweed
Alligatorweed:  Found in deeper pools of fresh water
phragmites
Phragmites:  Most common on higher ground with fresh water, tolerant of some salt spray
waxmyrtle
Waxmyrtle:  Shrub found further inland
groundsel tree
Groundsel Tree:  Shrub which prefers growing along open water
sandbar willow
Sandbar willow:  Found along high points in the upper freshwater marsh.  Commonly grows on ancient oxbows, levees and sandbars
buttonbush
Buttonbush:  Commonly found at the mouth of streams entering the marsh

Forested Wetlands:  Found at the landward edges of the freshwater marsh and along the main river channels feeding the coastal wetlands.  Mainly found in swamp and bottomland forests.  Much of the higher and therefore drier land was converted to agriculture centuries ago.  The swamps have anaerobic soils, greatly limiting biodiversity.  The bottomland forests are much more diverse but are only loosely linked to the coastal wetlands through hydrology.  Levee forests are fingers of forest which extend into the marshes along ridges of high ground formed by ancient levees.
Water Elm:  Found in floodplains subject to high flooding frequency, very intolerant of salt
water elm
Black Willow:  obligate floodplain species, requires poorly drained soils
black willow
Water Hickory
water hickory
Water  tupelo:  Found in deep-water swamps
watertupelo
Baldcypress:  Most common inhabitant of deep-water swamps
baldcypress
Hackberry:  Common tree found in soils that are not saturated throughout the year
hackberry




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