KUCHLER TYPE DESCRIPTION
 Kuchler Type: Southern cordgrass prairie


PHYSIOGRAPHY : 
Topography is mostly flat to sloping [4]. The type has many lakes,
bayous, and canals and occurs along the Gulf Coast.  There are many
natural levees and tidal channels, but artificial levees and tidal
channels have altered some of the natural topographic features [2].


CLIMATE : 
This area is characterized by mild winters and hot, humid summers [13].
Tides from the Gulf of Mexico influence many areas of the southern
cordgrass prairie.  Maximum tide fluctuation is 26 inches (66 cm),
dropping to 2 to 3 inches (8 cm) per day.  On the Louisiana coast the
mean January temperature is 52 degrees Fahrenheit (11 deg C).  Mean
August temperature is 82 degrees Fahrenheit (28 deg C).  Rainfall is
highest in July and lowest in October, with an annual range of 58 to 66
inches (1,470-1,670 mm).  The growing season is 317 days [2].
Hurricanes occur from June through November, with most occurring between
August and October [13].


SOILS : 
Soils in this type are mostly Histosols or Mollisols [4].  Soil textures
are silts, clays, and silt clays.  The silts result from recent alluvial
and marine deposits.  Organic layer depths range from a few inches to 20
feet (6.3 m).  Most sites are waterlogged [2].


VEGETATION : 
The southern cordgrass prairie is composed mostly of smooth cordgrass
(Spartina alterniflora), which occurs in high salinity areas.  Smooth
cordgrass occurs with perennial glasswort (Sarcocornia perennis) in low
tidal marshes where saltwater inundation is greatest [15].  In other
saline areas some components of the southern cordgrass prairie include
saltgrass (Distichlis spicata), marshhay cordgrass (Spartina patens),
and black rush (J. roemerianus).  In less saline and more brackish
conditions, components include big cordgrass (Spartina cynosuroides),
switchgrass (P. virgatum), and Olney threesquare (Scirpus americanus)
[11].  Species that occur in freshwater or slightly brackish sites
include bog rush (Juncus effusus), Jamaica sawgrass (Mariscus
jamicensis), maidencane (Panicum hemitomon), panicum (P. repens), common
reed (Phragmites australis), arrowhead (Sagittaria spp.), California
bulrush (Scirpus californicus), softstem bulrush (S. validus), gulf
cordgrass (Spartina spartinae), southern cattail (Typhus domingensis),
and great cutgrass (Zizaniopsis miliacea) [6].  The southern cordgrass
type has few if any forbs and shrubs [4].


WILDLIFE : 
The southern cordgrass prairie is home to many threatened and endangered
species.  Threatened species include the loggerhead turtle.  Endangered
species include the leatherback turtle, green sea turtle, hawksbill
turtle, Kemp's ridley sea turtle, American alligator, whooping crane,
Eskimo curlew, eastern brown pelican, Attwater's prairie chicken, bald
eagle, Arctic peregrine falcon, Bachman's warbler, red-cockaded
woodpecker, and the Texas red wolf [4,13].  Nonendangered species
include raccoon, muskrat, white-tailed deer, many waterfowl species,
passerine birds, osprey, hawks, and falcons [4].


ECOLOGICAL RELATIONSHIPS : 
Both water level and salinity influence species composition of smooth
cordgrass stands [12].  These stands can tolerate saltwater inundation
for as long as 20 hours per day. Cordgrass is dominant in the saline
coastal marshes of Texas and Louisiana [2], and where salinity is
between 3 and 5 percent and the water table averages 4 inches (10 cm)
above ground [1]. In Louisiana smooth cordgrass often occurs in pure
stands or with saltgrass and black rush associates.  It also occurs as
an understory to American mangrove (Rhizophora mangle), which sometimes
displaces it [12].

Where saline conditions develop, smooth cordgrass invades shallow water
and remains dominant unless these areas become aggraded by inorganic
sediments.  It invades freshwater marshes when these marshes are cut off
from their freshwater sources and slowly become brackish.  Smooth
cordgrass also invades brackish ditches and ponds with silt or clay
substrates.  As organic matter builds up, it is replaced by marshhay
cordgrass, saltgrass, and black rush [12]. Under droughty or dry
conditions, saltgrass increases.  As salinity decreases smooth cordgrass
is first succeeded by Olney threesquare, which is followed by marshhay,
cordgrass, common reed, and finally giant cordgrass.  Black rush can
increase following disturbance by fire or grazing in smooth cordgrass
stands [1].  Fire may prevent succession to trees or woody vegetation in
coastal marshes dominated by grasses, particularly in Florida mangrove
ecosystems.  Frost, however, may be more effective at controlling
mangrove [14].

Related categories for Kuchler Type: Southern cordgrass prairie