Louisiana coastal marshes

Farlow, J.E. 1976. Dimilin [l-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)-urea] on the Aquatic Fauna of a Louisiana Coastal Marsh. Ph.D. thesis, Louisiana State Univ. Agricul. Mech. Coll., Baton Rouge, LA. 144 pp. 

Foote, A. L., and Reynolds, K.A. (1997) Salt meadow cordgrass (Spartina patens) decomposition and its importance in Louisiana coastal marshes. Estuaries 20, 579-588. 

DeLaune R. D., Devai I., and Lindau C. W. (2002) Flux of reduced sulfur gases along a salinity gradient in Louisiana coastal marshes. Estuar. Coast. Shelf Sci. 54, 1003-1011. 

In Louisiana coastal marsh soils, inorganic sulfur constitutes 13-30% of the total sulfur pool, with HCl-soluble sulfur representing 78-86% of the inorganic sulfur fraction in freshwater, brackish, and salt marsh (Pezeshki et al., 1991 Krairapanond et al., 1992). AVS accounted for <1% of the total sulfur pool. Pyrite sulfur and elemental sulfur together accounts for 8-33% of the inorganic sulfur pool (Krairapanond et al., 1992). 

FIGURE 14.19 Relationship between hulk density and soil organic carbon content in Louisiana coastal marsh soil. (Data from Hatton et ah, 1983.)... 

The relative rates of vertical marsh accretion and submergence determine the long-term stability of Louisiana coastal marshes. Coastal marshes are highly susceptible to submergence associated with a rise in relative sea level (Penland and Ramsey, 1989). Louisiana coastal marshes are undergoing rapid subsidence and currently experiencing rapid increases in the water level. Research conducted over the past quarter century in coastal Louisiana has shown that marsh accretion at many... 

FIGURE 18.5 Schematic of how the increase in coastal submergence impacts Louisiana coastal marsh stability. 

The amounts and profile distribution of various sulfur forms in Louisiana coastal marshes are important in understanding sulfur cycling as related to the origin and type of tidal wetland marshes. Sulfur forms and distribution were determined in P. hemitomon freshwater marsh, a S. patens brackish marsh, and a S. alterniflora salt marsh along a salinity gradient in Barataria Basin, Louisiana. Soil samples were fractionated into acid volatile sulfur (AVS), elemental sulfur, HCl-soluble sulfur, pyrite sulfur, ester sulfate sulfur, carbon-bonded sulfur, and total sulfur (see Chapter 11 for details). 

What is the primary source of inorganic nitrogen for plant growth in Louisiana coastal marsh ... 

Explain the importance of sediment as a source of nitrogen to Louisiana coastal marsh. 

Chabreck R. H. and Linscombe G. (1978) Vegetative Type Map of the Louisiana Coastal Marshes 1978. Louisiana Department of Wildlife and Fisheries, New Orleans. 

Guntenspergen G. R., Cahoon D. R., Grace J., Steyer G. D., Fournet S., Towson M. A. and Foote A. L. (1995) Disturbance and recovery of the Louisiana coastal marsh landscape from the impacts of Hurricane Andrew. J. Coastal Res. 21, 324-339. 

Reed D. J. and Rozas L. P. (1995) An evaluation of the potential for infilling existing pipeline canals in Louisiana coastal marshes. Wetlands 15, 149-158. 

Geopressured Zones. A test well in a geopressure zone was drilled some years ago in Tigre Lagoon in the coastal marshes of southern Louisiana Known as Edna Delcambre 1, this well produced at a rate of np to 10,000 barrels of water per day from a sandstone aquifer some 12,600 feet (3840 meters) below the surface. Pressure at that depth is nearly 11,000 pounds per square inch (748 atmospheres) and the temperature is 116°C. Quite an elaborate manifold system is requited to collect the gas. The water is disposed by forcing it by... 

Lake Pontchartraln receives drainage from an area of approximately 5,000 square miles located mostly to its north. Several rivers drain the Louisiana coastal plain terraces while two other rivers drain the former Mississippi River floodplain southwest and west of the lake. From the south. Lake Pontchartraln receives extensive wetland (marsh and swamp) drainage. The greater New Orleans area, which includes Jefferson and Orleans Parishes, is now leveed off from the lake. However, this metropolitan area, home for over a million people, is drained by pumping from an extensive network of man-made canals into Lake Pontchartraln. 

Coastal Wetlands Mississippi River Deltaic Plain Coastal Marshes, Louisiana... 

The major processes involved in marsh stability dynamics within Louisiana coastal wetlands are... 

FIGURE 18.7 Relationship between soil bulk density and aboveground biomass of the Louisiana saline coastal marsh supporting the species Spartina alterniflora. (Adapted from DeLaune et ah, 1990b.)... 

A series of diversion projects have been implemented to reintroduce freshwater and sediment from the Mississippi River into Louisiana coastal wetlands (Figure 18.9). A recent study examined the impact of Mississippi River freshwater diversion on enhancing vertical marsh accretion (mineral and organic matter accumulation) in Breton Sound estuary, a coastal wetland experiencing marsh deterioration as a result of subsidence and saltwater intrusion (DeLaune et al., 2003). The Caernarvon diversion has positively impacted marsh accretion in Brenton Sound estuary helping to slow or reverse wetland loss. Several hundred hectares of new marsh have been created by the introduction of Mississippi River water into the system (Villarrubia, 1998). 

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