Physical Sciences and Mathematics Commons^™

Effects Of Marsh Management In Coastal Marsh Impoundments On Marsh Vertical Accretion In The Face Of Sea Level Rise., Scott P. Graham

LSU Master's Theses

Many coastal marshes are managed for wildlife through the use of levees and water control structures. Management techniques such as water manipulation, herbicide application, and controlled burns are used to set back succession and facilitate recruitment of annual plant species, which are highly sought after by many wildlife. These marsh impoundments alter or prevent natural tidal exchange, which might alter or prevent sediment and nutrient inputs to the marsh. Although these management techniques are effective in managing for wildlife, there are few studies comparing vertical accretion between managed and unmanaged marshes. Vertical accretion is important because it allows coastal wetlands …

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …

From The River To The Gulf: An Investigation Of Biogeochemical Cycling In Wetland Soils And Coastal Shelf Sediments, Katie Bowes

LSU Master's Theses

Louisiana is home to 40% of the coastal wetlands in the lower 48 states, yet accounts for 80% of the coastal wetland loss in this region. This loss is attributed to decreased sediment supply, levee alteration, sea level rise, channelization, and subsidence. The levee system in Louisiana disconnected coastal wetlands from the main stem of the Mississippi River (MSR), reducing the amount of land-building sediment that reaches coastal wetlands. This disconnection also allows a greater percentage of river discharge, including agricultural contaminants and runoff, to flow into the northern Gulf of Mexico (NGOM).

The 2012 Coastal Master Plan proposed eight …

Living On The Edge: An Assessment Of The Habitat Use Of Waterbirds In Estuarine Wetlands Of Barataria Basin, La, Brett Ashley Patton

LSU Master's Theses

The wetlands of Louisiana are losing area at the rapid rate of 42.9 km2 yr-1 and the trend is expected to continue. This combined with expected sea-level rise will likely cause large shifts in vegetation and salinity regimes that will affect the wildlife species reliant on these ecosystems. Waterbirds serve as indicator species of ecosystem health in estuarine wetland habitats; therefore, these species are often the targets of wetland management goals in Louisiana. However, many proposed wetland restoration projects are focused primarily on social impacts with only a few specific waterbird species designated for management. The majority of these waterbird …

Influences On The Successful Implementation Of The Convention On Wetlands Of International Importance (Ramsar) Among Member Countries, Aziza Saud Al Adhoobi

LSU Master's Theses

Wetlands are very dynamic ecosystems and are featured all over the world’s landscape. Recent studies suggested that wetlands are in continuous decline, both and quantity and quality and between 64-71% is the estimated global wetland loss in the 20th century (Davidson 2014; Gardner et al., 2015). Therefore, as wetland loss increases around the world, more effort to protect and restore wetland habitat, values, and services become crucial. For this reason, the Ramsar Convention was established four decades ago to highlight the severity of wetland loss and to produce guidelines that aim to guide Contracting Parties toward sustainable and efficient management …

Analyzing Site Suitability For Baldcypress (Taxodium Distichum) Regeneration Along A Hydrologic Gradient In South Louisiana Swamps, Marcus Rutherford

LSU Master's Theses

The future of Louisiana’s coastal cypress-tupelo forests is threatened by prolonged or permanent flooding during the growing season. Permanent inundation prevents baldcypress seedlings from becoming established. The upper limit of submergence with respect to adequate planted baldcypress seedling performance has not been effectively tested under actual field conditions. Similarly, an effective method for determining a site’s regeneration potential based on present vegetation attributes has not been developed. To test first-year performance of planted baldcypress seedlings under varying levels of submergence, I planted 900 of both 1-0 and 2-0 age-class bare-root seedlings across 12 different sites covering a range of hydrologic …

Anthropogenic Impacts On Soil Microbial Processes In Coastal Wetlands: Nutrient Loading And Rising Co2 Levels, Havalend Ellen Steinmuller

LSU Master's Theses

Atmospheric carbon dioxide (CO2) levels and global eutrophication are anthropogenic stressors impacting the environment of specific interest in wetland systems. Wetlands occupy a critical interface between terrestrial and aquatic environments. Fertilizer use for agriculture and treated wastewater disposal has increased nutrient loading to wetlands. Conflicting results on impacts of nitrogen loading to coastal wetland soils have been reported, though most studies have investigated short-term impacts of nutrient loading, not long-term integrated impacts. I investigated an 11-year period of nutrient loading on soils in an oligohaline coastal wetland. Nitrogen treatments of 0, 50, 200, and 1200 kg ha-1 yr-1 were paired …

The Adoption Of State Wetland Policies: How Do Wetlands Fit Within The Theoretical Framework Of Environmental Policy Determinants?, Rachel Bogart Krech

LSU Master's Theses

Wetlands are an extremely important natural resource in the United States. They offer storm surge protection, sediment stabilization, groundwater recharging, carbon sequestration, and habitat for many species. Despite their values, wetlands have a long history of being misunderstood. It was not until the mid-1970s that scientific understanding helped transform policy from that of rapid conversion to that of conservation. By this time, the lower 48 states had already lost 53 percent of its total wetlands. The nature of wetlands and federal limitations make the management of this natural resource a primarily state-based responsibility. However, the way that states construct their …

Some Effects Of Nutrient And Flooding Stress Manipulation On Coastal Louisiana Wetland Vegetation, James Stephen Ialeggio

LSU Master's Theses

Freshwater diversions are a relatively recently utilized tool in wetland loss mitigation that stimulate an organic accretion response in marsh vegetation, which is based in root production and thus belowground biomass. The effectiveness of freshwater diversions in slowing marsh loss probably varies across a gradient of the factors they supply: decreased salinity, increased nutrient concentrations, and increased inundation. Flooding stress is commonly thought to be the overriding factor limiting wetland vegetation growth, however its influence may vary across salinity and nutrients. Therefore, plugs of Spartina patens were planted in four “marsh organs” consisting each of 36 sediment-filled PVC pipes of …

Dendrochronological Analysis Of Productivity And Hydrology In Two Louisiana Swamps, John Blake Amos

LSU Master's Theses

Modified river flows and land subsidence have subjected many coastal swamp forests in the delta of the Mississippi River to greatly altered flooding, sediment, and nutrient regimes. These areas have become inundated to greater depth, duration, and frequency and either are connected to the river and receive drastically increased sediment and nutrients (riverine swamps) or have become disconnected from riverine flooding (stagnant swamps) and receive little or no sediment and nutrient input. To better understand how these changes are affecting ecosystems, dendrochronological techniques for baldcypress (Taxodium distichum L. Rich.) were used at three sites in each of two contrasting swamps …

Designation Of The Southwest National Wildlife Refuge Complex As Wetlands Of International Importance Under Ramsar, Convention On Wetlands Of International Importance, Mitchell Ward Coffman

LSU Master's Theses

The historical loss and continued threat of loss of Louisiana wetlands is a major environmental concern for the United States and the world. In 1971, the Ramsar Convention, an international environmental treaty was ratified to specifically address conservation planning and land use management issues involving wetlands of the world. Ramsar provides an international designation award called, the Wetlands of International Importance List, which formally acknowledges globally important wetland landscapes. Ramsar outlines specific criterion nominated wetland sites must possess for consideration of this listing.

The Southwest Louisiana National Wildlife Refuge Complex is an excellent candidate for nomination to the Ramsar Convention …