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Full-Text Articles in Physical Sciences and Mathematics
Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak
Differential Responses Of Soil Greenhouse Gas Production And Denitrification To Salinity Alterations Along A Wetland Salinity Gradient, Natalie Ceresnak
LSU Master's Theses
Coastal wetlands provide several valuable services, such as carbon (C) storage and nitrogen (N) removal. Although wetlands serve as net C sinks, wetland soils release greenhouse gases (GHGs) including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Wetlands can buffer the influx of nitrate (NO3-) by transforming it into gaseous N (N2O, N2) through denitrification microbial pathway. Salinity is a regulator of soil biogeochemistry and long- (e.g. saltwater intrusion) and short-term (e.g. storm surges, river diversions) exposures may affect soil GHG production and denitrification. In this study, soil GHG production and denitrification enzyme activity (DEA) rates were examined over …
Effect Of The Bp Deepwater Horizon Oil Spill On Critical Marsh Soil Microbial Functions, Jason Paul Pietroski
Effect Of The Bp Deepwater Horizon Oil Spill On Critical Marsh Soil Microbial Functions, Jason Paul Pietroski
LSU Master's Theses
On April 20, 2010, the BP Deepwater Horizon (DWH) offshore oil platform exploded releasing ~ 795 million L of southern Louisiana (LA) light sweet crude oil into the Gulf of Mexico. Approximately 7.9 million liters of dispersant, Corexit EC9500A, were applied for remediation. The effect of BP DWH crude oil and Corexit EC9500A on two marsh soil microbial processes, (mineralizable nitrogen and denitrification), were examined in the laboratory. Surface soil samples were collected from an unimpacted salt marsh site proximal to areas that suffered light to heavily oiling in Barataria Bay, LA. Additions of oil were at a ratio of …
The Effects Of Carbon On Nitrogen Transformations In Restored Wetland And Wastewater Soils, Jared M. Theriot
The Effects Of Carbon On Nitrogen Transformations In Restored Wetland And Wastewater Soils, Jared M. Theriot
LSU Master's Theses
Since the industrialization of the Haber-Bosch process in the 1940’s, anthropogenic activity has nearly doubled the Earth’s nitrogen fixation. Furthermore, nitrate has become the number one groundwater contaminant in the United States and has harmful effects such as eutrophication, algal blooms, and pollution of drinking water. Soils from two sites influenced by high nitrate loading were examined to determine their biogeochemical integrity. First, the Loosahatchie Bar, located northwest of Memphis, Tennessee, is influenced by excess surface water nitrate loading by the Mississippi River. The Loosahatchie Bar is a newly restored wetland that now has similar hydrologic influence to an upstream …
Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren
Fate Of Mississippi River Diverted Nitrate On Vegetated And Non-Vegetated Coastal Marshes Of Breton Sound Estuary, Christine M. Vanzomeren
LSU Master's Theses
The Caernarvon Diversion meters Mississippi River water into coastal marshes of Breton Sound. Elevated levels of nitrogen in river water have sparked concerns that nutrient loading may affect marsh resilience and belowground biomass, as evidence from several marsh fertilization studies. These concerns resulted from observation that fresh and brackish Breton Sound marshes suffered extensive damage from Hurricane Katrina. The goal of this study is to determine the fate of nitrate (the dominant inorganic nitrogen form in the Mississippi River) in Breton Sound Estuary marshes. We hypothesized that most nitrate would be removed by denitrification and that nitrate loading would not …
The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks
The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks
LSU Master's Theses
Wetlands in the coastal zone are slowly becoming more saline under rising sea level over the long-term. However, there are a number of events in the coastal environment which lead to quick and temporary changes in the salinity of coastal marshes. Seawater driven inland from storm surge can significantly increase salinity in oligohaline wetlands over the short-term (weeks). Recent large-scale efforts to restore coastal wetlands in Louisiana have utilized Mississippi River surface water diversions to re-introduce freshwater into coastal marshes, decreasing the salinity of coastal marshes. We examined the effect of salinity changes on two important nitrogen cycling processes, potential …
Applying The Isotope Pairing Technique To Evaluate How Water Temperature And Habitat Type Influence Denitrification Estimates In Breton Sound, Louisiana, Peter L. Lenaker
Applying The Isotope Pairing Technique To Evaluate How Water Temperature And Habitat Type Influence Denitrification Estimates In Breton Sound, Louisiana, Peter L. Lenaker
LSU Master's Theses
The upper Breton Sound estuary was hydrologically reconnected to the Mississippi River via the Caernarvon freshwater diversion structure in 1991. The Caernarvon structure can provide controlled freshwater pulses to the upper Breton Sound estuarine ecosystem, replicating historic freshwater pulsed events, although the original authorization was to control salinity isohalines at specific locations in the estuary. However, unlike historic freshwater pulsed events prior to the construction of levees, the current freshwater pulse contains an unprecedented amount of inorganic nitrogen, predominately as nitrate (annual average 71.4 µM NO3-). Denitrification is a microbial process, which can potentially remove excess nitrate entering coastal Louisiana …