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Environmental Sciences

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Louisiana State University

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2020

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Articles 1 - 9 of 9

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Salt Marsh Elevation Limit Determined After Subsidence From Hydrologic Change And Hydrocarbon Extraction, R. Eugene Turner, Yu Mo Dec 2020

Salt Marsh Elevation Limit Determined After Subsidence From Hydrologic Change And Hydrocarbon Extraction, R. Eugene Turner, Yu Mo

Faculty Publications

Levee construction aboveground and hydrocarbon removal from belowground in coastal wetlands can create hydrologic changes that increase plant stress through flooding. But the significance of the subsidence they cause individually or in combination is contested. This study untangled them to demonstrate elevational limits of salt marshes by studying dredged and natural waterways in two salt marshes in Louisiana, USA. The areas had a homogenous plant cover before drilling for oil and gas extraction peaked in the 1960s, and now are a mixed network of natural waterways and dredged canals used to drill wells with an average drill date of 1965.8 …


Unraveling The Gordian Knot: Eight Testable Hypotheses On The Effects Of Nutrient Enrichment On Tidal Wetland Sustainability, Thomas J. Mozdzer, Elizabeth Burke Watson, William H. Orem, Christopher M. Swarzenski, R. Eugene Turner Nov 2020

Unraveling The Gordian Knot: Eight Testable Hypotheses On The Effects Of Nutrient Enrichment On Tidal Wetland Sustainability, Thomas J. Mozdzer, Elizabeth Burke Watson, William H. Orem, Christopher M. Swarzenski, R. Eugene Turner

Faculty Publications

The position of tidal wetlands at the land-sea interface makes them especially vulnerable to the effects of nutrient discharges and sea level rise (SLR). Experimental studies of coastal wetland nutrient additions report conflicting results among and within habitats, highlighting the importance of site-specific factors, and how spatial and temporal scaling modulates responses. This suite of influences as SIR accelerates creates a "Gordian Knot" that may compromise coastal habitat integrity. We present eight testable hypotheses here to loosen this knot by identifying critical modulators about nutrient form, soil type and porosity, physiochemical gradients, and eco-evolutionary responses that may control the impacts …


Potential Link Between Compromised Air Quality And Transmission Of The Novel Corona Virus (Sars-Cov-2) In Affected Areas, M. G. Manoj, M. K. Satheesh Kumar, K. T. Valsaraj, C. Sivan, Soumya K. Vijayan Nov 2020

Potential Link Between Compromised Air Quality And Transmission Of The Novel Corona Virus (Sars-Cov-2) In Affected Areas, M. G. Manoj, M. K. Satheesh Kumar, K. T. Valsaraj, C. Sivan, Soumya K. Vijayan

Faculty Publications

The emergence of a novel human corona virus disease (COVID-19) has been declared as a pandemic by the World Health Organization. One of the mechanisms of airborne transmission of the severe acute respiratory syndrome corona virus (SARS-CoV-2) amid humans is through direct ejection of droplets via sneezing, coughing and vocalizing. Nevertheless, there are ample evidences of the persistence of infectious viruses on inanimate surfaces for several hours to a few days. Through a critical review of the current literature and a preliminary analysis of the link between SARS-CoV-2 transmission and air pollution in the affected regions, we offer a perspective …


The Role Of Sediment-Induced Light Attenuation On Primary Production During Hurricane Gustav (2008), Zhengchen Zang, Z. George Xue, Kehui Xu, Samuel J. Bentley, Qin Chen, Eurico J. D'Sa, Le Zhang, Yanda Ou Oct 2020

The Role Of Sediment-Induced Light Attenuation On Primary Production During Hurricane Gustav (2008), Zhengchen Zang, Z. George Xue, Kehui Xu, Samuel J. Bentley, Qin Chen, Eurico J. D'Sa, Le Zhang, Yanda Ou

Faculty Publications

We introduced a sediment-induced light attenuation algorithm into a biogeochemical model of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system. A fully coupled ocean-atmospheric-sediment-biogeochemical simulation was carried out to assess the impact of sediment-induced light attenuation on primary production in the northern Gulf of Mexico during the passage of Hurricane Gustav in 2008. When compared with model results without sediment-induced light attenuation, our new model showed a better agreement with satellite data on both the magnitude of nearshore chlorophyll concentration and the spatial distribution of offshore bloom. When Hurricane Gustav approached, resuspended sediment shifted the inner shelf ecosystem from a nutrient-limited …


Ideas And Perspectives: The Same Carbon Behaves Like Different Elements - An Insight Into Position-Specific Isotope Distributions, Yuyang He, Xiaobin Cao, Huiming Bao Oct 2020

Ideas And Perspectives: The Same Carbon Behaves Like Different Elements - An Insight Into Position-Specific Isotope Distributions, Yuyang He, Xiaobin Cao, Huiming Bao

Faculty Publications

It is expected that information on the source, reaction pathway, and reaction kinetics of an organic compound can be obtained from its position-specific isotope compositions or intramolecular isotope distribution (Intra-ID). To retrieve the information, we could use its predicted equilibrium Intra-ID as a reference for understanding the observed Intra-IDs. Historically, observed, apparently close-to-equilibrium carbon Intra-ID has prompted an open debate on the nature of biosystems and specifically the pervasiveness of reversible biochemical reactions. Much of the debate remains unresolved, and the discussion has not clearly distinguished between two states of equilibrium: (1) the equilibrium among the corresponding bond-breaking and bond-forming …


Environmentally Clean Access To Antarctic Subglacial Aquatic Environments, Alexander B. Michaud, Trista (Vick-Majors, Amanda M. Achberger, Mark L. Skidmore, Brent C. Christner, Martyn Tranter, John C. Priscu Oct 2020

Environmentally Clean Access To Antarctic Subglacial Aquatic Environments, Alexander B. Michaud, Trista (Vick-Majors, Amanda M. Achberger, Mark L. Skidmore, Brent C. Christner, Martyn Tranter, John C. Priscu

Faculty Publications

Subglacial Antarctic aquatic environments are important targets for scientific exploration due to the unique ecosystems they support and their sediments containing palaeoenvironmental records. Directly accessing these environments while preventing forward contamination and demonstrating that it has not been introduced is logistically challenging. The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project designed, tested and implemented a microbiologically and chemically clean method of hot-water drilling that was subsequently used to access subglacial aquatic environments. We report microbiological and biogeochemical data collected from the drilling system and underlying water columns during sub-ice explorations beneath the McMurdo and Ross ice shelves and …


The Dynamic Trophic Niche Of An Island Bird Of Prey, Ulises Balza, Nicolas A. Lois, Michael J. Polito, Klemens Puetz, Amira Saalom, Andrea Raya Rey Oct 2020

The Dynamic Trophic Niche Of An Island Bird Of Prey, Ulises Balza, Nicolas A. Lois, Michael J. Polito, Klemens Puetz, Amira Saalom, Andrea Raya Rey

Faculty Publications

Optimal foraging theory predicts an inverse relationship between the availability of preferred prey and niche width in animals. Moreover, when individuals within a population have identical prey preferences and preferred prey is scarce, a nested pattern of trophic niche is expected if opportunistic and selective individuals can be identified. Here, we examined intraspecific variation in the trophic niche of a resident population of striated caracara (Phalcoboenus australis) on Isla de los Estados (Staten Island), Argentina, using pellet and stable isotope analyses. While this raptor specializes on seabird prey, we assessed this population's potential to forage on terrestrial prey, especially invasive …


Potential Pollen Evidence For The 1933 M 7.5 Diexi Earthquake And Implications For Post-Seismic Landscape Recovery, Hongyan Xu, Hanchao Jiang, Kam-Biu Liu, Ning Zhong Sep 2020

Potential Pollen Evidence For The 1933 M 7.5 Diexi Earthquake And Implications For Post-Seismic Landscape Recovery, Hongyan Xu, Hanchao Jiang, Kam-Biu Liu, Ning Zhong

Faculty Publications

The relationships between strong earthquakes, landslides, and vegetation destruction and the process of post-seismic recovery in tectonically active alpine valley areas have not been adequately documented. Here we show detailed pollen study results from a swamp located near the epicenter of the 1933 M 7.5 Diexi earthquake in eastern Qinghai-Tibetan Plateau (QTP) to reveal the impact of earthquake on vegetation, and the post-seismic recovery process. Based on(210)Pb-Cs-137 age model, the seismic event layer is well constrained. The earthquake event corresponds stratigraphically to a zone with the lowest pollen concentrations, the lowest pollen diversity, and a high frequency of non-arboreal pollen. …


Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim Aug 2020

Traffic Impacts Of The Covid-19 Pandemic: Statewide Analysis Of Social Separation And Activity Restriction, Scott Parr, Brian Wolshon, John Renne, Pamela Murray-Tuite, Karl Kim

Faculty Publications

The COVID-19 pandemic resulted in significant social and economic impacts throughout the world. In addition to the health consequences, the impacts on travel behavior have also been sudden and wide ranging. This study describes the drastic changes in human behavior using the analysis of highway volume data as a representation of personal activity and interaction. Same-day traffic volumes for 2019 and 2020 across Florida were analyzed to identify spatial and temporal changes in behavior resulting from the disease or fear of it and statewide directives to limit person-to-person interaction. Compared to similar days in 2019, overall statewide traffic volume dropped …