Ecology and Evolutionary Biology Commons^™

Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen

LSU Doctoral Dissertations

The Mississippi River Delta is threatened by a growing pressure to support large human populations in the United States both with food production, navigation systems, and urban development in the Mississippi River Basin. Nitrate-nitrogen load in the Mississippi River, up to 100 Tg N yr^-1 from agricultural and urban runoff, leads to phytoplankton blooms and hypoxia across the Louisiana continental shelf, creating dead zones of low dissolved oxygen threatening a significant commercial fishery. Along the coast and river corridors, floodplain ecosystems have the capacity to retain and remove nitrate. This dissertation explores the role of productive, actively growing coastal …

An Ecopath With Ecosim Analysis On Offshore Petroleum Platform Influences On Gulf Of Mexico Red Snapper, Valentin Gomez

LSU Master's Theses

Offshore oil and gas platforms have had a significant presence in the Gulf of Mexico since the 1950s. An important secondary function of these structures is that they provide artificial habitat to fisheries, most notably Red snapper. Policy changes intended to reduce the risk associated with aging infrastructure have reduced the number of standing platforms from 4044 to 1867 from 2001 to 2018. The effect this loss of habitat has on Red snapper was tested by creating three scenarios of platform changes and modeling the perturbation from 2005 to 2050. The simulation was accomplished using the ecological model Ecopath with …

Taxonomy And Systematics Of The New Zealand Pselaphini (Coleoptera: Staphylinidae: Pselaphinae), Brittany Elin Owens

LSU Doctoral Dissertations

The New Zealand (NZ) Pselaphini was revised at the species level, a phylogenetic analysis was performed using morphological data, and first steps were taken towards the construction of a molecular analysis of the tribe. Eight new genera and 33 new species were discovered from specimens collected from the NZ mainland, offshore islands, Chatham Islands and the Subantarctic Islands. Of the 13 species originally described in the genus Pselaphus by Thomas Broun during the late 19^th and early 20^th centuries, all were either reassigned to the genera Pselaphaulax and Pselaphogenius, or were placed into new genera. Three names …

Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths

LSU Doctoral Dissertations

Our rapidly changing climate is putting many species at risk of extinction and there is an urgent need to understand how species will respond to these changes. In this dissertation, I evaluate how three species of marine invertebrates (corals, oysters, and copepods) respond to stressful conditions in their current environments and how plasticity and evolutionary adaptation could alter their response to future climate change stressors. I first employed a space for time study to elucidate population differences in the response of cold-water corals, Balanophyllia elegans, to future ocean acidification. I found evidence that upwelling history (natural low pH exposure) influences …

Effects Of Freshwater Inflow On Nekton Assemblages And Blue Crab Populations In Southeastern Louisiana, Caleb Benjamin Taylor

LSU Master's Theses

Estuaries along the northern Gulf of Mexico represent some of the most productive ecosystems in the world, providing vital habitat for many recreationally and commercially valuable species, including the blue crab, Callinectes sapidus. The mixing of fresh river and saline ocean water in coastal estuaries contribute to this productivity. Dominated by large river influences and consisting of multiple estuaries, Louisiana contributes the largest commercial fishery in the Gulf of Mexico, and remains, on average, the largest supplier of blue crabs in the nation. However, across southeast Louisiana, freshwater flow is largely dependent on Mississippi River discharge, which is highly …

Role Of Coastal Environmental Conditions During Austral Winter On Plankton Community Dynamics And The Occurrence Of Pseudo-Nitzschia Spp. And Domoic Acid In Inhambane Province, Mozambique, Holly Kelchner

LSU Master's Theses

Harmful algal blooms (HABs) are increasing globally in frequency, persistence, and geographic extent. HABs pose a threat to economic stability, and ecosystem and human health. To date no incidences of marine toxins produced by phytoplankton have been recorded in Mozambique, which may be due to the absence of a monitoring program and general awareness of the potential threat. This study is the first documentation of the occurrence of a neurotoxin, domoic acid (DA), produced by the diatom genus Pseudo-nitzschia spp. along the east coast of Africa. The coast of Inhambane Province is a biodiversity hotspot where year-round Rhincodon typus (whale …

Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan

LSU Doctoral Dissertations

The impacts of sea-level rise and hydrologic manipulation are threatening the stability of coastal marshes throughout the world, thereby increasing the potential for re-mineralization of soil organic matter (SOM) in these systems. Such threats have prompted marsh restoration efforts, particularly in coastal Louisiana, yet it is unclear how the slowly decomposing (refractory) and quickly decomposing (labile) fractions of SOM may be differentially affected by different approaches to marsh restoration. Additionally, otherwise labile compounds may accumulate in the soil via a range of protective mechanisms, including rapid burial and association with organic compounds that are thought to enhance soil aggregation, such …

Evaluation Of Space Use And Movement By Wild Turkey (Meleagris Gallopavo) During Extreme Climatic Disturbances And Annual Phenological States, David J. Moscicki

LSU Master's Theses

Space use is driven by both intrinsic and extrinsic factors across space and time. Meaning a species demography and habitat requirements may vary across landscapes. Recent studies on wild turkeys (Meleagris gallopavo spp., hereafter turkey) have shown both direct and indirect demographic impacts of climatically driven events on turkey populations. Similarly, there is an abundance of information documenting turkey demographic parameters and space use, but few studies have addressed breeding phenology in great detail. We evaluated the impact on space use and movement patterns of Eastern wild turkeys (M. g. silvestris; n = 20) and Rio Grande wild …

Habitat Associations And Reproduction Of Fishes On The Northwestern Gulf Of Mexico Shelf Edge, Elizabeth Marie Keller

LSU Doctoral Dissertations

Several of the northwestern Gulf of Mexico (GOM) shelf-edge banks provide critical hard bottom habitat for coral and fish communities, supporting a wide diversity of ecologically and economically important species. These sites may be fish aggregation and spawning sites and provide important habitat for fish growth and reproduction. Already designated as habitat areas of particular concern, many of these banks are also under consideration for inclusion in the expansion of the Flower Garden Banks National Marine Sanctuary. This project aimed to gain a more comprehensive understanding of the communities and fish species on shelf-edge banks by way of gonad histology, …

Reproductive Parameters And Female Breeding Season Survival Of Rio Grande Wild Turkeys In South Central Texas, Jacob White

LSU Master's Theses

Historically, Rio Grande wild turkeys in south central Texas have been at lower densities than other portions of the state. Within the Oak-Prairie Wildlife District of Texas, Rio Grande wild turkey regulatory restrictions are different for counties in the eastern and western portions of the ecoregion. Due to perceived increases in turkey density in the eastern portion of the ecoregion (hereafter 1-bird zone), Texas Parks and Wildlife Department (TPWD) considered increasing the bag limit to match counties in the western portion of the district (hereafter 4-bird zone) in order to increase hunting opportunities. However, if regulatory changes are to be …

Ornithological Expeditions To Sarawak, Malaysian Borneo, 2007-2017, Frederick H. Sheldon, Haw Chuan Lim, Phred M. Benham, Matthew L. Brady, Clare E. Brown, Ryan C. Burner, Vivien L. Chua, John C. Mittermeier, Subir B. Shakya, Paul Van Els, Mustafa Abdul Rahman, Dency F. Gawin, Zahirunisa Abdul Rahim, Luisa Duya Setia, Robert Moyle

Occasional Papers of the Museum of Natural Science, Louisiana State University

Louisiana State University, the University of Kansas, and the Universiti Malaysia Sarawak undertook collaborative research on the evolution and ecology of Bornean birds starting in 2005. This collaboration included a series of expeditions from 2007–2017 to collect and study birds at >30 sites in Sarawak, Malaysian Borneo. Here we provide information on the study-sites and summarize the main discoveries resulting from the collaboration.

Quantifying Impacts Of Climate Change On Species Interactions While Fostering Undergraduate Research Experiences Using The Monarch (Danaus Plexippus)- Milkweed (Asclepias Sp.) System, Matthew J. Faldyn

LSU Doctoral Dissertations

Species interactions, specifically plant-insect interactions, are ubiquitous worldwide. Climate change will alter species interactions by affecting abiotic conditions, affecting species phenologies, interaction strengths, and physiological development. However, climate change impacts are often studied using individual species, with limited consideration quantifying the direct and indirect impacts of climate change species interactions. Using lab, field, and greenhouse experiments, I investigated how climate change will directly and indirectly affect species interactions while also fostering undergraduate research experiences using the monarch butterfly (Danaus plexippus)- milkweed (Asclepias sp.) system.

In North America, a widely planted, invasive milkweed species, Asclepias curassavica, negatively …

Factors Affecting Nest Success Of Colonial Nesting Waterbirds In Southwest Louisiana, Karis A. Ritenour

LSU Master's Theses

As the coastline of Louisiana shifts with global climate change, subsidence, and accelerated sea level rise, important breeding islands for colonial nesting waterbirds are disappearing. In many recent studies flooding has been a leading cause of nest failure for a variety of species, especially those that nest on the ground. I examined the nest success of four species of colonial nesting waterbirds with various nesting strategies on Rabbit Island in southwestern Louisiana during 2017 and2018 by determining nest and fledging success. I monitored 855 nests, including 457 Brown Pelicans nests with an estimated hatch probability of 70%, 270 Forster’s Terns …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Spatiotemporal Impact Of Snow On Underwater Photosynthetically Active Radiation In Taylor Valley, East Antarctica, Madeline E. Myers

LSU Master's Theses

The role of snow on underwater photosynthetically active radiation (UW PAR) in the McMurdo Dry Valleys (MDVs) has been understudied due to lack of a detailed snowfall record. Research has shown that a relationship between snow cover and UW PAR exists, but the extent has never been evaluated in great detail. Although annual snowfall values in the MDVs are low (3 to 50 mm water equivalent annually), trends of increasing snowfall on the continent under future warming conditions could lead to an increased role for snow in regulating UW PAR (and associated primary productivity). Here, I discuss evidence from the …

Building A Better Batture: A Regional Recreational Enhancement Around The Morganza To The Gulf Levee, Taylor N. Fehmel

LSU Master's Theses

Twenty-five years ago, the existing flood protection levees along the Louisiana coastline were removed and construction was started by Terrebonne Levee and Conservation District on a new project called ‘Morganza to the Gulf’ or MTG. This project was undertaken to construct a new flood protection levee system around Louisiana in the communities in Terrebonne and Lafourche Parish. The MTG Levee is one of the first coastal projects in Louisiana to incorporate a risk-based analysis for a double levee system containing both local parish drainage levees and future storm surge levees of MTG. It was designed to protect approximately 250,000 people …

Phylogeny And Evolution Of Swallows (Hirundinidae) With A Transcriptomic Perspective On Seasonal Migration, Clare Elisabeth Brown

LSU Doctoral Dissertations

Evolutionary biology seeks to understand the forces that have generated and shaped patterns of diversity. In this dissertation, I investigated phylogenetic relationships and the evolution of three traits—migration, nest-type, and geographic distribution—in the swallow family (Hirundinidae), a globally distributed group of about 85 species of aerial insectivorous birds. I first applied a dataset of several thousand ultraconserved element (UCE) loci to reconstructing the phylogeny of the New World genus Tachycineta. Three methods of phylogenetic inference produced topologically discordant trees, but post-inference analyses provided evidence that the tree produced by maximum likelihood analysis of a concatenated data matrix is the most …

Population Dynamics And Demographics Of Spotted Seatrout, Cynoscion Nebulosus, Through Spatial Analysis: Towards An Integrative Management Approach, Ashley Melancon Baer

LSU Doctoral Dissertations

Spotted seatrout (Cynoscion nebulosus) is one of the most highly prized sportfish along the Gulf of Mexico coast, particularly in Louisiana. Although spotted seatrout are considered to be well managed and sustainably fished according to the state’s most recent stock assessment, the spatial ecology of this species is largely understudied in Louisiana waters. Acoustic telemetry is an innovative technology that is commonly used to assess the movements and behavior of aquatic species, and can be used as a tool to address the paucity of information on the spatial dynamics of spotted seatrout. The focus of this study was …

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Composition And Ecology Of Avian Communities Along Elevational Gradients In Borneo, Ryan Christian Burner

LSU Doctoral Dissertations

A primary goal of ecology is to explain the diversity and distribution of organisms. Species distributions can be a function of abiotic factors, species interactions, dispersal limitations, and history, but the relative importance of these factors is widely debated. Elevational gradients are useful systems for studying these effects because many of these factors vary predictably with elevation, and because elevational gradients are replicated many times across the earth. However, few quantitative surveys of Southeast Asian bird communities have been conducted along elevational gradients. In this study, I surveyed birds using point counts and measured habitat and temperature across primary forest …

Intraguild Predation: Interactions Between Predators, Pathogens, And Their Shared Resources In Crop Pest Communities, Andrew Jason Flick

LSU Doctoral Dissertations

Crop pest management requires an understanding of the complex interactions among pest species that potentially damage crop yield and species that may be crucial for controlling pest species outbreaks. For example, predators, parasitoids, and pathogens are constantly interacting via their shared prey or hosts. Predators may prefer infected prey, which can be easier to catch; however, infected prey may be less nutritious or even lethal for predators. These interactions then dictate the short-term dynamics of host and pathogen as well as between prey and predator. "How these dynamics change as the species in the system change either empirically or theoretically?" …

Changing Land-Use From Pinus Elliottii To Eucalyptus Bentamii In Southwest Louisiana Affects Understory Vegetation Richness, Diversity, And Functional Diversity Patterns, Andrea De Stefano

LSU Doctoral Dissertations

In the Western Gulf region of the United States cold-tolerant eucalyptus have been explored as pulpwood feedstock. However, non-native plantations may alter understory species diversity, modifying environmental conditions and soil characteristics. Few studies have compared eucalyptus plantations with other ecosystems to understand the impacts of converting these land uses on understory vegetation in the United States. Three plantations were selected: (1) slash pine (Pinus elliottii) established in 2008, (2) slash pine established in 2013, and (3) and Camden white gum (Eucalyptus benthamii) established in 2013. The objectives of this study were to: (1) investigate potential changes …

Speciation And Hybridization In Jamaican-Endemic Streamertail Hummingbirds (Trochilus Polytmus And T. Scitulus), Caroline D. Judy

LSU Doctoral Dissertations

Streamertails hummingbirds (Trochilus polytmus and T. scitulus) are recently diverged sister taxa that appear to have speciated in situ on the island of Jamaica. They are distinguished by male bill color, a secondary sexual trait that is coral red in T. polytmus and jet black in T. scitulus. They hybridize in a narrow zone where their ranges meet in eastern Jamaica. In Chapter 2, I performed a formal population survey of T. scitulus to determine the size of the population, which was unknown. I determined that the total population contains well over 100,000 individuals despite its limited …

An Evaluation Of Sciaenid Growth In The Gulf Of Mexico, Shane Flinn

LSU Master's Theses

Growth models estimate life history parameters that are used in the management of fisheries stocks. The most commonly used growth model in fisheries is the von Bertalanffy growth model (VBGM), yet it has been shown to provide a poor fit for length-at-age data of some species and other models exist. I reviewed 196 peer-reviewed age and growth studies and 50 NOAA stock assessments to examine temporal trends in the use of growth models and model selection in fisheries. I found that the use of multi-model frameworks has increased since the year 2000 and information theoretic approaches are replacing goodness-of-fit and …

A Review Of Current Knowledge Concerning The Breeding And Summer Distribution Of The Cordilleran Flycatcher (Empidonax Occidentalis) In Mexico, Harold F. Greeney, Matthew J. Miller, Charles Van Riper Iii

Occasional Papers of the Museum of Natural Science, Louisiana State University

The Cordilleran Flycatcher (Empidonax occidentalis) is one of many North American birds whose distribution crosses the US–Mexican border and for which little is presently known about summer distribution and breeding biology south of this border. In addition, the Cordilleran Flycatcher presents ornithologists with a number of challenging questions surrounding its taxonomy, migration, distribution, population structure, and species limits. In particular, there remains a good deal of uncertainty concerning the species-level relationships, seasonal movements, and the wintering and breeding distributions of both recognized subspecies of Cordilleran Flycatcher in Mexico. Using field observations, a thorough review of the literature, and …

Impact Of Temperature, Plant Species, And Sorghum Cultivar On The Population Dynamics Of Melanaphis Sacchari, Monique Ferreira De Souza

LSU Doctoral Dissertations

Sugarcane aphid, Melanaphis sacchari Zehner, is now widely established in sorghum, Sorghum bicolor L., production areas of the United States and is an important economic pest. However, detailed studies of temperature, host range and plant resistance effects on the biology and population parameters of the M. sacchari biotype responsible for the sorghum outbreak in the United States have not been performed previously. Therefore, the present study aimed to investigate: 1) How temperatures affect M. sacchari 2) M. sacchari interaction with host plants 3) M. sacchari interaction with sorghum genotypes. The response of M. sacchari to six different constant temperatures (15, …

Determining The Drivers Of Anti-Tropical Distributions Across The Fish Tree Of Life, William Benton Ludt

LSU Doctoral Dissertations

Anti-tropical distributions are those where populations of a single species, or multiple closely related taxa, are distributed outside of, and on opposing sides of, the tropics. These latitudinally disjunct distributions have been noted for over a century. Despite this long history of interest, little has been concluded regarding the actual mechanisms that drive this pattern, with several prominent hypotheses competing with one another in the literature. Here I review the proposed drivers of anti-tropicality, and subsequently test them using fishes with a variety of life history and taxonomic differences. This includes (1) a temperately restricted family with anti-tropical distributions – …

Computational Analysis Of Papionini Evolution Using Alu Insertions, Vallmer Edward Jordan Ii

LSU Doctoral Dissertations

Alu elements are primate specific retrotransposons that have remained active throughout the course of primate evolution. As a result of this sustained mobilization. Alu elements are present in greater copy number in primate genomes than any other transposable element. An average of over one million Alu elements has been identified in every sequenced haplorrhine genome to date. These characteristics qualify Alu elements as ideal characters for studying evolutionary relationship among primates.

The increasing availability of whole genome sequencing data presents novel challenges and opportunities for comparative genomic analyses. Genomic data is now publicly available for most primate species. Such an …

Effects Of Oil On Mollusk And Crustacean Populations, Behavior, And Predator-Prey Interactions, Elizabeth Marie Robinson

LSU Doctoral Dissertations

The Deepwater Horizon blowout and oil spill in April 2010 released ~5 million barrels of oil into the Gulf of Mexico. Approximately 1,773 km of shoreline was oiled along the northern Gulf of Mexico coast, and ~60% of the oiling ended up on Louisiana salt marsh habitat. The objective of this dissertation was to examine the effects of DWH oil on predator-prey relationships between blue crabs and periwinkle snails, as well as mollusk and blue crab population structure. A broad spatial-temporal field study in Barataria and Terrebonne Bays was used to examine the legacy of oil on five species of …

Analysis Of Submerged Aquatic Vegetation Resources Across The Northern Gulf Of Mexico: Communities And Biomass, Eva R. Hillmann

LSU Doctoral Dissertations

Submerged aquatic vegetation (SAV) provides many critical ecosystem services, yet we lack basic information on SAV assemblages, biomass and diversity across expansive coasts such as the northern Gulf of Mexico (nGoM). This research investigated SAV along the nGoM from 2013-2015 examining (1) inter-annual variation in SAV assemblages and biomass across salinity zones and gulf coast eco-regions (Texas Mid-Coast, Texas/LA Chenier Plain, Louisiana Delta, MS/AL), (2) intra-annual variation in SAV assemblages and biomass across salinity zones, (3) response of two species, Ruppia maritima and Myriophyllum spicatum, to salinity and light regimes, and (4) estimated organic carbon stock and storage of …