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Influence Of Hydrological And Environmental Conditions On Mangrove Vegetation At Coastal And Inland Semi-Arid Areas Of The Gascoyne Region, Natasha Robin Dunham

Theses: Doctorates and Masters

Mangrove stands are uncommon within semi-arid climates and rare within inland systems. It is uncertain whether the same environmental variables influence mangroves growing in a semi-arid climate as the trees growing in tropical and sub-tropical areas. Field studies conducted on the ecophysiological responses of the mangrove species Avicennia marina are few; however hydrological regimes are considered the key factor influencing mangrove stand zonation, structure and individual tree growth. The Gascoyne region of Western Australia provides a unique opportunity to investigate whether mangroves growing within an inland semi-arid environment display similar growth patterns and ecophysiological responses to their coastal counterparts.

This …

The Movement Ecology Of Seagrasses, Kathryn Mcmahon, Kor-Jent Van Dijk, Leonardo Ruiz-Montoya, Gary A. Kendrick, Siegfried L. Krauss, Michelle Waycott, Jennifer Verduin, Ryan Lowe, John Statton, Eloise Brown, Carlos Duarte

Research outputs 2014 to 2021

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history …

The Conservation Value Of Karst Dolines For Vascular Plants In Woodland Habitats Of Hungary: Refugia And Climate Change, Zoltán Bátori, János Csiky, Tünde Farkas, E. Anna Vojtkó, László Erdős, Dániel Kovács, Tamás Wirth, László Körmöczi, András Vojtkó

International Journal of Speleology

Limestone (karst) surfaces in Hungary are rich in dolines, in which many endangered vascular plant species occur. To date, the majority of studies dealing with doline vegetation have focused on the local rather than the landscape level, without using comparative data from other areas. However, in this study we aimed to compare the vegetation pattern and species composition of dolines under different climate regimes of Hungary with regard to regional species pools. The fieldwork was carried out between 2005 and 2012. Twenty dolines were selected in the Mecsek Mountains (southern Hungary) and nine dolines in the Aggtelek Karst area (northern …

Soil Seed Banks Of Fringing Salt Lake Vegetation In Arid Western Australia - Density, Composition And Implications For Postmine Restoration Using Topsoil, Eddie J. Van Etten, Brett Neasham, Sarah Dalgleish

Research outputs 2014 to 2021

Although studies of seed banks in arid ecosystems are commonplace, they are lacking for the large arid zone of Western Australia. Across the six major plant communities fringing a large salt lake within this zone, topsoil (0-5 cm depth) was collected from 12 to 36 sites per community. Samples were dried, spread out on a bed of vermiculite in seedling trays and placed in a well-watered glasshouse to determine the readily germinable component of the soil seed bank. Subsamples of topsoil were treated with smoke water, hot water or flooding to help determine seed bank of species with dormancy mechanisms. …

Behavioural Ecology Of The Black-Flanked Rock-Wallaby (Petrogale Lateralis Lateralis): Refuge Importance In A Variable Environment, Craig Pentland

Theses: Doctorates and Masters

The black-flanked rock-wallaby (Petrogale lateralis lateralis) has suffered a significant decline in its distribution in Western Australia. This has been attributed to introduced predators (predominantly the red fox) and herbivores, fire, and habitat destruction due to clearing. Although since 2001 the Department of Environment and Conservation (DEC) had begun to reintroduce this species back into its former range, little was known of the behavioural ecology of this species. Fox control in the 1980s and 1990s resulted in population increases of rock-wallabies on several reserves in the central wheatbelt of WA. However, recently these populations have rapidly declined despite continuing fox …

Systematics And Biogeography Of The Australian Burrowing Freshwater Crayfish Genus Engaewa Riekk (Decapoda: Parastacidae), Quinton Burnham

Theses: Doctorates and Masters

The overall aim of this study was to explore the systematics and biogeographic patterns of the freshwater crayfish genus Engaewa Riek, a strongly burrowing freshwater crayfish restricted to the coastal corner of south-western Australia (SWA). The genus Engaewa is a Gondwanan relict with great potential as a marker of historical processes, due to its high habitat specificity and low dispersal ability. This study comprises an extensive taxonomic and phylogenetic revision of the genus Engaewa (using both molecular and morphological data), a detailed study of its distribution and uses the knowledge gained to explore biogeographic patterns in the biodiversity hotspot of …

The Impact Of Multiple Nursery Areas On The Population Structure Of Atlantic Menhaden, Brevooria Tyrannus, Kristen A. Anstead

OES Theses and Dissertations

Understanding the population structure and patterns of connectivity in marine fishes is essential when making predictions about a species' resiliency and persistence in an increasingly changing environment. The Atlantic Menhaden Brevoortia tyrannus is a clupeid that plays a critical role in the marine food web and supports one of the largest fisheries on the US East Coast. In addition to a decrease in overall numbers and spawning stock biomass, recruitment levels have remained low since the 1990s. Menhaden use numerous estuaries along the Atlantic coast for juvenile development before recruiting to the adult population and the contribution of each of …

Endogenous Ros Levels In C. Elegans Under Exogenous Stress Support Revision Of Oxidative Stress Theory Of Life-History Tradeoffs, Samson W. Smith, Leigh C. Latta Iv, Dee R. Denver, Suzanne Estes

Biology Faculty Publications and Presentations

Background: The oxidative stress theory of life-history tradeoffs states that oxidative stress caused by damaging free radicals directly underpins tradeoffs between reproduction and longevity by altering the allocation of energetic resources between these tasks. We test this theory by characterizing the effects of exogenous oxidative insult and its interaction with thermal stress and diet quality on a suite of life-history traits and correlations in Caenorhabditis elegans nematodes. We also quantify demographic aging rates and endogenous reactive oxygen species (ROS) levels in live animals.

Results: Our findings indicate a tradeoff between investment in reproduction and antioxidant defense (somatic maintenance) consistent with …

Partitioning The Fitness Components Of Rna Populations Evolving In Vitro, Carolina Diaz Arenas, Niles Lehman

Chemistry Faculty Publications and Presentations

All individuals in an evolving population compete for resources, and their performance is measured by a fitness metric. The performance of the individuals is relative to their abilities and to the biotic surroundings – the conditions under which they are competing – and involves many components. Molecules evolving in a test tube can also face complex environments and dynamics, and their fitnessmeasurements should reflect the complexity of various contributing factors as well. Here, the fitnesses of a set of ligase ribozymes evolved by the continuous in vitroevolution system were measured. During these evolution cycles there are three different catalytic …

Effects Of Understory Vegetation And Litter On Plant Nitrogen (N), Phosphorus (P), N∶P Ratio And Their Relationships With Growth Rate Of Indigenous Seedlings In Subtropical Plantations, Jun Wang, Dafeng Hui, Hai Ren, Zhanfeng Liu, Long Yang

Biology Faculty Research

Establishing seedlings in subtropical plantations is very important for forest health, succession and management. Information on seedling nutrient concentrations is essential for both the selection of suitable indigenous tree species to accelerate succession of the established plantation and sustainable forest management. In this study, we investigated the concentrations of nitrogen ([N]), phosphorus ([P]), and N∶P ratio in leaves, stems and roots of seedlings of three indigenous tree species (Castanopsis chinensis, Michelia chapensis and Psychotria rubra) transplanted with removing or retaining understory vegetation and litter at two typical subtropical forest plantations (Eucalyptus plantation and native species plantation). We also measured the …

Statistical And Comparative Phylogeography Of Mexican Freshwater Taxa In Extreme Aquatic Environments, Lyndon M. Coghill

LSU New Orleans Theses and Dissertations

Phylogeography aims to understand the processes that underlie the distribution of genetic variation within and among closely related species. Although the means by which this goal might be achieved differ considerably from those that spawned the field some thirty years ago, the foundation and conceptual breakthroughs made by Avise are nonetheless the same and are as relevant today as they were two decades ago. Namely, patterns of neutral genetic variation among individuals carry the signature of a species’ demographic past, and the spatial and temporal environmental heterogeneity across a species’ geographic range can influence patterns of evolutionary change. Aquatic systems …

Assessing The Responses Of Adult, Juvenile, And Larval Fish Assemblages To The Closure Of The Mississippi River Gulf Outlet, An Artificial Tidal Pass In Southeastern Louisiana, Rebecca Weatherall Cope

LSU New Orleans Theses and Dissertations

The creation of the Mississippi River Gulf Outlet (MRGO) in 1963 by the U.S. Army Corps of Engineers (USACE) represents one of the most catastrophic, anthropogenic stressors ever to impact the Lake Pontchartrain estuary in southeastern Louisiana, USA. The artificial tidal pass provided a direct route from the Gulf of Mexico to New Orleans. It allowed for high saline waters to enter Lake Pontchartrain, resulting in detrimental changes to the biotic community of the Lake and surrounding wetland areas. In July 2009, the USACE closed the MRGO in hopes of restoring natural ecosystems. This study assesses changes in the adult, …

The Effects Of Salinity, Ph, Temperature, And Dissolved Oxygen On Sensitivity Of Pcr Identification Of T4 Bacteriophage, Joesph F. Cannon, Nicholas A. Thurn, Paul E. Richardson

Journal of the South Carolina Academy of Science

Bacteriophages are used as indicators of pathogenic bacteria in drinking, and wastewaters. They also show potential in limiting aquatic bacterial populations through their lytic properties. The effect of different water characteristics (salinity, pH, dissolved oxygen, and temperature) on the sensitivity of the PCR identification of virus particles were analyzed to determine at what levels bacteriophage can be detected in environmental samples. Results from this preliminary study indicate that a PCR bacteriophage detection technique has potential as a relatively efficient and economical indicator of coliform contamination in multiple aquatic environments. While further evaluation is needed, the protocol appears to function in …

The Influence Of Snowmobile Trails On Coyote Movements During Winter In High-Elevation Landscapes, Eric M. Gese, Jennifer L. Burghardt Dowd, Lise M. Aubry

Wildland Resources Faculty Publications

Competition between sympatric carnivores has long been of interest to ecologists. Increased understanding of these interactions can be useful for conservation planning. Increased snowmobile traffic on public lands and in habitats used by Canada lynx (Lynx canadensis) remains controversial due to the concern of coyote (Canis latrans) use of snowmobile trails and potential competition with lynx. Determining the variables influencing coyote use of snowmobile trails has been a priority for managers attempting to conserve lynx and their critical habitat. During 2 winters in northwest Wyoming, we backtracked coyotes for 265 km to determine how varying snow characteristics influenced coyote movements; …

Cellular Roles Of Dna Polymerase Beta, Sreerupa Ray, Miriam-Rose Menezes, Ali Senejani, Joann Balazs Sweasy

Biology and Environmental Science Faculty Publications

Since its discovery and purification in 1971, DNA polymerase ß (Pol ߆) is one of the most well-studied DNA polymerases. Pol ß is a key enzyme in the base excision repair (BER) pathway that functions in gap filling DNA synthesis subsequent to the excision of damaged DNA bases. A major focus of our studies is on the cellular roles of Pol ß. We have shown that germline and tumor-associated variants of Pol ß catalyze aberrant BER that leads to genomic instability and cellular transformation. Our studies suggest that Pol ß is critical for the maintenance of genomic stability and that …

Soil Development And Vegetation Response To Removal Of A Small Dam, Lassen Volcanic National Park, California, Stephanie Kay Rohdy

Dissertations and Theses

Dam removal is increasing as dams age, yet little is understood about the pedogenic response to dam removal. This study reports on the edaphic changes of reservoir sediments and vegetation cover one year following removal of a small earthen dam in Northern California. In August 2012, I sampled surface sediments from the former Dream Lake reservoir in Lassen Volcanic National Park, and compared their physical and chemical properties with soil samples from two reference sites. I also estimated percent cover of vegetation in the former reservoir and reference sites. My results show that the reservoir was under reduced conditions, as …

Development And Application Of A Gis-Based Long Island Sound Eelgrass Habitat Suitability Index Model, Jamie M.P. Vaudrey, Justin Eddings, Christopher Pickerell, Lorne Brousseau, Charles Yarish

Department of Marine Sciences

The primary objectives of the Eelgrass Habitat Suitability Index Model (EHSI Model) are to assist in the evaluation of sites being considered for eelgrass restoration efforts in the Long Island Sound (LIS) area and to identify areas where water quality issues reduce or eliminate the potential for natural eelgrass colonization. To achieve this goal, geospatial processing of data available from the Long Island Sound area was conducted using ArcGIS v10.0 including the 3D Analyst and Spatial Analyst extensions. The result is a series of maps presented in this report and a GIS-based model available for users to interact with the …

First State Record And Interdiction For The Wood Slave, Hemidactylus Mabouia (Moreau De Jonnès 1818) (Gekkonidae), In Maryland, Usa., Louis A. Somma, William L. Grogan Jr.

Papers in Herpetology

The Wood Slave, Hemidactylus mabouia (Moreau de Jonnès 1818; Fig. 1), is indigenous to Africa south of the Sahara, with nonindigenous populations established in Cape Verde, Mexico, much of Central and South America, numerous localities in the Caribbean, perhaps Madagascar, and at least 21 counties in Florida, USA (Carranza and Arnold 2006; Kraus 2009; Krysko et al. 2011a, 2011b; Meshaka 2011; Powell and Henderson 2012). Recently, H. mabouia has successfully invaded temperate regions of southern Africa and northern peninsular Florida (Alexander and Marais 2007, Krysko and Somma 2007).

On 20 December 2012, Brian R. Grogan and Shane Forsythe collected and …

Photo-Identification Methods Reveal Seasonal And Long-Term Site-Fidelity Of Risso’S Dolphins (Grampus Griseus) In Shallow Waters (Cardigan Bay, Wales), Marijke N. De Boer, Josephine Clark, Mardik F. Leopold, Mark P. Simmonds, Peter J.H. Reijnders

Ecology Collection

A photo-identification study on Risso’s dolphins was carried out off Bardsey Island in Wales (July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: 1) mark-recapture of well-marked dolphins using a “closed-population” model; and 2) a census technique based on the total number of iden-tified individual dolphins sighted over the study period. The mark-recapture estimates of 121 (left sides; 64 - 178, 95% CI; CV 0.24) and 145 dolphins (right sides; 78 - 213, 95% CI; CV 0.24) closely matched the census technique estimates (population size of 90 - 151). It was found that the dolphins …

Census And Mapping Of Chorro Creek Bog Thistle In Reservoir Canyon, San Luis Obispo, Ca, Tyler Michael Lutz

Biological Sciences

Chorro Creek bog thistle (Cirsium fontinale var. obispoense) is a federally endangered variety of Fountain thistle endemic to western San Luis Obispo County. The U.S. Fish and Wildlife Service knows of nineteen populations, many with multiple colonies. A population was discovered in the Reservoir Canyon Natural Reserve in 2001, but has not been monitored or described since the time of its discovery. In fall of 2013, a census of the population was performed, the four colonies were mapped, and a floristic survey was conducted. A field experiment was initiated to determine if reducing the riparian canopy coverage can …

Landscape Genetics Of The Marbled Salamander (Ambystoma Opacum) At Mammoth Cave National Park, James Kyle Martin

Masters Theses & Specialist Projects

Habitat connectivity is important to maintain in order to prevent loss of genetic diversity, reduce inbreeding depression, and decrease extinction risk in threatened or endangered species. Here I present a landscape genetics study on marbled salamanders (Ambystoma opacum) in highly connected forested habitat at Mammoth Cave National Park. This investigation of gene flow among ponds within a mostly continuous landscape provides data that can be compared with patterns observed in more fragmented landscapes. These comparisons can provide a means of investigating the separate effects of structural and functional habitat connectivity on amphibian genetic population structure. Structural connectivity refers to the …

Interference In White Bass Reproduction By Two Introduced Predators In Barren River Lake, Kentucky, Jacob Franklin Fose

Masters Theses & Specialist Projects

White bass Morone chrysops are native to the Mississippi River and its tributaries. This range includes the Barren River in south central Kentucky. Over the last thirty years, the population of white bass in Barren River Lake, a reservoir of the Barren River, has been in decline. During that same time, two congeners of white bass have been introduced to the lake. Hybrid striped bass Morone chrysops × Morone saxatilis were introduced in 1979 and yellow bass Morone mississippiensis were first discovered in 2000. Due to the similar life histories and spawning strategies of all three Morone species, I hypothesized …

Dual Capture Of A Piñon Deer Mouse And A Silky Pocket Mouse Resulting In Consumption Of The Smaller Animal, Jon C. Pigage, Roger D. Peyton

The Prairie Naturalist

Intraspecific dual captures of rodents are uncommon, but not rare. There are several reports of brown rats (Rattus norvegicus), white-footed deer mice (Peromyscus leucopus), North American deer mice (P. maniculatus), western harvest mice (Reithrodontomys megalotis) and meadow voles (Microtus pennsylvanicus) caught simultaneously in the same trap (i.e. a door-closing live-trap; Davis 1955, Getz 1961, Blaustein and Rothstein 1978, Jenkins and Llewellyn 1981, Novak 1983). Some reports are incidental whereas others are interpreted as social associations or bonding between conspecifics. Interspecific dual captures are rarely reported in the literature. The earliest report of …

A Simple Device For Measuring The Minimum Current Velocity To Maintain Semi-Buoyant Fish Eggs In Suspension, Julias S. Mueller, Brandon D. Cheek, Qingman Chen, Jillian Groeschel, Shannok K. Brewer, Timothy B. Grabowski

The Prairie Naturalist

Pelagic broadcast spawning cyprinids are common to Great Plains rivers and streams. This reproductive guild produces non-adhesive semi-buoyant eggs that require sufficient current velocity to remain in suspension during development. Although studies have shown that there may be a minimum velocity needed to keep the eggs in suspension, this velocity has not been estimated directly nor has the influence of physicochemical factors on egg buoyancy been determined. We developed a simple, inexpensive flow chamber that allowed for evaluation of minimum current velocity needed to keep semi-buoyant eggs in suspension at any time frame during egg development. The device described here …

Red-Tailed Hawk Nesting In Kansas: Influence Of Landscape Characteristics, William Langley

The Prairie Naturalist

Factors that affect nest site selection in red-tailed hawks (Buteo jamaicensis) include the physical features surrounding the nest and landscape characteristics. Features surrounding nests include: tree height, tree diameter (dbh), percent canopy cover, slope, nest openness, and density of woody plants or shrubs (Titus and Mosher 1981, Bechard et al. 1990, Tietje et al. 1997, Actkinson et al. 2007). Landscape characteristics that influence nest-site selection by red-tailed hawks vary across regions. In Georgia, red-tailed hawks selected nest site in areas with greater area of agriculture and open pasture (Moorman and Chapman 1996), whereas in Oklahoma prairies, the hawks …

Use Of Seeded Exotic Grasslands By Wintering Birds, Andrew D. George, Timothy J. O'Connell, Karen R. Hickman, David M. Lesliee Jr.

The Prairie Naturalist

Despite widespread population declines of North American grassland birds, effects of anthropogenic disturbance on wintering habitat of this guild remain poorly understood. We compared avian abundance and habitat structure in fields planted to the exotic grass Old World bluestem (Bothriochloa ischaemum; OWB) to that in native mixed-grass prairie. During winters of 2007–2008 and 2008–2009, we conducted bird and vegetation surveys in six native grass and six OWB fields in Garfield, Grant, and Alfalfa counties, Oklahoma. We recorded 24 species of wintering birds in native fields and 14 species in OWB monocultures. While vegetation structure was similar between field …

Whooping Cranes Consume Plains Leopard Frogs At Migratory Stopover Sites In Nebraska, Keith Geluso, Brad T. Krohn, Mary J. Harner, Michael J. Assenmacher

The Prairie Naturalist

Whooping cranes (Grus americana) currently consist of a single, wild population that migrates annually from breeding grounds at Wood Buffalo National Park, Canada, to wintering grounds on and around the Aransas National Wildlife Refuge along the Texas coast, USA (NRC 2005). This population reached a low of less than 20 individuals in 1941 (Allen 1952) but has rebounded to over 250 individuals (Chavez-Ramirez and Wehtje 2012, Gil-Weir et al. 2012). Whooping cranes migrate approximately 4,000 km each spring and autumn, traversing much of the North American Great Plains (Lewis 1995) and periodically landing along rivers, wetlands, and other …

Conserving The Land Of The Giants: Critical Threats To Asian Elephant Habitat In Sri Lankan Protected Areas, Christie Sampson

All Theses

Grasslands habitats are hypothesized to be a critical resource for the endangered Asian elephant (Elephas maximus) throughout its range. However, this hypothesis has not been rigorously tested. My study examined elephant habitat selection in Sri Lanka to determine the importance of grassland versus other local habitats, and how livestock abundance, fire, and the invasive plant Lantana camara affect the relative abundance of elephants within habitats. My research was conducted in two protected areas in Sri Lanka, Udawalawe National Park (UNP) and Hurulu Forest Reserve (HR). I used distance-sampling on a total of 50.8 km of dung line-transects in the four …

A Seasonal, Density-Dependent Model For The Management Of An Invasive Weed, Esther Shyu, Eleanor A. Pardini, Tiffany M. Knight, Hal Caswell

Biology Faculty Research

The population effects of harvest depend on complex interactions between density dependence, seasonality, stage structure, and management timing. Here we present a periodic nonlinear matrix population model that incorporates seasonal density dependence with stage-selective and seasonally selective harvest. To this model, we apply newly developed perturbation analyses to determine how population densities respond to changes in harvest and demographic parameters. We use the model to examine the effects of popular control strategies and demographic perturbations on the invasive weed garlic mustard (Alliaria petiolata). We find that seasonality is a major factor in harvest outcomes, because population dynamics may …

Homing Behavior In Response To Displacement And Orientation Of The Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Barnegat Bay, New Jersey, Nicole M. Lainhart

Biology Theses

Increasing urbanization of the Barnegat Bayestuary in New Jersey has subjected northern diamondback terrapins to substantial habitat loss. Understanding whether terrapins have homing behavior, and determining the types of orientation cues they use to aid in this behavior, is important for conservation management. To test their homing behavior, nine non-gravid female terrapins were outfitted with biotelemetry tracking devices and data loggers and were displaced 4 km north and/or south. Eight of nine terrapins successfully returned home; the one terrapin that did not return home was inadvertently captured in a crab pot. Urbanization and shoreline development of the north displacement location …