Digital Commons Network^™

Terrestrial Habitat Requirements Of Nesting Freshwater Turtles, D. A. Steen, J. P. Gibbs, K. A. Buhlman, J. L. Carr, B. W. Compton, J. D. Congdon, J. S. Doody, J. C. Godwin, Kerry L. Holcomb, D. R. Jackson, F. J. Janzen, G. Johnson, M. T. Jones, J. T. Lamer, T. A. Langen, M. V. Plummer, J. W. Rowe, R. A. Saumure, J. K. Tucker, D. S. Wilson

All Faculty Scholarship for the College of the Sciences

Because particular life history traits affect species vulnerability to development pressures, cross-species summaries of life history traits are useful for generating management guidelines. Conservation of aquatic turtles, many members of which are regionally or globally imperiled, requires knowing the extent of upland habitat used for nesting. Therefore, we compiled distances that nests and gravid females had been observed from wetlands. Based on records of > 8000 nests and gravid female records compiled for 31 species in the United States and Canada, the distances that encompass 95% of nests vary dramatically among genera and populations, from just 8 m for Malaclemys to …

The Ecological Role Of Rhizophytic Green Algae In Soft-Bottom Habitats, Laura Bedinger

USF Tampa Graduate Theses and Dissertations

Rhizophytic algae are large, abundant primary producers throughout tropical and subtropical areas worldwide where they grow as an understory in seagrass beds, as well as form mixed or monospecific beds of exclusively rhizophytic algal species. In this dissertation, "rhizophytic algae" refers to coenocytic green algae (Chlorophyta) in the order Bryopsidales that use a net of rhizoids to anchor in unconsolidated sediments. In the development of seagrass beds, rhizophytic algae colonize bare patches and are thought to facilitate seagrass colonization by stabilizing sediments and providing organic matter. However, despite their prominence little is known about many aspects of the ecology of …

Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii

Dissertations

Vibrio parahaemolyticus (V_p) is a gram-negative bacterium found naturally in marine and estuarine environments. V_p is found in oysters including those which are later consumed by the public. Sub-populations of potentially virulent Vp contain specific virulence factors and are relevant human pathogens capable of causing gastroenteritis, wound infection, and death. The tdh and trh genes, both encoding hemolysins, have been correlated with the majority of clinical V_p isolates but have not been shown to be the definitive virulence factors.

A total of 146 V_p isolates from the northern Gulf of Mexico were collected and probed …

Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels

Dissertations

Hypoxia occurs in estuaries of northern Gulf of Mexico and world-wide, with increasing frequency/severity via eutrophication and anthropogenic influences. Hypoxia inducible factors (HIFs) form transcriptional complex and bind DNA at hypoxia responsive elements (HREs) in promoter regions of genes needed for systemic and cellular adaptation of fish to low dissolved oxygen (hypoxia, DO <2.0 mg/ml). Hypoxia-induced activation of HIF-αs can lead to a cascade of downstream activation, such as erythropoietin (EPO). Return to normal DO levels (normoxia), prolyl hydroxylases (PHDs) are activated to degrade HIF-αs back to baseline. Fish are affected by environmental estrogen mimics, like 4-tert-octylphenol (4tOP), binding estrogen receptor alpha (ERα) at estrogen responsive elements (EREs) and activating genes vitellogenin (VTG). Previous research showed overlap or crosstalk between these two mechanistic pathways. Hypoxia triggers unknown factors regulating ERE-mediated ERα signaling pathway, and stressor combinations could increase/decrease hypoxic or endocrine pathway. Research examined molecular/physiological effects of hypoxia (acute and chronic, moderate and severe) and 4tOP (~60μg/L)on adult male and/or female sheepshead minnow (Cyprinodon variegatus). Three genes identified, cloned, and sequenced (HIF-1α, HIF-2α, and PHD3), plus previously identified genes EPO and VTG, were examined in liver/testes exposed to hypoxia and/or 4tOP for cellular/physiological changes. Endpoints examined included mRNA expression from real-time PCR of HIF-1α, HIF-2α, PHD3, EPO, and VTG using cDNA from total RNA extracts, and microarray analyses of genes expressed during the transition from hypoxia back to normoxia. Phylogenetic analyses confirmed isolation of two HIF-α isofoms (HIF-1α and HIF-2α) and the PHD3 isoform. Significant up-regulation of PHD3 occurred within 10 hrs of chronic hypoxia, and persisted when severe (1.5 mg/L) and declined when moderate (~2.5mg/L). Significant up-regulation of HIF-1α and EPO occurred within 30 minutes to 2 hours of onset of acute severe and very severe (~1.08mg/L) hypoxia. Hypoxia acted similar to an estrogen mimic, with huge up-regulation of VTG gene expression in males, and increased VTG levels (additive effect) when hypoxia was combined with 4tOP. Microarray analyses showed 125 genes with significant transcriptional change, with up- or down-regulation from transitions of: (1) hypoxia (72 hrs) to normoxia (74 hrs) and (2) hypoxia+4tOP (72 hrs) to normoxia+4tOP (74 hrs).

Comparison Of Creel Survey Data To Traditional Sampling Techniques In Pit-Lake Fisheries Of Muhlenberg County, Kentucky, Derek L. Rupert

Masters Theses & Specialist Projects

Populations of largemouth bass, Micropterus salmoides, and bluegill, Lepomis macrochirus, were evaluated from five pit-lakes in Muhlenberg County, Kentucky, to determine if accurate proportional stock density (PSD) data can be obtained from a mandatory creel survey. It was hypothesized that the proportion of stock-to-quality (300-400mm) and quality (+400mm) largemouth bass from four years (2007-2010) of creel survey data would be statistically similar to those generated through on-site sampling in 2011. Fish were collected via a combination of gill netting, seining, hook-and-line fishing, and boat-mounted electro-fishing. In two of the pit-lakes, the sampling-generated length frequency data was not significantly …

The Herring River Estuary: Understanding Salt Marsh Restoration And How To Predict The Response Of Phragmites Australis To Increased Tidal Flow, Theresa Murphy

Senior Honors Projects

My presentation invites you to learn about what is involved in planning a salt marsh restoration project. The Herring River Estuary is a disturbed salt marsh ecosystem at Cape Cod National Seashore which has been diked since 1909. The National Park Service (NPS), in cooperation with many partners, is engaged in efforts to restore the now impacted 1,100 acre estuary by re-introducing tidal flow. There is significant complexity involved in trying to restore such an intricate system- from the multitude of environmental factors to important social and economic consequences. There are also several benefits to restored tidal flow. My thesis …

Increase In Ponderosa Pine Density In The Nebraska Sandhills: Impacts On Grassland Plant Diversity And Productivity, Alexa Armstrong

Department of Environmental Studies: Undergraduate Student Theses

Increase in woody species encroachment into semi-arid grasslands and savannas has been of great concern at a global level. Temperature and precipitation are key factors determining vegetation cover; however other factors, such as fire regime and grazing may be at play in semi-arid ecosystems. Historically, in Nebraska’s semi-arid grasslands, woody species have been controlled by periodic fires. Changes in social values and land use, fire suppression, overgrazing, increased N deposition, and climate change, have attributed to the observed shift from grasslands to shrublands or woodlands. The primary objectives of this study were to determine the impacts of Ponderosa pine ( …

Integrating Ecology And Economics For Restoration: Using Ecological Indicators In Valuation Of Ecosystem Services, Eric T. Schultz, Robert Johnston, Kathleen Segerson, Elena Y. Besedin

EEB Articles

Because it can uniquely furnish insights into nonuse values for ecosystem services, survey-based Stated Preference (SP) valuation is widely used to estimate the benefits of ecological restoration. SP surveys ask respondents to select among restoration options yielding different ecological outcomes. This review examines the representation of ecological outcomes in SP studies seeking to quantify values for restoration of aquatic ecosystems. To promote the validity of ecological indicators used in SP valuation, we identified four standards: indicators should be measurable, interpretable, applicable, and comprehensive. We reviewed recent SP studies estimating the value of aquatic ecosystem services to assess whether ecological indicators …

Territories,Territoriality, And Conservation Of The Louisiana Waterthrush And Its Habitat, The Watershed Of The Upper Buffalo National River, Leesia Cheryl Marshall

Graduate Theses and Dissertations

The Louisiana Waterthrush, Parkesia motacilla, is a migratory wood-warbler and breeding season resident of the eastern United States. Males defend breeding territories that extend linearly along clear, fast-flowing, gravel-bottomed, forest streams. Defense includes two song types, primary and extended song. As riverine specialists, birds rely upon aquatic invertebrates as prey and riparian habitat features for nesting. They use a unique foraging maneuver, leaf-pulling, that involves picking up or pulling a leaf from water, and turning it over to search for prey. Their relationship with riparian habitat introduces potential for Louisiana Waterthrushes to serve as indicators of stream health. The …

Stable Isotope Analysis (Delta Nitrogen-15 And Delta Carbon-13) And Bioenergetic Modeling Of Spatial-Temporal Foraging Patterns And Consumption Dynamics In Brown And Rainbow Trout Populations Within Catch-And-Release Areas Of Arkansas Tailwaters, Jon M. Flinders

Graduate Theses and Dissertations

I examined spatial and temporal consumption dynamics using an energy intake model and a bioenergetics model of rainbow trout, Oncorhynchus mykiss, and brown trout, Salmo trutta, within three catch-and-release (C-R) areas in Bull Shoals and Norfork tailwaters to determine whether trout populations were limited by food supply. I also examined the seasonal and ontogenetic shifts in the foraging patterns of brown and rainbow trout within these areas using gut content analysis (GCA) and stable isotope analysis (SIA) of C and N. I examined 605 brown trout and 768 rainbow trout for GCA and SIA at Bull Shoals, Norfork, …

Natural And Constructed Wetlands For Ecosystem And Engineering Services In The Arid And Semi-Arid Regions, Achyut Raj Adhikari

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Las Vegas Wash (LVW) has undergone significant wetlands degradation and soil erosion over the past thirty years due to increasing flow resulting from urbanization and large rainfall events in the Las Vegas Valley Watershed. The increased flow and associated pollution load in the LVW and its adverse impact in Lake Mead have alerted stakeholders to pay a greater attention to explore alternative measures for rehabilitation of wetland ecosystems. This dissertation, using the case of changes in LVW, analyzes and describes ecological and engineering services provided by wetlands in arid and semi-arid regions and provides a knowledge base that can …

Prehistoric Foraging Strategies In The Piute Valley Of Southern Nevada, Christopher Alan Brosman

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Piute Valley of Southern Nevada is an incredibly diverse but arid zone in the eastern portion of the Mojave Desert. Most of this diversity can be attributed to the elevation shifts ranging from the Colorado River basin to the peaks of the surrounding mountain ranges. These peaks and valleys provide a multitude of resource zones in which prehistoric hunter-gatherers could provision themselves throughout the year. For this thesis I have used archaeological survey, paleo-climate models, life-sciences data and ethnographic research to perform an in-depth land use analysis of prehistoric forager adaptations to this challenging but life-sustaining environment.

Recent investigations …

The Ecological Roles Of Podostemum Ceratophyllum And Cladophora In The Habitat And Dietary Preferences Of The Riverine Caddisfly Hydropsyche Simulans, Brenna Tinsley

Mahurin Honors College Capstone Experience/Thesis Projects

The net-spinning caddisfly Hydropsyche simulans can be a common inhabitant of shallow reaches in riverine systems, and is easily the most common hydropsychid in the upper Green River, Kentucky. This study was performed in summer 2011 and focused on two main questions: 1. Do the larvae of the riverine caddisflies H. simulans and Cheumatopsyche preferentially inhabit dense patches of P. ceratophyllum compared to bare substrates in the upper Green River?, and 2. Do larvae of H. simulans and Cheumatopsyche consume the filamentous alga Cladophora during the annual late summer algal bloom in the upper Green River? Densities of both hydropsychid …

Productivity And Habitat Features Of Swainson's Hawks (Buteo Swainsoni) Nesting In Suburban And Agricultural Areas Of Southwest Idaho, Steven Edward Alsup

Boise State University Theses and Dissertations

I compared nesting success and productivity of Swainson’s Hawks nesting in suburban and agricultural areas in southwest Idaho to assess the effects of land use change on Swainson’s Hawk reproduction. I also evaluated habitat parameters and land use patterns around nesting areas to determine if nest site, habitat, and/or landscape features were related to reproductive success in Swainson’s Hawks. I recorded habitat characteristics, nest tree characteristics, distances to four habitat features, and disturbance types, as well as land use patterns within a 1500m radius around nest trees to assess any differences in nest site characteristics, habitat features, and/or landscape features …

Ribosomal Rna Gene-Based And Multigene Phylogenies Of Smittium (Harpellales) And Allies—Toward Unraveling Relationships Among Early-Diverging Fungi, Yan Wang

Boise State University Theses and Dissertations

Smittium is one of the oldest members of the Harpellales, a group commonly referred to as the “gut fungi”. Gut fungi are endosymbiotic microorganisms that live in the digestive tracts of various Arthropods, worldwide. During the 75 years since the first species, Smittium arvernense, was described, Smittium has increased in number and now includes 81 species. Research on this genus has also helped to advance our understanding of the gut fungi, by serving as a “model” for laboratory studies of the fungal trichomycetes. Many isolates of Smittium have been used for ultrastructural, physiological, host feeding, serological, as well as …

American Pika (Ochotona Princeps): Persistence And Activity Patterns In A Changing Climate, Cody P. Massing

Master's Theses

An increasing amount of evidence suggests that as temperatures increase, montane animals are moving upward in elevation (IPCC 2007, Parmesan and Yohe 2003). As suitable habitats rise in elevation and then disappear altogether, these animals could be pushed to extinction. The American pika, Ochotona princeps, is a montane mammal that lives in western North America, usually at elevations above 1500 m (Smith and Weston 1990). Recent evidence suggests that pika population numbers are dropping in response to rising temperatures (Beever et al. 2010). The pika is a small herbivorous lagomorph, a relative of hares and rabbits. Its habitat is …

A Coupled Human And Natural Systems Approach To Understanding An Invasive Frog, Eleutherodactylus Coqui, In Hawaii, Emily A. Kalnicky

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human activities worldwide have altered nature in ways that create new combinations of species and environmental processes. To understand so-called "novel ecosystems" it is important to consider both the natural and the societal factors that shape them, and how those factors are interconnected or "coupled." We used such an approach to explore options for managing a non-native invasive frog, the coqui, which has become established on the island of Hawaii and threatens to spread to other parts of the state.

The nighttime calls of the coqui create a nuisance for property owners when populations become dense enough, as often occurs …

Landscape And Habitat Attributes Influencing Beaver Distribution, Ryan John Leary

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Removal of beaver across the North America landscape from the 1600s through the 1800s has played a major influence on the alteration of stream and riparian resources. Degradation of riparian habitats has negatively impacted many wildlife and fish species, including species listed under the Endangered Species Act. The ability of beavers to modify stream ecosystems offers a unique opportunity to restore these habitats. Many private and government agencies are working towards using beaver as a restoration tool, not only for better functioning ecosystems but also to benefit humans. Taking the big picture look, beaver and their ability to modify the …

The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Composition, Stephanie M. Cobbold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecologists strive to identify the mechanisms that drive the identity and abundance of species in different locations, because a better understanding of such factors enables them to better predict the effects of habitat modification on organisms, and to identify landscapes in which species are likely to benefit from conservation interventions. However, there is still no consensus on the mechanisms behind geographical variation in species diversity. The primary objective of this dissertation was to focus on spider assemblages to investigate how the fine-scale habitat associations of organisms may drive the composition of their communities at larger scales. Research was conducted in …

Spatio-Temporal Differentiation And Sociality In Spiders, Jessica Purcell, João Vasconcellos-Neto, Jeffrey Alan Fletcher, Marcelo O. Gonzaga, Leticia Avilés

Complex Systems Faculty Publications and Presentations

Species that differ in their social system, and thus in traits such as group size and dispersal timing, may differ in their use of resources along spatial, temporal, or dietary dimensions. The role of sociality in creating differences in habitat use is best explored by studying closely related species or socially polymorphic species that differ in their social system, but share a common environment. Here we investigate whether five sympatric Anelosimus spider species that range from nearly solitary to highly social differ in their use of space and in their phenology as a function of their social system. By studying …

The Effects Of Invasive Grasses On The Survival And Germination Of Native Forbs, Rachel A. King

Scripps Senior Theses

Invasive species are an increasingly severe conservation problem that can dramatically alter native plant communities. Although ecologists have proposed many mechanisms for the dominance of invasive species, superior competitive ability is one of the longest standing hypotheses. In winter annual plant communities, germination timing affects competition among plants. I hypothesized that grass invasion has changed the costs and benefits of early and late germination, and that species with flexible germination timing would compete better with invasives. Experiments at the Bernard Field Station in Claremont, CA and germinator trials in a controlled environment were used to examine the survivorship and germination …

Paleobiological Assessment Of Controls Underlying Long-Term Diversity Dynamics, Andrés L. Cárdenas

USF Tampa Graduate Theses and Dissertations

Deciphering the factors underlying both long-term patterns of diversity and taxonomic turnover rates (i.e., extinction, and origination) has been one of Paleobiology's major foci for the past three decades. The importance of documenting these components is that they will expand our ability to interpret and model the evolutionary processes underlying those trends, highlight the evolutionary impact of historical events, and contribute to the formulation of robust predictions about the future of global diversity in response to the current anthropologically driven environmental changes. Accordingly, the first part of this study examines the possible occurrence of global marine evolutionary environmental controls into …

Effects Of A Cymothoid Ectoparasite On The Turning Behavior (Lateralization) Of The Bridled Monocle Bream Scolopsis Bilineata, Laura Strong

Independent Study Project (ISP) Collection

Lateralization, or behavioral asymmetry, is the tendency to favor one side of the body over the other, and exists in humans and animals including in mammals, birds, and fishes. It has been found to increase performance in certain behaviors such as escape from predators by lowering reation time. Lateralization has predominantly genetic bases, but can also be influenced by environmental factors. For example, lateralization has been observed to increase in populations of fish subject to high predation pressure as it decreases their response time to predatory attacks. Parasitism may also have important effects on lateralization. In particular, increased drag from …

Paleoecological Study Of Unguja: Can Past Environments Be Inferred From Fossilized Corals And Mollusks?, Meredith Burger, Jory Lerback

Independent Study Project (ISP) Collection

A study was conducted on Unguja, an island off the eastern coast of Tanzania, to provide an overview of the paleoecology found in the cliff shelves across the island. It is known that Zanzibar was a submerged reef from the Neogene, approximately 23 million years ago (Ma). Two tests were carried out in 16 sites around the island. One test looked at coral fossils, while the other studied fossilized shells. Both tests measured biodiversity, with one specifically studying patterns of ocean currents, and the other studying nutrient levels and deposition rates. Biodiversity tests were inconclusive but coral diversity showed a …

From A Rodent To A Rhetorician: An Ideological Analysis Of George Alexander Kennedy's Comparative Rhetoric, James Begley

Masters Theses

George Alexander Kennedy, a professor of classics at the University of North Carolina at Chapel Hill, has given birth to a new understanding of rhetorical studies: he argues for the evolution of rhetoric from animals to humans. Using Sonja Foss's methodology of "ideological criticism," this thesis examined Kennedy's case as presented in his book, Comparative Rhetoric: an Historical and Cross-Cultural Introduction. This study discovered that the book was heavily influenced by a secular, pro-evolutionary ideology which dually contributed to its selective use of scientific evidences and production of inconsistent arguments. Evaluated on the basis of Biblical principles, this thesis concluded …

Reproduction And Population Characteristics Of White-Tailed Jackrabbits In South Dakota, Charles Dieter, Dustin Schaible

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

We evaluated the reproductive biology of314 white-tailed jackrabbits (Lepus townsendii) in 44 counties throughout South Dakota from June 2004 to September 2005. We classified jackrabbits as juveniles or adults based on the closure of the proximal epiphysis of the humerus using X-ray analysis. We determined annual reproductive activity through fluctuations in measured weights of reproductive organs for both sexes. The 2005 breeding season started in late February and proceeded until mid-July, approximately 142 days, allowing for females to potentially produce 3.3 litters. We found four distinct breeding periods by the overlap of estimated conception and parturition dates. Mean …

Channel Width And Least Tern And Piping Plover Nesting Incidence On The Lower Platte River, Nebraska, Joel G. Jorgensen, Mary Bomberger Brown, Andrew J. Tyre

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Endangered interior least terns (Sternula antillarum athalassos) and threatened northern Great Plains piping plovers (Charadrius melodus) nest together on midstream sandbars in large rivers in the interior of North America. We investigated the relationship between river channel width and tern and plover nesting incidence on the lower Platte River, Nebraska, using a model-based logistic regression analysis. Multiple channel width measurements and a long-term nesting data set were used in the analysis. Nesting incidence was positively associated with increasing river channel width proximal to the nesting site. At a greater distance, up to 802 m away from …

Effect Of Light Level On Feeding Behavior In A Lemur Species (Eulemur Rubriventer) With A Color Vision Polymorphism., Ainsley Lockhart

Independent Study Project (ISP) Collection

Understanding the visual capabilities and correlated behavior of prosimians provides vital information regarding the evolution of color vision. Feeding behavior in particular is often modified based on color vision status in various primate taxa. The present study examined feeding behavior under various light conditions in Eulemur rubriventer, a lemur species with a color vision polymorphism in which only females can have trichromatic vision. Behavioral observations were conducted for a single E. rubrventer group over a 13 day study period in April 2012. Results found no significant difference in rates of frugivory or exploitation of green vs. non-green food between male …

Coarse Woody Debris In A Tropical Rainforest In North Queensland, Australia: Relationships With Stand Structure And Disturbance, Nadine Rea

Independent Study Project (ISP) Collection

Coarse woody debris (CWD) refers to the woody material on the forest floor, including fallen stems, large branches, coarse roots, wood pieces, and standing dead trees (snags) (Harmon et al. 1986). CWD is an essential but often overlooked aspect of ecosystems. It plays many key ecosystem roles and is instrumental in overall ecosystem functionality. While a piece of CWD decomposes, it provides key habitat for many different species, minimizes soil erosion, affects soil development, stores nutrients and water, and influences the global carbon cycle (Harmon and Hua 1991). In some forests, CWD can exist on the forest floor for hundreds …

Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii

Biological Sciences Theses & Dissertations

The blue crab Callinectes sapidus occurs along the Atlantic and Gulf coasts of the United States, and in high salinity regions, they are subject to lethal infection by the parasitic dinoflagellate Hematodinium. In Virginia's seaside estuaries, the prevalence of Hematodinium infection of C. sapidus can sometimes exceed 50%, threatening the commercial fishery for this species. Indeed, other commercially important crustacean fisheries have approached collapse due to Hematodinium infections. Most studies of this host-parasite interaction have focused on epidemiology, host-pathogen dynamics, and pathogen transmission, and little is known about the impact of the parasite on host behavior and population dynamics. …