Life Sciences Commons^™

Ciliates Of Sagebrush-Steppe Soils Of Southwestern Idaho: Species Richness And Its Relationship To Changed Soil Variables After Wildfire Events, Laura G. Wendell

Boise State University Theses and Dissertations

I conducted a pilot study to examine species richness of terrestrial ciliates associated with big sagebrush habitat (Artemisia tridentata) in southwestern Idaho, USA. As wildland fires are a naturally occurring disturbance in this area, soil variables associated with these fires (% C, % N, pH, soil texture, and % clay) were measured at three sites, both in burned and unburned areas. These soil characteristics were compared to corresponding ciliate diversity and ratios of r-selected colpodeans to K-selected polyhymenophorans (C/P) in non-flooded Petri dish preparations. A total of 85 ciliate taxa were observed across the three sites, including …

Population Genetics, Distributions And Phenology Of Bombus Latreille, 1802 And Xylocopa Latreille, 1802 (Hymenoptera: Apidae), Amber Dawn Tripodi

Graduate Theses and Dissertations

This work addresses multiple knowledge gaps in bee ecology, population health and phylogeography in order to provide insights into the changing distributions of native bees. A comparison of Arkansas bumble bee records mirrors range-wide surveys, with records of stable species (Bombus bimaculatus Cresson, 1863 and B. impatiens Cresson, 1863) increasing three-fold, and records of the declining B. pensylvanicus (DeGeer, 1773) dropping to 60% of historical levels. However, nationally-recommended conservation-genetics tools did not mirror these results on a regional level. Stable and declining species had equivalent genetic diversity in samples from Arkansas and Tennessee (H_S range: 0.46-0.63). Diploid males, …

Turning Up The Heat On The Little Things That Run The World: Evaluating The Impacts Of Climate Change On Ant Biodiversity In The Temperate Forest Communities Of The Northeastern United States, Israel Del Toro

Doctoral Dissertations

Climatic change threatens biodiversity worldwide. In the forests of the northeastern United States, climate change is expected to increase mean annual temperatures by up to 4.5˚C and change precipitation seasonality. These changes in climate are likely to have impacts on the biodiversity of the region. In order to better understand the impacts of climate change on biodiversity, I used ants, an indicator taxonomic group, to predict how ant communities and ant-mediated ecosystem processes change as the climate warms. In the first chapter of this dissertation, I review the major ecosystem processes and services mediated by ants using the Millennium Ecosystem …

Influences Of Yard Management Intensity On Urban Soil Biogeochemistry, Viviana Penuela Useche

USF Tampa Graduate Theses and Dissertations

Soils are critical to ecosystem function as they provide essential nutrients for primary producers, habitat and organic energy for decomposers, and storage of organic matter. Irrigation with reclaimed water is an increasingly popular water conservation strategy; yet its high salinity and nutrient content potentially affect soil properties. In this study, set in a residential neighborhood of Tampa (U.S.). I tested whether there are distinct lawn system management strategies characterized by systematic differences in reclaimed water usage and irrigation and fertilization practices. I then investigated whether soil biogeochemistry responds to lawn system management strategy.

My results indicated that amendment strategy, which …

Facing The Wreck: Death, Optimism, And The Fragmented Form, Rachael Marie Schaffner

Graduate Theses and Dissertations

Walter Benjamin described history as a winged angel who faces backwards, staring perpetually into the past as the violent winds of destiny carry him into the future (Illuminations). Despite a western, post-enlightenment myth of eternal progress, the wreckage of human contributions to history is clearly evident in our 21st-century understanding of anthropogenic impact on global ecology. In the context of these ecological crises (and the resulting political and economic questions), postmodern novels reveal a powerful ability to imagine different ways of living and interacting with the world. This thesis traces the relationship between fragmentation, death, and liminal experiences …

Comparing Population Density Estimation Techniques For Columbia Black-Tailed Deer (Odocoileus Hemionus Columbianus): Fecal Standing Crop And Distance Sampling Methods, Jubilee D. Brenneman

Honors Projects

I estimated deer density and population size on Blakely Island, WA, using the fecal standing crop (FSC) method described by Martin et al. (2011). I compared the FSC method with a well established and broadly applicable estimation method, distance sampling. Additionally, architecture of a commonly browsed shrub, Ocean Spray (Holodiscus discolor), was measured as an indicator of browsing pressure. Fecal standing crop was estimated by counting pellet groups along 26, 100 x 2m line transects. Deer density was estimated using these data and the equation derived by Martin et al. (2011). Distance sampling consisted of recording perpendicular distance …

Turtle Town: Creating A Self-Sustainable Ecosystem Using An Ecological Approach To Turtle Aquarium Design, Sheena K. O'Donnell

Undergraduate University Honors Capstones

Typical pet turtle tank setups do not utilize the complete nutrient cycle seen in a functional natural ecosystem. This dysfunction results in waste and nutrient buildup, which is currently managed by water changes and regular tank cleaning. This type of maintenance can be costly and time-consuming -- not to mention unpleasant and hazardous to the aquarium owner's health. This study tested the effectiveness of using plants as part of a proposed ecological tank design to minimize waste buildup by utilizing nutrients. Wastewater from a dirty turtle tank was transferred to a tank setup containing three plants (Experimental Batch 1), while …

Range Collapse, Genetic Differentiation, And Climate Change: An Ecological History Of The Diana Fritillary, Speyeria Diana And Projections For Its Future, Carrie Wells

All Dissertations

The geographic ranges of most plant and animal species are tied closely to climatic factors, including temperature, precipitation, and soil moisture. For this reason, recent changes in the global climate due to human activities are predicted to have profound effects on natural populations, communities and ecosystems over a relatively short period of time. Combined effects from global warming and other anthropogenic activities such as land-use changes, pollution, and habitat loss/fragmentation, are altering species' distributions faster than they can be documented. Recent climate change has also been shown to alter species' breeding behaviors and alter the synchrony and timing of species' …

Foraging Ecology Of Cougars In The Pryor Mountains Of Wyoming And Montana, Linsey Blake

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We conducted this study to better understand the impact of cougar (Puma concolor) predation in the Pryor Mountains of Wyoming and Montana. Managers of the Bighorn Canyon National Recreation Area and the Pryor Mountain Wild Horse Range were concerned that cougars were having a negative impact upon a small, isolated Rocky Mountain bighorn sheep (Ovis canadensis canadensis) population and were hoping predation might be limiting a feral horse population (Equus caballus) that was in excess of the Appropriate Management Level set by the Bureau of Land Management. Wildlife tourism brings revenue to the park …

Synthesizing Research And Education: Ecology And Genetics Of Independent Fern Gametophytes And Teaching Science Inquiry And Content Through Simulations, Aaron M. Duffy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mission statements of Utah State University and the Department of Biology, as well as the requirements of funding agencies like the National Science Foundation encourage an integration of teaching and research. I have attempted to achieve that in my dissertation work by using tools I originally created to support and inform my biological research projects to teach science content and inquiry to middle school and undergraduate students.

Chapter 2 of this dissertation reports the results of surveys for Hymenophyllum wrightii, a fern with independent gametophyte populations in the Pacific Northwest, which improved our understanding of the range, distribution, …

Spatial And Habitat Responses Of Canada Lynx In Maine To A Decline In Snowshoe Hare Density, David G. Mallett

Electronic Theses and Dissertations

Previous studies of Canada lynx (Lynx canadensis) within the northern boreal forest region have documented that lynx respond spatially to a decline in snowshoe hare (Lepus americanus) density, as exhibited by expansion of territories and changes in social structure. I compared home range area and spatial overlap in the southeastern portion of their geographic range during periods of relatively high and relatively low hare density. Home range areas of lynx did not change between periods of high and low hare density, except that home ranges of females during the denning season expanded during the low period. The presence of kittens …

Investigating The Impact Of Novel Iron Oxide Nanoparticles On Legionella Pneumophila Biofilms And Trophic Interactions, Brennen Jenkins

All Theses

Microbial biofilms serve as the base of food webs and are important for nutrient cycling in aquatic ecosystems. Nanoparticles (NPs) that enter into these aquatic systems have the potential to settle and become trapped within biofilms. As NPs become further integrated into consumer products, understanding their fate and effects on aquatic ecosystems is of paramount importance. Previous studies from our lab show that gold NPs induce dispersal of Legionella pneumophila biofilms. NPs with platinum and iron oxide core chemistries also lead to similar dispersal events, however, silver core NPs do not seem to induce these events due to NP aggregation. …

Naturalized Offspring From An 85-Year-Old Chinese Chestnut (Castanea Mollissima) Planting: Stand Dynamics And Genetic Relationships, Amy Christel Miller

Open Access Theses

Chestnuts, members of the genus Castanea , family Fagaceae, are valuable worldwide, and all species have noteworthy ecological, economic, and cultural importance in their native ranges. Historically, American chestnut (Castanea dentata (Marshall) Borkh.) was an abundant tree species in eastern North America until its decimation in the early 20 th century by chestnut blight, caused by the fungus Cryphonectria parasitica . To regain the benefits of this prized species in North America, efforts are ongoing to produce and introduce blight-resistant hybrids of C. dentata and the blight-resistant Chinese chestnut ( C. mollissima Blume). It is important that the C. …

Overwintering And Early Season Amplification Of Eastern Equine Encephalitis Virus In The Southeastern United States, Andrea Bingham

USF Tampa Graduate Theses and Dissertations

Eastern equine encephalitis virus (EEEV) is a highly pathogenic arbovirus that causes severe disease, with a mortality rate of approximately 30-35% in humans and 80-90% in horses. Studies dating back to the 1930's have identified many of the epidemiological and ecological aspects of the virus. However, there are several aspects of EEEV's transmission cycle that remain unclear. In the northeastern states, transmission is seasonal, peaking in the late summer months, while in Florida there is year-round transmission of EEEV. Recent phylogenetic studies have also suggested that Florida may serve as a reservoir for EEEV; the virus may periodically be introduced …

A Genealogy Of Ecological Rhetoric: Heraclitus, Bacon, Darwin And Huxley, Jared Grogan

Wayne State University Dissertations

This dissertation is a genealogical study of historical intersections between rhetoric and ecology. Studying the works of Heraclitus, Francis Bacon, T.H. Huxley and Darwin as "bridge figures" in the history of rhetoric, science and ecological thought, I examine how their rhetorical theories and strategies (as discursive practices, performances and techniques) form a genealogy that bridges rhetorical and ecological theories and practices. My analysis studies their critical assessments and uses of rhetoric as it intersects with each figure's new investigations into natural philosophy, nature, and evolutionary biology, while drawing out relevant lessons for contemporary ecological and rhetorical thinkers. The main threads …

Natural History Of A Population Of Wood Turtles (Glyptemys Insculpta) In West Virginia, Jessica Curtis

Theses, Dissertations and Capstones

The Wood Turtle (Glyptemys insculpta) is listed as vulnerable in West Virginia and only occurs in the Eastern Panhandle. The study population is unique in West Virginia because it occurs at a much higher mean elevation than other Wood Turtle populations in the state. The primary objective of this study was to determine if, and to what extent, altitude affected this population’s ecology. Turtles were located with opportunistic surveys and captured by hand. I located 31 turtles: 18 males, and 13 females. Turtles were captured a total of 68 times. Ratio of males to females did not differ significantly from …

The Natural Life History Of Cambarus (Puncticambarus) Smilax, The Greenbrier Crayfish, Paul William Hughes

Theses, Dissertations and Capstones

The natural life history of Cambarus (Puncticambarus) smilax, the Greenbrier Crayfish, was studied in West Fork of the Greenbrier River and in Thorny Creek, a tributary of the main stem of the Greenbrier River. The Greenbrier Crayfish gets its name from the Greenbrier River watershed where it is thought to occur exclusively. Among described members of the subgenus Puncticambarus, C. smilax is a sister taxon most similar to Cambarus (Puncticambarus) robustus. Monthly collections were made within the two study sites, from August 2010 to July 2011. Collecting techniques included dip-netting, seine-netting, and hand collecting. Cambarus smilax and all other species …

Methodological Advancements For Improving Performance And Generating Ensemble Ecological Niche Models, Robert Boria

Dissertations and Theses

This study employs spatial filtering of occurrence data with the aim of reducing overfitting to sampling bias in ecological niche models (ENMs). Sampling bias in geographic space leads to localities that may also be biased in environmental space. If so, the model can overfit to those biases. As a preliminary test addressing this issue, we used Maxent, bioclimatic variables, and occurrence localities of a broadly distributed Malagasy tenrec, Microgale cowani (Family Tenrecidae: Subfamily Oryzorictinae). We modeled the abiotically suitable area of this species using three distinct datasets: unfiltered, spatially filtered, and rarefied unfiltered localities. To quantify overfitting and model performance, …

Effects Of Mechanical Habitat Disturbance On The Diversity And Network Structure Of Plant-Bee Interaction Networks In Central Florida, Karlie Carman

Electronic Theses and Dissertations

Ecological interactions within a community shape the structure of ecosystems and influence ecosystem function. Plant-pollinator interactions exist as mutualistic exchange networks that may collapse as habitat loss occurs, thereby threatening the overall health of an ecosystem. Understanding the impacts of human-mediated habitat disturbance on ecological interactions is therefore crucial for conservation efforts. Archbold Biological Station (ABS) in Venus, Florida contains over 2000 hectares of protected Florida scrub habitat nested within a human-dominated environment that is threatened by anthropogenic habitat disturbance. In past studies, over 113 bee species and 157 associated host plants, many endemic to the Lake Wales Ridge, have …

Evaluation Of The Three-Dimensional Patterns And Ecological Impacts Of The Invasive Old World Climbing Fern (Lygodium Microphyllum), Alexis Maldonado

Electronic Theses and Dissertations

Invasion by non-native species has had significant ecological and economic impacts on a global scale. In the state of Florida, Old World climbing fern (Lygodium microphyllum) is an invasive plant listed by FLEPPC as a category one invader with significant ecological impacts that threaten native plant diversity. This species relies on existing vegetative structures for support to climb into the forest canopy and forms dense mats that cover tree crowns. This subsequently affects the resources available to other species present. Quantifying the structural changes due to the presence of this species has proved logistically difficult, especially on a large spatial …