Biology Commons^™

Residency, Diel Movement, And Tidal Patterns Of Large Juvenile Bull Sharks (Carcharhinus Leucas) In Winyah Bay, Sc, Jeremy Lee Arnt

Electronic Theses and Dissertations

No abstract provided.

Carbon Sequestration In A Restored West Michigan Oak Savanna: Implications For Management Practices, Jeffrey A. Heise

Masters Theses

The savanna system is an ecosystem (i.e. a transitional ecosystem) that lies between forest and grassland ecosystems. They occur across the world in various forms, but in the North American Midwest they are specifically oak savannas: systems where the open overstory is dominated by various species of oak (Quercus spp.) and the understory consists of carbon-rich prairie grasses and forbs. This ecosystem is a highly degraded ecosystem and has lost almost 99% of its former range due to agriculture and fire suppression. Since savannas are fire-evolved systems, they are maintained by and require fire as a regular disturbance to …

The Evolution Of Life Histories And Phenotypic Plasticity Across Environmental Gradients In Daphnia Sp., Michelle Renee Swan Packer

Biology Dissertations

Understanding how environmentally-induced variation ultimately leads to speciation is a main component of evolutionary ecology. This dissertation uses Daphnia in experimental and comparative studies to address several theoretical questions concerning the role of phenotypic plasticity in the evolutionary process. Specifically, I explore novel environmental factors which induce plasticity and investigate the plastic response across systems to determine general hypotheses for understanding the mechanisms which may be involved. Additionally, this dissertation provides empirical results which add to the body of research investigating the transition between environmentally induced phenotypes and genetic adaptation. The results of this body of work show that ancestral …

Analyzing Thermal Gradients Using Terrestrial Laser Scanning In Scrub Oak Habitats, Alyssa Silbey

Honors Theses

Thermal microclimates are an important component of natural ecosystems because they provide appropriate niche space for many organisms; however, they are not widely studied because of their small scale. Likewise, variation in these microclimates may significantly impact animal thermoregulation and plant physiological processes and be especially important in the face of climate change. The goal of this study is to determine how the size and structure of Quercus ilicifolia shrubs influences ground temperature gradients. We hypothesized that differences in leaf cover and leaf area index (LAI) would cause temperature under shrubs to cool relative to the ambient temperature, and that …

Ecological Analyses Of Macroinvertebrates And Fish Species In Six Streams On A Louisiana Military Base From 2001 To 2019, Danielle Joerger

Biology Theses

An in-depth ecological analysis of how and why the aquatic community changes over time was conducted for 6 streams on the Fort Polk military base in Louisiana using data collected from 2001 to 2019. Fort Polk is a unique location as nineteen first-order streams are located on the premises belonging to three separate drainages. The primary goal was to determine whether temporal or between-drainage variation has a larger effect on community structure. To accomplish this the effects of disturbance on fish and macroinvertebrate assemblages was determined temporally and between drainages. Several hypotheses were drawn from this: 1) temporally, assemblages exhibit …

Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey

Master's Theses

Aedes aegypti, the primary mosquito vector of the yellow fever virus, threatens global health by passing on this virus, as well as chikungunya, dengue, and Zika viruses. Through its natural tendency to live in highly urban areas and bite human hosts; understanding the factors that affect the historical and current range of the pest is invaluable (Gubler, 1998). Although these viruses are not normally found in the United States, lack of vaccinations and wide-spread presence of the mosquito could lead to these diseases being reintroduced with potentially devastating effects (Monath, 2001). To determine a partial historical range of A. aegypti …

Chronoecology Of A Cave-Dwelling Orb-Weaver Spider, Meta Ovalis (Araneae: Tetragnathidae), Rebecca Steele

Electronic Theses and Dissertations

Circadian clocks enable coordination of essential biological and metabolic processes in relation to the 24-hour light cycle. However, there are many habitats that are not subject to this light cycle, such as the deep sea, arctic regions, and cave systems. This study analyzes the circadian pattern of isolated populations of a subterranean spider, Meta ovalis from two Tennessee caves and five Indiana caves. Locomotor activity was recorded with TriKinetics LAM50 Locomotor Activity Monitor under a 12-hour light (L), 12-hour dark (D) (LD 12:12) cycle preceding total darkness (DD). Significant differences were found within and among populations found in Tennessee cave …

Ground Beetle (Coleoptera: Carabidae) Assemblages In Native, Invasive, And Encroaching Grassland Habitats, Madison Pittenger

Master's Theses

Ground beetles (Carabidae) are increasingly used as ecological indicators in studies regarding land use because they are ubiquitous, respond quickly to environmental change, have a well-understood taxonomy, and can be trapped with ease. While the effects of various plant communities on ground beetle assemblages are relatively well-known, past studies have operated within boreal and tropical forests and have not placed much emphasis on the effects of native and nonnative species. In this study, ground beetles were investigated as indicators of invasion in a grassland setting. Ground beetles were sampled using pitfall traps throughout the 2018 growing season at Quivira National …

Effects Of Forest Age And Composition On Coleoptera Associated With Fungal Fruiting Bodies In Southwest Ohio, Jeffrey M. Brown

Browse all Theses and Dissertations

Mature forests often harbor greater biodiversity than younger woods. As this relationship of forest age to biodiversity has not been examined for all taxa, this study sought to document the diversity of mycophilous beetle communities in deciduous forests of southwest Ohio and understand how they vary in relation to forest age. I surveyed fungus associated beetles using baited traps at eight forested sites in the Dayton, Ohio region. Traps were surveyed three times during 2018 to account for seasonal variation, something that has not been done for this geographic region. Forest age had no significant effect on beetle abundance or …

Influence Of Light Availability On Tree Growth, Defense, And Emerald Ash Borer (Agrlius Planipennis) Success In White Fringetree (Chionanthus Virginicus) And Black Ash (Fraxinus Nigra), Michael S. Friedman

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White fringetree is a host for the invasive emerald ash borer (EAB) despite being lower quality than black ash. Observations suggest that host trees grown in full sun are more resistant to EAB than those grown in shade, however chemical defense mechanisms and the impact of environmental stress have not been assessed. We quantified constitutive and induced defenses and other characteristics white fringetree and black ash phloem tissue grown under differential light conditions, and these traits were related to EAB larval performance. White fringetree had significantly lower constitutive and induced activities of defense associated enzymes and lignin but higher phenolic, …

Brown Booby Family Units: Comparing Mothers, Fathers, And Chicks Through Stable Isotopes, Erin Taylor

Williams Honors College, Honors Research Projects

Seabird behavior and diet is important to study in order to determine where to focus conservation efforts in a rapidly changing climate. A primary aim of my project is to understand how brown booby family members from a breeding colony on Islas Marietas, Mexico relate to each other isotopically and in terms of their diet. Comparing the family units (mother, father, and chick from the same nest) of these seabirds and sex trends overall will help develop the big picture to determine the best conservation efforts for this species. I also aim to improve our ability to compare seabird plasma …

Fate Of White Fringetree Through The Invasion Wave Of Emerald Ash Borer And Its Variation In Resistance To Attack, Emily A. Ellison

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Ornamental white fringetrees in IL, IN, OH, and PA were reassessed in 2018 as a follow-up study to determine the fate of the white fringetree through the invasion wave of emerald ash borer. Attack rates decline by half from 2015-2018 and only 13% of trees were infested. Health of not reinfested trees in 2018 improved suggesting resilience against EAB attack whereas currently infested trees in 2018 displayed signs of declining health. Trees differed in their resistance to EAB attack and 41 additional ornamental and wild white fringetrees were studied in OH to determine if the anti-herbivory defense chemical, oleuropein, influenced …

Invasive Species Shift Fungal Driven Decomposition In Midwestern Forests, Adam M. Reed

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Midwestern forests are currently impacted by two prominent invaders, Agrilus planipennis and Lonicera maackii. The Ag. planipennis induced loss of Fraxinus spp. trees can facilitate Lo. maackii invasion, which is likely altering microbial driven forest nutrient cycling. To assess these changes in microbial processes, I conducted litter bag and culture-based decomposition experiments using leaf litter from Acer spp., Quercus spp., F. nigra, F. pennsylvanica, Lindera benzoin, and Lo. maackii. For the culture-based decomposition experiment, I inoculated six species of fungi separately onto both single species and multispecies (half Lo. maackii and half native spp.) leaf litter and measured decomposition rate, …

Composition Of Dung Beetle Communities In A Tropical Montane Forest Alters The Rate Of Dung Removal More Than Species Diversity Alone, Elizabeth A. Engle

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Dung beetles provide key ecological functions by degrading and recycling dung. I used experimentally-assembled communities to examine the role of species richness, community biomass, species diversity, species identity, and community composition in dung removal, using Ateuchus chrysopyge, Copris nubilosis, Onothophagus cyanellus, and Dichotomius satanas. I hypothesized: (1) that as species richness, biomass, and diversity increases within a community, dung removal increases; and (2) species are not functionally equivalent, so community composition should influence dung removal rates. As species richness, biomass, and diversity of experimentally-assembled communities increased, the proportion of dung removed also increased. Also, the four species in this study …

The Influence Of Landscape Factors On Black-Tailed Prairie Dog (Cynomys Ludovicianus) Colony Persistence In Northwest Kansas, Jamie Oriez

Master's Theses

The black-tailed prairie dog (Cynomys ludovicianus) is a colonial and fossorial rodent species that serves as an ecosystem engineer and keystone species in North America’s grasslands. Black-tailed prairie dogs historically ranged from northern Mexico to southern Canada, and from eastern Nebraska to the foothills of the Rocky Mountains. However, with the loss and fragmentation of grasslands, introduction of Sylvatic plague (Yersinia pestis), and control measures such as poisoning and shooting, black-tailed prairie dogs are limited to less than 5 percent of their historical range.

In this study, I examined how colony area, location, isolation, and surrounding …

The Effects Of Low-Level Pharmaceuticals On Stream Biofilm Structure And Function Across A Land-Use Gradient In Streams Of The Huron River Watershed, Elizabeth Mae Stover

Master's Theses and Doctoral Dissertations

Pharmaceuticals and personal care products (PPCPs) are a contaminant class of worldwide concern. Their environmental omnipresence indicates they may be a potential source of global change, and ecosystem-scale impacts at non-lethal levels have not been fully explored. We used stream biofilms to assess ecosystem responses to PPCPs. Biofilms were cultivated in streams draining areas of different land use and then exposed to triclosan, diphenhydramine, and sulfamethoxazole-trimethoprim treatments. We found evidence that low levels of these PPCPs affected some, but not all, aspects of biofilm processes and bacterial community composition. Bacterial carbon uptake was reduced (p = 0.06) and we found …

Community Structure Of Benthic Microbial Mats At Hydrothermal Springs In Crater Lake, Oregon, Amanda Stromecki

WWU Graduate School Collection

Crater Lake, Oregon is an oligotrophic freshwater caldera lake fed by thermally and chemically-enriched hydrothermal springs. These vents distinguish Crater Lake from other freshwater systems and provide a unique ecosystem for study. This study examines the microbial community structure of hydrothermal mat communities found in the bottom of Crater Lake. Small subunit rRNA gene amplicon sequencing from eight microbial mats was used to assess community structure. These findings revealed a relatively homogeneous, yet diverse bacterial community. High alpha diversity and low beta diversity indicates that these communities are likely fueled by homogeneous and consistent hydrothermal fluids. An examination of autotrophic …