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Microplastics In Wetlands Of West Central Ohio : Concentration And Distribution, Mitchell Link

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Wetlands provide many valuable ecosystem services; however, an emerging global contaminant—microplastic (< 5 mm)—may be degrading this important resource. Few studies have extensively surveyed microplastic distribution in wetlands over a broad spatial area. Therefore, the goal of this study is to identify where microplastics are accumulating in wetlands, and whether there is any correlation between microplastic concentration and wetland quality. Soil samples were collected from 30 wetlands in west–central Ohio. Samples were physically separated, density separated, and digested. Average microplastic concentrations were 637 ± 494 items per kg soil per wetland. Higher quality wetlands are accumulating larger concentrations of microplastics. This relationship seems to be driven by greater accumulation of microplastics in forested wetlands than in wetlands surrounded by agriculture. There is no clear distribution pattern of microplastics within wetlands. These results provide insight into the role that wetlands have in association with microplastic accumulation.

To What Extent Do Non-Native Shrubs Support Higher Trophic Levels?, Ari Zakroff

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Invasive species threaten ecosystems and economies. Globally, biological invasions are estimated to have cost over $2.1 trillion since 1970. In Eastern North American woodlands, invasive plants are rapidly displacing natives. This is concerning, because invasive plants may not support the diverse and abundant arthropod communities essential to ecosystem function. Despite the conceptual understanding of invasive shrubs’ potential to transform forest communities, scant research has focused on the effect of invasive plants on higher trophic levels here in Ohio. To address this gap, I examined the diversity and abundance of arthropod communities, caterpillar performance, and caterpillar predation on two invasive shrubs, …

Exploring The Host Range, Impacts, And Distribution Of Black Rot Disease On Alliaria Petiolata, Gabriela Ivette Harney-Davila

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Garlic mustard is an invasive Eurasian biennial spreading in deciduous forests of North America. Garlic mustard plants in Ohio can be infected with a strain of Xanthomonas campestris, the causal agent of black rot disease in brassicas. I examined variation in susceptibility to X. campestris among garlic mustard populations, several native wild species, and agricultural crop varieties. Twenty-four garlic mustard populations were universally susceptible to X. campestris, though disease severity varied. Cardamine concatenata and Cardamine diphylla were susceptible but can phenologically escape infection in the field. Of the 14 agricultural crops tested, three cultivars (Raphanus sativus, Brassica rapa var. Rapa …

Evaluating Energy-Based Trait Shifts And Population Level Impacts Of Big Brown Bats (Eptesicus Fuscus) With Long-Term Exposure To Pseudogymnoascus Destructans, Molly C. Simonis

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Disturbances in environment can lead to a wide range of host physiological responses. These responses can either allow hosts to adjust to new conditions in their environment or can reduce their survival, and can subsequently cause host traits to shift. Small mammals are particularly vulnerable to stochastic disturbances, like a pathogen introduction, because of their high energy demands. Studies examining host responses to pathogens often focus on species highly susceptible to infection that typically have high mortality rates, leading to a gap in understanding the responses of less susceptible species. My dissertation evaluates the energy balance of Eptesicus fuscus (big …

Analyses Of Coyote (Canis Latrans) Consumption Of Anthropogenic Material And Dietary Composition In Urban And Non-Urban Habitats, Audrey A. Hayes

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Coyotes are a generalist species that have adapted to nearly every terrestrial habitat in the United States. The species’ success is heavily attributed to their omnivorous diets and tolerance for environments that are regularly disturbed. Because the larger predator species that typically act as apex predators are sensitive to highly fragmented landscapes, the coyote is the functioning apex predator in many ecosystems where large predators, such as wolves, have been extirpated. The coyotes’ ecological role in urban ecosystems has received much attention in the last few decades as the species’ presence in cities and suburbs has increased, along with human-coyote …

Analysis Of Amur Honeysuckle Stem Density As A Function Of Spatial Clustering, Horizontal Distance From Streams, Trails, And Elevation In Riparian Forests, Greene County, Ohio, Greg Michael Grierson Jr.

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The non-native invasive shrub Amur honeysuckle, Lonicera maackii (Rupr.) Herder (Gorchov and Trisel, 2003), is one of the most prolific invasive plant species across Midwestern and Northeastern landscapes of the United States. The locations of 2,095 individual Amur honeysuckle stems were geolocated using handheld GPS units in the understory of mixed growth forests at two study sites located approximately 5 km apart in northwestern Greene County, OH. Each site has undergone different levels of anthropogenic disturbance through time. The stem position data was used to measure the spatial clumping distribution and the density of Amur honeysuckle. The spatial clumping of …

Diversity And Function Of Algal Biofilms In The Laurentian Great Lakes, Leon R. Katona

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Attached algae are ubiquitous components of lake benthic habitats wherever sufficient light reaches submerged surfaces. Attached algae interact with heterotrophic bacteria and fungi to form complex biofilms (“periphyton”) that provide a nutritious food source for consumers and influence biogeochemical cycling by regulating redox potential at the sediment-water interface. Despite their ecological importance, there are limited data on the role of periphyton in the Laurentian Great Lakes. I quantified wave exposure and light availability in rocky nearshore habitats in Lake Erie and Lake Huron. Periphyton biomass and productivity in nearshore Lake Erie was very high while algal biomass and productivity in …

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, …

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 …

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

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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 …

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 …

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, …

Genetic Analysis Of Snow Leopard Population Employing Next Generation Sequencing For Its Improved Conservation And Management, Safia Janjua

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Snow leopards (Panthera uncia) are an enigmatic, high-altitude species whose challenging habitat, low population densities and patchy distribution have presented challenges for scientists studying its biology, population structure, and genetics. To address these important ecological, conservation, and evolutionary questions, scientists are tailoring laboratory and computational methods to better extract the information from non-invasive samples, only available source of DNA for this species. These samples with very low quantity and quality of DNA, present unique methodological challenges. ddRAD-seq, one of next generation sequencing method is used here to develop reference sequence library for snow leopard using five blood samples from Mongolian …

Effects Of Coral Reef Habitat Complexity On The Community Composition And Trophic Structure Of Marine Fish Assemblages In Indonesia’S Wakatobi Marine National Park, Kuyer Josiah Fazekas Jr.

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The coral reefs within Indonesia’s Wakatobi Marine National Park support a high diversity of reef-building hard corals and associated marine fish. Climate change threatens to dramatically affect coral reef ecosystems by altering the interactions between reef fish and the specific microhabitats they depend on for survival. To examine the spatially varied effects of habitat complexity on the community composition and trophic structure of marine fish assemblages, I analyzed fish community and habitat complexity data across reef zones. Habitat complexity metrics were: structural complexity, the percentage of hard coral (HC) cover, HC genera richness, HC genera diversity (Shannon index), and HC …

Bat Species Diversity And Habitat Use Assessment With Focus On Endangered Indiana Bats In The Wright State University Woods, Megan R. Rude

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The goals of my thesis are to: 1) identify species of bats in Wright State University’s (WSU) campus woods via acoustic surveys to compare to detections from previous years (Chapter 1) (2) analyze occupancy and detection probabilities of Indiana bats in different areas throughout the woods (Chapter 1), and 3) create an acoustical approach to analyze habitat use through bat social calls (Chapter 2). In Chapter 1, I conducted stationary acoustic surveys in the Wright State University woods in hydric (riparian), edge, and old growth habitats to record bat vocalizations. The WSU woods have a diverse bat community as ten …

Vegetation Sensitivity During The Mid-Holocene Warming In Western Ohio, Kristin Kopera

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There has been a growing interest in prairie reconstruction in western Ohio, yet there are few recent academic sources supporting the claim that prairies appeared in western Ohio during the mid-Holocene. The hypsithermal was the warmest and driest part of the Holocene and occurred from 8,000-4,000 years ago in the Midwest. During the hypsithermal, the Prairie Peninsula appeared from Minnesota to eastern Ohio. If prairie did appear in Ohio, it occurred during the mid-Holocene hypsithermal. The goal of this study was to determine if western Ohio experienced a prairie period during the hypsithermal using pollen as a proxy for past …

Nutrient Flux From Aquatic To Terrestrial Invertebrate Communities Across A Lakeside Ecotone, Hosanna B. Loreaux

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In this study, I examined how the spatiotemporal distribution of spider webs and diet changed in a lake riparian zone with increasing distance from an aquatic resource. I surveyed twenty, one-hundred meter transects along the perimeters of Sanford and Escanaba lakes (Wisconsin). Overall, spider web abundance was highest near the lakes and decreased moving into the adjacent forest. Horizontal orb webs, vertical orb webs, and mesh webs showed strong negative relationships with distance from the lakes. Aquatic insects composed an average 36-64% of spider diet for all spider families throughout the riparian zone, suggesting that some spider families are selecting …

River Biofilm Structure And Function In A Resource Landscape Modified By Agriculture: Implications For Primary Consumers, Hannah M. Fazekas

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Anthropogenic alterations to nitrogen, carbon, and phosphorus bioavailability have increased the flux of these resources into the biosphere and altered stream ecosystem function. Streams modify the transport of these resources to receiving ecosystems through uptake, transformation, and mineralization. Understanding how streams process carbon, nitrogen, and phosphorus can provide insight about how stream ecosystems function in landscapes where human modification is inescapable. I investigated how land use in agricultural regions affect resource availability to primary producers and consumers and the subsequent impact on stream processes. I surveyed headwater streams in three Lake Erie watersheds to determine spatiotemporal nutrient limitation of attached …

Lonicera Maackii Alters Decay Dynamics Of Coarse Woody Debris, Michaela J. Woods

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Since industrialization, anthropogenic carbon emissions have led to excess atmospheric carbon dioxide that may alter the stability of ecosystem processes. Microorganisms are essential in mitigating excess carbon and play a notable role in the breakdown of organic material. This process, decomposition, is essential in forested ecosystems where microorganisms can recycle nutrients and store carbon in soil organic matter or release it through respiration. Fungi participate in decomposition through the release of enzymes responsible for carrying out the chemical reactions that break down plant material. Species introductions have the potential to alter decomposition dynamics. In the Midwestern US, the invasive shrub …

Comparing Created And Natural Depressional Wetlands Through Trophic Analysis Of Macroinvertebrates, Shante N. Eisele

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Macroinvertebrates are important contributors to wetland ecosystems due to their role in decomposition, nutrient cycling, and as a food resource for other organisms. Several studies have analyzed the macroinvertebrate communities in created wetlands, but few have evaluated them in the context of trophic structure in both created and natural wetlands. The objective of this study is to better understand benthic macroinvertebrate community composition and trophic structure in created and natural wetlands. My central hypotheses were that macroinvertebrate communities in created wetlands would have (1) differing composition and (2) less complex trophic structure with shorter food-chain length compared to natural wetlands. …

Monitoring Ohio Bat Communities And Populations Using Mobile Acoustics, Molly C. Simonis

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The goal of my thesis is to: 1) provide baseline information of where Ohio bats are foraging in Wright State University's (WSU) campus woods in relation to forest age and habitat (Chapter 1), 2) determine potential roost availability for local bats (Chapter 1), and 3) examine changes in state-wide species composition following the introduction of White-nose Syndrome (WNS; Chapter 2). In Chapter 1, I created walking bat acoustic routes and used generalized linear models to determine what forest ages and habitats had the greatest bat activity in the WSU campus woods. I conducted habitat transects throughout all forest ages to …

The Missing Metric: An Evaluation Of Microorganism Importance In Wetland Assessments, Aaron John Onufrak

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In the contiguous US, an estimated 50% of original wetland areas have been lost since the late 1700s. In growing recognition of the importance of preserving wetland ecosystem function, federal and state agencies have developed proxy-based functional-assessment procedures to manage and preserve remaining wetland areas. Ohio uses the Ohio Rapid Assessment Method (ORAM) to score wetland quality based on six metrics: wetland size, buffer width and surrounding land use, hydrology, habitat alteration and development, special wetland communities, and vegetation. Currently, the ORAM, and many other wetland scoring systems, do not consider microorganisms when determining wetland quality. This is particularly notable, …

Survey Of A Neotropical Anuran Assemblage (Pacaya-Samiria Reserve, Peru), Eric Woebbe

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The Pacaya-Samiria National Reserve of Peru is one of the largest protected areas of the Amazon rainforest, yet it has hosted only a few studies of frogs and toads (anurans). The primary goals of my study are: 1) To conduct an inventory of the local anuran species, 2) to quantify richness among habitats, 3) to compare differences in beta diversity across a river versus a continuous landscape, and 4) to compare difference in body size between nocturnal and diurnal individuals. After eight weeks of daytime and nighttime surveys during the dry season, a total of 601 individuals were identified across …

Determinants Of Host Use In Tachinid Parasitoids (Diptera: Tachinidae) Of Stink Bugs (Hemiptera: Pentatomidae) In Southwest Ohio, Matthew W. Duncan

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Tachinid parasitoids in the subfamily Phasiinae are important natural enemies of heteropteran bugs. Host location by these flies occurs via antennal reception to the pheromones of their hosts; however little is known regarding the mechanisms which underlie host selection. Halyomorpha halys, the invasive brown marmorated stink bug, represents a potential novel host species in North America. This study was conducted to determine the suitability of H. halys as a host for phasiine species, and to assess cues used in host selection by the species Gymnoclytia occidua. Field attraction to pentatomid pheromones by both phasiines and pentatomids in Southwest Ohio were …

Mechanisms Of Antixenosis And Antibiosis Of Ash Against Emerald Ash Borer, Chad Michael Rigsby

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Emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae), is an invasive forest pest causing widespread mortality of ash (Fraxinus spp.) in North America. Host resistance research and the development of resistant hosts offers a promising strategy for the long-term conservation of ash and management of EAB. Manchurian ash (F. mandshurica) shares an evolutionary history with EAB in Asia, resulting in its greater resistance relative to naive North American ashes. In the following studies I investigate antixenosis and antibiosis mechanisms of resistant and susceptible ashes. Antixenosis in Manchurian ash was demonstrated by quantifying substantially lower oviposition on this species relative to …

Evaluating Threats To The Rare Butterfly, Pieris Virginiensis, Samantha Lynn Davis

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Humans have caused drastic changes in ecosystems and communities through their modification of the natural landscape. Rare species, often highly specialized, are more impacted by these changes. Pieris virginiensis is a rare butterfly native to eastern North America that is a species of concern due to negative influences from habitat loss and plant invasion. This thesis discusses several threats to P. virginiensis, including habitat loss, climate change, competition, and the cascading effects of a novel European invasive plant, Alliaria petiolata, that attracts oviposition but does not allow for larval survival.

First, I examined a local extinction event and …

Likely Successors Of Ash Species In Response To The Emerald Ash Borer In Ohio Forests, Brian Michael Good

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Invasive species have the capability to alter landscapes and change the composition of a forest in a very short time. The recent invasive pest, Agrilus planipennis, emerald ash borer, was unintentionally introduced to the United States via ship route to Michigan. The pest attacks and kills all five native ash species in Ohio. This study focused on an area in west central Ohio not yet affected by the borer. Ash centered plots were used to record all species and sizes (diameter at breast height) within a 5m radius of a central ash tree. Plots ranged in topography and all five …

Soil Moisture, Fire, And Tree Community Structure, William Patrick White

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My study was conducted to understand tree community structure and how soil moisture and fire frequency influence them. Eighteen plots were placed in the Edge of Appalachia Nature Preserve of unglaciated southern Ohio: nine within a prescribed burn site and nine control sites outside the burn. Sites were stratified in triplicate across GIS-derived integrated soil moisture index (IMI) classes. Burning was done in 1996. Overstory species dbh and sapling species were sampled 1997, 2001, and 2008. Overstory stems were located in 2009 using range finders. Stem locations were loaded into GIS using novel techniques to quantify individual stem IMI values. …

Ecological Speciation In A Multi-Trophic Complex: Gall Midges, Goldenrods, And Parasitoids, Brenda L. Wells

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The importance of ecological interactions in the origin and maintenance of species diversity remains unclear. The current study assesses how ecological interactions shape the process of evolutionary diversification using a gall midge-host plant system in Ohio involving the gall midge, Asteromyia carbonifera (Diptera: Cecidomyiidae), and its goldenrod (Solidago) host-plants. A. carbonifera form four morphologically distinctive gall morphs and differ genetically. I studied phenology, host-plant specialization, and parasitism at three field sites in Southwestern Ohio. Phenology was assessed for twelve weeks while host-plant distribution and pressure from parasitoids were measured by monthly plot and rearing gall collections. Relative gall frequencies and …