Environment and Natural Resources Undergraduate Research Theses and Honors Research Theses

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Undergraduate Research Theses and Honors Research Theses from the School of Environment and Natural Resources. More about the School of Environment and Natural Resources Honors Program can be found at: https://senr.osu.edu/undergraduate/honorsprogram

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    Reponse of Giant Ragweed (Ambrosia trifida) Source Populations to Varying Soil Moisture Conditions
    (The Ohio State University, 2024-05) Brown, Kristen; Hovick, Steve
    Giant ragweed (Ambrosia trifida) is native to North America and an emerging invasive species in Europe and Asia. Giant ragweed is typically found in riparian areas, which are located near water sources and have relatively high soil moisture. Giant ragweed often escapes into agricultural fields where it is highly competitive with corn and soybean crops and the soil is much drier. Such incursions into crop fields have been occurring for much longer in the eastern part of the U.S. Corn Belt than in the western Corn Belt, which has led to evolved population differences in the east that are more pronounced than in the west. We hypothesized that giant ragweed populations would differ in drought tolerance due to variable abiotic conditions where they occur. Specifically, we predicted that populations of giant ragweed from crop fields would be more drought tolerant than non-crop populations and that populations from the drier western region would be more drought tolerant than populations from the east. We sourced seeds from agricultural and riparian populations in Ohio and Nebraska. In a greenhouse, we grew each population type and source under three conditions that spanned a soil moisture gradient, from saturated to dry soil moisture conditions. Performance was greatest in the driest conditions for all source populations, with higher germination percentages, higher total biomass, and earlier emergence than in either of the wetter treatments. However, Nebraska populations had a much higher germination percentage and emerged earlier than Ohio populations, which was exacerbated in drier conditions. Additionally, crop populations showed higher germination percentages than non-crop populations, especially in the driest conditions (habitat x treatment). These findings suggest that Nebraska and crop populations may be more drought tolerant than Ohio and non-crop populations, respectively. Overall, giant ragweed is more successful in areas with lower soil moisture content, such as agricultural fields, in comparison to areas with saturated soils. Furthermore, soil moisture similarly affects giant ragweed from varying population types and seed sources. The germination data suggests that there have been adaptive changes in crop populations of giant ragweed in response to soil moisture. This indicates that adaptive changes across the range of giant ragweed may be more extensive than previously thought.
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    Conductivity Level Fluctuations in Spring Creek, Ohio in Response to Road Salt Application
    (The Ohio State University, 2024-05) Dougherty, Molly; Lyon, Steve
    Road salt (NaCl) application has been increasing every year in the 21st century in Ohio. Spring Creek, a small stream located in northeast Ohio and on the intersection of two major highways, is particularly vulnerable to road salt application. Road salts can lead to negative impacts on humans and aquatic ecosystems by raising conductivity levels. Over the course of the study period, conductivity levels as well as other notable variables such as water and air temperature, and water level were measured and then plotted against each other to characterize a small streams response to raised conductivity levels. Conductivity levels in Spring Creek appeared to be highest in the winter months, having a correlation with air temperature. Conductivity and water temperature decreased as discharge increased, demonstrating that Spring Creek exhibits responsiveness to melting conditions. Results from this study can be used for management plans, regulations, and further communication regarding road salts.
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    Lead in Tap Water from University District Region, Columbus, OH: Evaluation of Lead and Copper Rule and Revisions Sampling Guidance Across Service Line Compositions
    (The Ohio State University, 2022-05) Zic, Kathryn; Lyons, W. Berry
    Lead is a potent toxin that can cause a myriad of health effects, most notably adverse effects in pregnancy and neurological changes in children. Due to the health effects of lead exposure, regulations are in place to minimize lead exposure to the public. This study focuses on lead concentrations of tap water in Columbus, OH, and how the presence or absence of a lead service line impacts household tap water lead levels. The change in sampling directives from the EPA's Lead and Copper Rule (1991) to the Lead and Copper Rule Revisions (2021) were also examined, taking both the first and fifth liters of water for analysis. Buildings were selected for sampling in north-central Columbus to include a mix of service line compositions according to published data from the Columbus Department of Public Utilities. Samples were collected using the clean hands/dirty hands technique of trace element sampling, and then analyzed for lead using an ICP-MS. Major cations and anions were also analyzed in the tap water samples. Differences in lead concentration between buildings serviced by lead lines and by non-lead lines were not significant, which may suggest that Columbus's corrosion control treatments are working. Changes in lead levels from the first to the fifth liter were significant in non-lead pipes, with liter one having higher concentrations of lead. These changes were not significant in lead pipes, though notable outliers of 1.09 μg/L and 0.38 μg/L were present in liter five. Our previous work on tap water from numerous Ohio State University campus buildings indicates low, but measurable amounts of lead in all samples with a mean concentration of 1.2 μg/L (n=20). Off-campus buildings had lower levels than the on-campus samples, with a mean concentration of 0.13 μg/L (n=31).
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    Effects of Urbanization and Habitat Fragmentation on Red-backed Salamanders (Plethodon cinereus)
    (The Ohio State University, 2018-12) Wilk, Andrew; Peterman, William
    Globally, urban environments are growing at an equal or greater rate than the human population. This growth is causing environmental stress through land use change and habitat fragmentation. These stresses, along with a host of others, are driving precipitous declines in vertebrate taxa around the world, especially in amphibians. However, the effects of habitat fragment size are understudied for these species. We tested the effects of habitat fragment size on Red-backed Salamanders (Plethodon cinereus) as they are known to persist in highly fragmented, urban landscapes. We examined abundance, genetic health, differentiation, and potential bottleneck effects between 9 urban forest patches ranging from less than 1 hectare to approximately 250 hectares. There was no apparent effect of contiguous habitat patch size on abundance or genetic health, but we did observe differentiation in 94% of cases and evidence of bottleneck effects at every site. However, the differentiation observed was not a result of overland distance or effective distance due to landscape resistance. Therefore, it is evident that abundance is a result of microclimatic conditions and that past land use history has altered the natural trajectory of these populations.
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    Predator-prey interactions under artificial lighting at night and elevated turbidity
    (The Ohio State University, 2023-12) Lincicome, Matthew; Sullivan, Mazeika; Bohenek, Jason
    Artificial lighting at night (ALAN) is a widespread anthropogenic stressor with projected negative impacts on worldwide biodiversity. As a disruption of natural lighting, ALAN has been implicated as a key mechanism increasing predation rates on prey by eliminating dark refugia for prey. ALAN correlates with urban development that has a negative impact on stream water quality by increasing erosion and sediment input, which can impede the foraging success of visual predators. These two stressors co-occur with opposite expected effects, but it is unknown how they interact. For this study, predatory largemouth bass (Micropterus salmoides) and fathead minnows (Pimephales promelas) were used as a model predator-prey system given their widespread distributions and natural predator-prey relationship. A field mesocosm experiment was conducted to investigate the effects of experimentally manipulated ALAN (0, 0.5, 3, and 10 lux) and turbidity (clear, turbid) on predator-prey interactions using these species. We measured daily and overall minnow survival and the physiological response of largemouth bass by testing blood glucose as an indicator of stress. Our analysis elucidated that turbidity had a strong effect on predator-prey interactions while there was no observable effect of ALAN, evident in the prolonged survival of minnows in turbid conditions, despite variable light intensities. Further, largemouth bass showed a significant increase in glucose response to turbidity treatments whereas lighting had no effect. This study suggests that stream management should continue to focus on mitigating erosion and sediment inputs.
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    Understanding the Distribution of Microcystin in Western Lake Erie's Food Web
    (The Ohio State University, 2023-05) Fite, Kristina; Ludsin, Stuart
    Human-driven environmental change has caused harmful algal blooms dominated by cyanobacteria (cyanoblooms) to increase in coastal ecosystems worldwide. These blooms have been threatening the biota of aquatic ecosystems by increasing hypoxic zones, reducing water clarity, and increasing exposure to cyanotoxins. One toxin, microcystin (MC), is especially pervasive in freshwater ecosystems and can accumulate in the soft tissues of organisms. However, our understanding of how MC moves through the food web remains incomplete in most ecosystems. To this end, I quantified MC levels in several common fish species and their prey inside and outside cyanoblooms in western Lake Erie, which has been experiencing a resurgence of cyanoblooms during recent decades owing to non-point source nutrient pollution and climate change. As hypothesized, I found that MC levels were higher in water, zooplankton, and several prey fishes captured inside of cyanoblooms than outside. Similarly, MC was only detected in top predators living inside cyanoblooms. Given that MC is a toxin to both fish and zooplankton, this begs the question of why organisms live in toxic cyanoblooms. In addition to discussing this question, I discuss the value of this research to agencies charged with managing Lake Erie's fisheries and the consumption of fish during the cyanobloom season.
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    Variation in Soil and Hydrochemical Characteristics in a Historically Mined Ohio Peat Bog
    (The Ohio State University, 2023-05) Engle, Kayla; Davies, G. Matt
    Carbon sequestration in peat bogs has an important potential to assist in mitigating climate change. Peat bogs act as a strong carbon sink, meaning they are able to keep large amounts of carbon out of the atmosphere and stored underground. Since peat bogs can store so much carbon, the release of these stocks can have a large impact. Degradation of peat bogs has been shown to release these carbon stocks, both harming the ecosystem and creating a negative global impact. In order to fully understand the impacts that degradation has on peat bogs, there is a need to evaluate changes in hydrochemistry as well as carbon content within the degraded bog. By using hydrochemistry, it leads to an ability to determine how a peat bog is physically and chemically altered by degradation, and this can be used to determine how these hydrochemical properties relate to an ability to properly sequester carbon. This study focused on Utzinger Bog, located in Columbus, Ohio. This site has experienced heavy mining, and the impacts of this mining on the hydrochemistry of the site has not yet been studied. Hydrochemistry was studied through the observation of pH, electrical conductivity, and water table at different locations across the site over three months. Soil samples were also taken across the site to evaluate carbon content, pH, electrical conductivity, and both total and organic bulk density. This data can be used to see how hydrochemistry and soil characteristics of a disturbed peat bog compare to undisturbed peat bogs observed in other areas of the midwestern United States. The outcome of this study is expected to show that areas of the bog that have been degraded or destroyed by human activity will have significantly different hydrochemical properties compared to bogs that are relatively undisturbed, meaning that degraded has affected the ability of the peat bog to properly function and store carbon. It was found that the basin expected to have experienced the highest level of mining had significant hydrochemical and soil property differences as compared to the basins that did not experience as much mining. When compared to other peat bogs, it was found that Utzinger Bog differs in hydrochemistry and soil characteristics, supporting the hypothesis that degradation causes an effect on peat bog hydrochemistry and soil characteristics.
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    Habitat selection in overwintering White-throated Sparrow flocks in an Ohio experimental wetland ecosystem
    (The Ohio State University, 2023-05) Rose, Anna; Tonra, Christopher
    The White-throated Sparrow (Zonotrichia albicollis) is a native songbird that breeds in the boreal and mixed forest ecosystems of Canada and northern United States and overwinters primarily in the central and southern United States. During nonbreeding, White-throated Sparrows are highly gregarious, forming large foraging flocks. Populations of the species are in decline with its population decreasing over 30 percent the last 50 years with a particularly steep decline in the eastern U.S.A. (Hill, 2022). A lack of understanding on what habitat attributes are preferred by overwintering sparrows limits our ability to determine the cause of this species' decline. This study seeks to determine what fine-scale habitat variables in forested wetland ecosystems could improve winter flock survival. I test the hypothesis that White-throated Sparrows show preferences for habitat attributes that maximize protective cover and provide food resources. I predict that flocks will demonstrate avoidance of emergent marsh patches and select for early successional forest patches with fine-scale elements such as brushpiles, young eastern redcedar (Juniperus virginiana), and Amur honeysuckle (Lonicera maackii). In the winters of 2021-23 at the Wilma H. Schiermeier Olentangy River Wetland Research Park, White-throated Sparrow flock observations and vegetation surveys were conducted for a total of 86 paired flock and random points. Logistic regression models were used to predict the probability of sparrow use for 16 single habitat attributes and 15 a priori multivariate models. Results show positive selection for three habitat attributes in the top models: percentage eastern redcedar, percentage Amur honeysuckle cover, and proximity to brushpile suggest that White- throated Sparrows have a strong preference for cover habitat as well as nutritional foraging opportunities of eastern redcedar berries. I discuss management implications, including the implications of apparent selection for sites with invasive Amur honeysuckle.
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    Using Elemental Ratios of Immobile Metal Oxides to Identify Changes in Parent Material in Central Ohio
    (The Ohio State University, 2023-05) Lashley, Mariah; Slater, Brian
    Twenty-five soil profiles located in West-Central Ohio on the Wisconsin-age till plain were studied to determine whether stable metal oxide concentrations in Ohio consistently reflect known lithologic discontinuities. The second objective was to investigate if these values indicate parent materials and can aid in their identification. Zirconium, Titanium, and Yttrium were measured in the unfractionated samples using an X-ray fluorescent spectrometer. The metal oxide ratios from these elements graphed as a function of depth showed variable results correlating with known parent materials. It was concluded that the unfractionated soils could have better represented the elemental concentrations, there were overlooked lithologic discontinuities in the field determinations, or the variable nature of some parent materials made it difficult to find correlations within the data. Furthermore, the Y: Zr ratio value suggested that it may indicate loess and till if soil samples are fractionated before XRF analysis.
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    Green Stormwater Infrastructure Planning in Midwestern Higher Education Institutions
    (The Ohio State University, 2023-05) Thiel, Abigail; Conroy, Maria Manta
    Green stormwater infrastructure (GSI) is an innovative approach to stormwater management that has the potential to provide a variety of operational, environmental, and human benefits beyond those offered by more traditional gray stormwater infrastructure systems. This study was an exploratory investigation of the degree to which public four-year universities in the Midwest incorporate GSI in their campus planning and stormwater management programs. I conducted a document content analysis of planning documents, policies, and NPDES MS4 permit program documents from sixteen universities in Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin. I then conducted semi-structured interviews with faculty and staff from The Ohio State University-Columbus campus and the University of Minnesota-Twin Cities campus to provide case study insight on these two universities. The findings from this study suggest that many universities plan for GSI, but these efforts have significant room for growth. Few universities had a GSI-specific plan or documents with sections dedicated to GSI; however, select universities and documents did offer GSI implementation strategies that can inspire other higher education institutions. Overall, greater adoption of GSI will require higher education institutions to take the initiative by creating GSI-supportive plans and management strategies that can successfully communicate across a variety of stakeholders.
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    Landscape heterogeneity drives population structure in four western bumble bee species
    (The Ohio State University, 2023-05) Sakulich, Elizabeth; Strange, James P.
    Bumble bees are critical pollinators in wild, agricultural, and urban ecosystems—providing the necessary ecological services for food and crop production. In western North America, mountain ranges serve as areas of high bumble bee species richness. However, as climate change increases temperatures and restricts montane populations to higher elevational spaces, their ability to disperse and maintain genetic diversity decreases. This genetic isolation could lead to the extirpation of local pollinator communities and an overall loss of pollinators. My project goal was to analyze the genetic diversity of four broadly sympatric species of bumble bees across mountain regions of western North America to assess habitat isolation's impact on population genetic structure. I expected species restricted to higher elevation habitats to display higher population structure and less genetic diversity across the landscape. I sampled approximately 150 bees per species from seven to eight sites across each species' range. I genotyped bees with an average of 10 loci and used FST and Bayesian Structure analysis to quantify population differentiation. Using isolation by distance and isolation by resistance analyses, I found evidence of habitat suitability restricting gene flow in species occupying both narrow and broad elevation gradients at varying degrees. Although each species showed varying degrees of genetic structure, knowing how habitat heterogeneity drives genetic structure and isolation can help guide conservation efforts and determine regions on which to focus in the face of climate change.
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    Are Seasonal Interactions Mediated by Stress Responses in a Short-Distance Migratory Bird?
    (The Ohio State University, 2021-05) Gaulke, Valerie; Tonra, Christopher
    Various stages within animals' annual cycle can affect one another and, thus, are not discrete events in time. What occurs during one period of the annual cycle (e.g. non-breeding) can alter the success or survival of animals in another period (e.g. breeding) of their annual cycle through non-lethal factors. These effects are termed “seasonal interactions” and are fueling a rapidly growing body of knowledge advancing our understanding of how populations are limited across the full annual cycle. In order to examine these seasonal interactions, this study aims to determine if they occur across nonbreeding stages in a short-distance migratory bird, the white-throated sparrow (Zonotrichia albicollis). These sparrows are quite abundant throughout the eastern U.S. and have well defined annual cycles. Nearly all studies examining seasonal interactions have focused on neotropical migrants and effects on the breeding season. I measured physiological stress during nonbreeding stages to determine if seasonal interactions exist between the stages of molt, wintering, and spring migration. I found that stress levels (measured by corticosterone in feathers) varied by stage and sex and higher stress in molt correlated with decreasing fat reserves during winter. However, higher stress in winter correlated with increasing fat reserves during winter, and later departure for spring migration. Thus, it appears stress hormones and fat interact in complex ways across the annual cycle. A complete grasp of the full annual cycle, and not just the breeding season, is critical for conservation as the world is experiencing a drastic decline in “common” migratory birds, like the white-throated sparrow.
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    Maternal Socialization Goals in Hong Kong and U.S. Families Shaped by Adoption of Socialization Goals and Sources
    (The Ohio State University, 2022-12) Arnipalli, Shanvanth; Feng, Xin
    This study utilized an inter-disciplinary theoretical framework to focus on maternal report of socialization goal adoption shaped by different cultural environments. These environments are Hong Kong in China, and Columbus, Ohio in the United States. We developed a cultural inclusive quantitative coding manual to analyze the qualitative interviews we completed. The current study included 30 European American and 32 Hong Kong mothers of mean age of 35.67 years. They are primarily well- educated, with the majority of them holding a college degree and having a high annual household income. Socialization Goal Interview was utilized to assess mothers' socialization goals such as desirable/undesirable child characteristics. The goals coded from the interviews were self-maximization, self-regulation, lovingness, decency, and proper demeanor. We also coded for sources, also known as influences, of these goals as well. The interviews were coded based on an existing coding manual by Harwood et al. (1996) and we expanded the manual based on our cross-cultural interviews. This study aimed to contextualize how mothers from both sites view their socialization goals and their accompanying sources, along with what their adoption of these factors looked like in mothers' parental practices for their children's socioemotional development. Both U.S. and Hong Kong mothers emphasized self- maximization and their socialization goals were predominantly influenced by their immediate environment (microsystem), wherein, adoption coding of goals and sources for both sites revealed that they are more inclined to reject and change their goals and practices for their children. In summation, with respect to cultural models and contemporary social contexts, the maternal report of socialization goal adoption is influenced by different cultural environments, moreover, how and what the mothers plan to change was elucidated through developed adoption coding methodology for both sites.
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    Relationships Between Plant Productivity and Diversity in Restored Prairie Ecosystems
    (The Ohio State University, 2022-12) Kieser, Ellen; Davies, G. Matthew
    Although there is a general consensus that biodiversity is important to ecosystem health, there is continual debate around the relationships at play between plant diversity and productivity in restored prairie ecosystems. Currently, two broad opinions dominate. The first states that increased plant diversity leads to higher productivity. Alternatively, diversity effects on productivity may be weak, and productivity is driven more by the presence of a few dominant, highly productive species. This study aimed to further explore these potential relationships in a restored prairie of eastern Ohio. The study site, located on reclaimed mine lands now owned by the Wilds, was initially restored in 2008. A calibrated visual observation method was used to estimate biomass for 322 study plots. This biomass data was then analyzed along with existing species data to understand how pre-seeding treatments, seed-mix type, and plant diversity relate to plant productivity. No treatments or their interactions were found to effect Shannon diversity. The interaction between seed treatment and fertilized status was found to have a significant effect on species richness. Importantly, Shannon diversity was found to have a positive effect on productivity. This finding suggests that managing for diversity within restored grassland ecosystems is an effective way to enhance ecosystem function and services.
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    The Spatial and Temporal Variation of eDNA in Mudpuppy (Necturus maculosus) Detection in Alum Creek, Ohio
    (The Ohio State University, 2022-05) Mancini, Alisa; Peterman, William
    Nearly 90% of Ohio's aquatic species are reliant on streams, which face many threats that contribute to habitat loss. The common mudpuppy (Necturus maculosus) is a native Ohio salamander that inhabits rivers and streams. The conservation status of mudpuppies is currently unknown. Due to widespread riparian habitat loss and alteration, as well as modification of river flows, there is potential for mudpuppy populations to be extirpated from waterways where they historically occurred. To assess the current distribution of mudpuppies, a reliable surveillance method is needed. One such method is environmental DNA (eDNA), which allows for the detection of organisms without seeing, hearing, or capturing the organism itself. eDNA is DNA that is extracted from any type of environmental sample, such as soil, water, or air, that is produced from shedding, excreting, or decaying. eDNA is becoming more commonly used for studying and monitoring aquatic species, such as amphibians, fish, and mammals. Many factors, such as organism mass, sun exposure, temperature, distance to the organism, and seasonal activity can impact detection probabilities. In order to accurately quantify mudpuppy distributions using eDNA, factors that influence detection seasonally and in relation to potential mudpuppy habitat must be understood. Through a greater understanding of these variables, eDNA methods can become more reliable and efficient, allowing for data to be gathered on mudpuppy populations faster than traditional methods. In this study, I assess temporal and spatial aspects of mudpuppy detection when using eDNA in relation to environmental factors, hydrological factors, and habitat suitability. Results from this work will help refine protocols for future statewide surveillance of mudpuppies.
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    ANALYSIS OF REMOTELY SENSED CHANNEL WIDTH OBSERVATIONS USING HIGH-ACCURACY SHORELINE TRACKING ON ALASKAN RIVERS
    (The Ohio State University, 2022-05) Wadkowski, Kylie; Durand, Michael
    Remotely sensed observations have proven to be a vital data source when analyzing river flow, particularly in resource-limited regions. Although remote sensing is an excellent alternative to gathering large amounts of field data, some uncertainty is commonly associated with satellite datasets. River discharge calculated via remotely sensed width, height, and slope is likely biased due to the uncertainty contained in these observations. A primary step in understanding this error is evaluating the uncertainty within these individual variables. Here I took an important step towards analyzing channel width predictions by walking the shorelines of 3 rivers in Alaska: the Knik River, the Tanana River, and the Nenana River. Specifically, I tracked the rivers' channel shorelines using the Bad Elf GNSS Surveyor. Following the post-processing of this data, the tracked shoreline path was compared to a classified water mask of the river, created using 1.2m resolution WorldView satellite imagery. Every 10 meters, segments were drawn perpendicular to the river's centerline, measuring the distance between the tracked shoreline (via Bad Elf) and predicted water pixels using the classified river mask. Overestimates resulted in a positive value, while negative values represented an underestimate of the water mask relative to the Bad Elf path. Overall, the averaged shoreline error, or bias, was an overestimate, at 4.7m. Furthermore, the mean absolute error (MAE) for all rivers was 8.2m, with a standard deviation (SD) of 6.9m. When evaluating the rivers on separate terms, the Knik, Nenana, and Tanana had relative MAEs of 7.0m, 7.6m and 10.3m. Lastly, the percent bias was calculated by dividing shoreline bias by shoreline mean absolute error. The Knik had the highest percent bias of 96.4%, revealing the important role bias played in the shoreline MAE. Shoreline error documented in this study is not identical to width error. If shoreline error is dominated by georegistration error, then width error may be less than shoreline error. If georegistration error is small, then width error may be up to twice as large as shoreline error. These results provide implications for a better understanding of the accuracy of current high-resolution imagery while giving insight into the source of width errors in today's datasets.
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    Effect of Turbidity on the Reaction Distance of Green Sunfish (Lepomis cyanellus) and Bluegill Sunfish (Lepomis macrochirus) in Columbus, Ohio
    (The Ohio State University, 2022-05) Oriyo, Katherine; Gray, Suzanne
    Elevated turbidity (suspended particles) from organic (algae) and non-organic (sediment) sources in aquatic systems has become a problem of increasing concern globally as it alters the visual environment for fishes. Despite evidence for decreased visual detection thresholds in predator fish under turbid conditions, few studies investigate how this may affect predators with different visual abilities. We tested to see if two native predator centrarchid (sunfish) species that prefer clear or turbid waters react differently to changes in turbidity level. Bluegill (Lepomis macrochirus) are typically found in relatively clear waters, while Green Sunfish (Lepomis cyanellus) can be found across a wide variety of turbidity levels suggesting that they may have better vision or better utilize other sensory modes (e.g., chemoreception). Therefore, we expected Green Sunfish to have longer reaction distances (i.e., the maximum distance at which a fish reacted to a prey item) in turbid water compared to Bluegill. Fish were collected from the Olentangy River near the OSU Schiermeier Olentangy River Wetland Research Park and held in tanks at the outdoor mesocosm complex. We conducted foraging response trials to measure reaction distance under a clear control (< 5 NTU) and a sedimentary turbidity (20 NTU) treatment. Reaction distance (cm) was measured from recorded videos of trials. Fish weight (g) and total length (cm) were measured after trials. Due to logistical difficulties, we were only able to test Bluegill under the clear control treatment. Therefore, we tested for a difference in reaction distance between species in clear water and separately tested if reaction distance differed between turbid and clear treatments for Green Sunfish only. No significant difference in reaction distance to prey was found between species in clear water only or within Green Sunfish only between treatments. Additionally, fish length did not have a significant impact on reaction distance. It is possible that acclimation time to lab conditions was not sufficient or that the prey item used was not appropriate. While results showed no effect of turbidity on reaction distance in two common fish species, further study may be required to eliminate confounding variables so that significant conclusions may be drawn.
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    Stress Response of a Common Fish to Changing Urban Stream Temperatures
    (The Ohio State University, 2018-12) Bajakian, Levon; Sullivan, Mažeika
    Urban streams often have higher average and more variable temperatures than forested streams. However, the effects of anthropogenically influenced water temperatures on fish condition are not well understood. This study aimed to quantify the impacts of urbanized stream temperatures on the physiological stress response of Creek Chubs. Trial 1 was conducted for six weeks and the treatment group was subjected to a temperature regime of (17-26°C), while Trial 2 was conducted for 9 weeks and the treatment group was subjected to a temperature regime of (24-26°C). In both trials, the control groups were subjected to a constant 21°C, the optimal growth temperature of Creek Chubs, while the treatment groups' thermal regimes were based on diurnal temperature profiles that simulated urban stream temperatures in Columbus, Ohio. Body condition (length and weight) along with blood-plasma glucose concentrations were measured as indices of stress. Over the duration of the trial, the treatment group Creek Chubs in Trial 1 on average gained 0.68 g more weight and exhibited blood-plasma glucose concentrations 16.4% lower than that of the control group. Meanwhile, over the course of Trial 2, Creek Chubs in the treatment group on average gained 1.66 g less weight and exhibited blood-plasma glucose concentrations 25.1% higher than those in the control group. The results of this study offer insight into some the potential underlying mechanisms regarding thermal stress while demonstrating the need for further research.
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    Effect of Water Treatment Residuals and Microcystin on Soil Chemical Properties, Soil Arylsulfatase Activity and Microbial Community Composition
    (The Ohio State University, 2021-12) Jobe, Kathryn; Basta, Nicholas; Dick, Richard
    Microcystins (MCs) are monocyclic heptapeptides that are produced by the cyanobacteria, Microcystis, and have high structural variability. They are hepatotoxins and therefore, pose health risks to humans and animals who consume them. Application of MC contaminated water treatment residuals (WTR) to agricultural fields can potentially pose a threat to the soil ecosystem in terms of soil health and food production. Therefore, developing a method to quantify the total concentration of MC in WTR is needed in order to determine the fate and toxicity of MC in the environment. In this study, a MC extraction method was successfully tested, and two out of eight WTR samples analyzed (WTR 2 and 6) had the highest concentrations of MC while WTR 3 had no detectable MC. To determine the effect of MC on soil microbial properties, a 4-week incubation study, using a clay loam and sandy loam soil from northwestern Ohio, was conducted. The treatments were: WTR (no MC), WTR+MC, and MC. The treatments were analyzed for soil chemical properties, arylsulfatase activity, and microbial community composition by microbial phospholipid fatty acids (PLFAs). In both soils, the pH and EC significantly increased in all treated soils, whereas available P content significantly decreased in all treatments. Following the addition of MC in the sandy loam soil, arylsulfatase activity significantly increased. Application of MC and WTR+MC to both soils significantly increased total PLFA, gram-negative bacteria, and total fungal concentrations. The WTR treatment had a significant effect on gram-negative bacteria in the sandy loam. The gram-negative to gram-positive bacteria biomass ratio significantly increased in all the treatments in the clay loam and sandy loam. In addition, each treatment significantly decreased the microbial PLFA stress ratio (17:0cyc and c19:0cyc divided by 16:1w7c and 18:1w7c) in the clay loam and sandy loam. The results indicate that the application of MC, with or without WTR, stimulates the soil microbial community.
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    The Effect of Fuel Moisture Content on the Flammability of Goldenrod in Prairie Ecosystems
    (The Ohio State University, 2021-05) Reuschling, Madeline; Davies, G. Matt
    Land use change across North America has greatly reduced the extent of prairies and grasslands and replaced them with agriculture. Grasslands and prairies provide biodiversity, habitat for many animals and pollinators, and ecosystem services. In Ohio, prairies did not have a large extent, but were known to exist in small patches representing the furthest reaches of western grasslands. Now, what is left of such prairies are small, remnants that lack resiliency and diversity, which makes restoring them necessary to conservation efforts. Canadian goldenrod (Solidago canadensis) is a native species, but it can become invasive within restored prairies and old fields creating monocultures that reduce the species richness and diversity. Fire is likely a vital ecological disturbance within prairies, but goldenrod-dominated areas are may be difficult to ignite and burn. Goldenrod also greatly benefits from burns, due in part to suitable regeneration conditions created by fires and their early successional traits. To better understand fundamental controls on the potential for prescribed burning in restored prairies the flammability of goldenrod was investigated. Field data was collected during spring and autumn 2019 to determine variation in fuel moisture content (FMC) with weather and how FMC varies vertically throughout the fuel bed. Weather data was taken on sampling days from Waterman Farm weather station and applied to the Canadian Forest Fire Danger Rating System to calculate the daily Fine Fuel Moisture Code (FFMC). Lab tests were conducted by heating samples of goldenrod of different FMCs in a quartz epiradiator and measuring ignitability, sustainability and combustibility. The impact of a pilot flame on ignition processes was also examined. Goldenrod FMC was lowest at the top of the plants in spring, with greater fire danger ratings. Autumn FMC was not impacted by fire danger rating. Flammability tests showed that time to ignition was shortest at low FMCs. The duration of flaming and flame heights were greatest with lower FMCs. When comparing the flammability metrics to the FFMC values calculated from field data, there was a correlation between greater flammability and greater FFMC. Overall, the results indicated that flammability was greatest at the lowest FMCs, specifically at around 15% and lower, which is a significant discovery. The flammability metrics determined that faster ignition, higher flame heights, and longer durations of flaming would likely lead to the spread of fire throughout fuels and greater consumption of goldenrod. Field data suggests that goldenrod has the lowest FMC in spring, at the top of the plant, which can alter fire behavior. Fine fuel moisture codes increased with decreasing FMCs and were positively correlated to flammability metrics. Fine fuel moisture codes of 70-74 and above strongly indicate increased flammability of goldenrod.