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Full-Text Articles in Life Sciences

A Multi-Scale Investigation Of Habitat Selectivity In Coastal Plain Stream Fishes, Hayley A. Robinson Nov 2019

A Multi-Scale Investigation Of Habitat Selectivity In Coastal Plain Stream Fishes, Hayley A. Robinson

Honors College Theses

Studying the habitat use of Coastal Plain fishes enables us to develop a deeper understanding of how fishes thrive in this highly variable environment. Based on previous research by Dr. Roberts and his students, Coastal Plain fishes seem to sort into two groups: (1) species selecting stream reaches that continue to flow throughout the summer (i.e., fluvial species [F]) and (2) species occurring in streams that may stop flowing in late summer (i.e., nonfluvial species [NF]). For this study, I took a detailed look at eight of these species, spanning the F-NF gradient, and asked which environmental variables (e.g., water …


Ecomorphological Variation Among Redbreast Sunfish Populations Of The South-Eastern United States, Grayson Ariel Walker Apr 2019

Ecomorphological Variation Among Redbreast Sunfish Populations Of The South-Eastern United States, Grayson Ariel Walker

Honors College Theses

Individual populations of a species will morphologically adapt to their surrounding environment. It has been noted in the past that when species are placed under similar environmental conditions, they will evolve similar morphological structures and shape variation to overcome those obstacles. Redbreast sunfish (Lepomis auritus) were sampled from three different ecoregions (mountainous, Piedmont, and coastal plain) of 4 different isolated river basins in the southeastern North America. It was hypothesized that across basins, populations would show convergent morphological adaptations to mountain, piedmont, and coastal plain condition. I indexed using site elevation as an independent variable, serving as a …


Comparing Feeding Accuracy Between High And Low Predation Trinidad Guppies, Lydia J. Bonnell Apr 2019

Comparing Feeding Accuracy Between High And Low Predation Trinidad Guppies, Lydia J. Bonnell

Honors College Theses

Efficient feeding accuracy could increase an organism’s survival. Although local adaptation in Trinidad guppies is common, the effects on accuracy are unknown. Guppies were wild caught in 2015 and 2017, filmed while capturing prey. Accuracy wasn’t different within samples but differed across samples, possibly due to the prey types used.


Identification Of Bird-Associated Nonpoint Sources Of Microbial Contamination In Sediments, Savannah D. Mullins Apr 2019

Identification Of Bird-Associated Nonpoint Sources Of Microbial Contamination In Sediments, Savannah D. Mullins

Honors College Theses

Fecal indicator bacteria (FIB), such as Enterococci, are commonly used to monitor the microbial contamination of recreational beach waters based on standards set by the United States Environmental Protection Agency. Sediment and sand may also harbor FIB and reintroduce these bacteria to the water column. Enterococci may be originated from various non-point sources such as humans and wildlife. Recent literature has shown that avian feces also harbor high concentrations of Enterococci. The purpose of this study is identify the relationship between Enterococci and avian-associated markers in sediments. Sediment samples were collected monthly from four sites at Kings Ferry Beach in …


The Role Of Local Adaptation On Biting Performance In Trinidadian Guppies, Hannah E. Cohen Jan 2019

The Role Of Local Adaptation On Biting Performance In Trinidadian Guppies, Hannah E. Cohen

Electronic Theses and Dissertations

Divergent selection pressures in populations that occupy different environments can result in phenotypic differentiation in traits that provide a local fitness advantage. Trinidadian guppy (Poecilia reticulata) populations are separated by physical barriers such as waterfalls which result in repeated shifts in selective pressures from predator avoidance in high predation environments towards resource competition in low predation environments. Such shifts in selection pressures have previously shown that a range of locally adapted morphological and behavioral traits are changed. However, the role of local adaptation on biting behaviors remains unclear. I analyzed morphological differences such as body length, jaw position, …


Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer Jan 2019

Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer

Electronic Theses and Dissertations

The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …


Effects Of Climate Variability: A Long-Term Perspective On Leaf Litter Processing In The Ogeechee River, Jose A. Sanchez Jan 2019

Effects Of Climate Variability: A Long-Term Perspective On Leaf Litter Processing In The Ogeechee River, Jose A. Sanchez

Electronic Theses and Dissertations

The Intergovernmental Panel for Climate Change (IPCC) predicts a rise in temperatures and changes to precipitation patterns for the 21st century. These changes are expected to lead to a higher frequency of extreme events such as drought and floods which lead to the alteration of the hydrology, communities, and processes of freshwater ecosystems. Leaf litter decomposition in stream ecosystems is an important component of the energy and nutrient cycle representing a food source for aquatic organisms. This has made it a tool for assessing long term responses to disturbance due to changes in the assemblage of macroinvertebrates that …


Inferring Food Web Structure To Identify Seasonal And Longitudinal Patterns In Ogeechee River Invertebrate Communities, Julien Marc Buchbinder Jan 2019

Inferring Food Web Structure To Identify Seasonal And Longitudinal Patterns In Ogeechee River Invertebrate Communities, Julien Marc Buchbinder

Electronic Theses and Dissertations

Understanding how the structure and function of aquatic communities vary across space and time is essential for proper management of freshwater ecosystems. Current management relies on rapid biomonitoring using metrics of community structure, but metrics that incorporate ecosystem processes and functions are only just beginning to see use in assessment and management. Food webs inferred from known species interactions have been proposed as a method of incorporating function into bioassessment without expending extra effort or sacrificing the cost-effectiveness of current monitoring schemes. To apply food webs in biomonitoring, it is first necessary to understand how communities and food webs vary …


Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young Jan 2019

Quantifying The Morphological And Physiological Effects Of Drought, Grass Invasion, And Fire On Longleaf, Loblolly, And Slash Pine, Laura Young

Electronic Theses and Dissertations

Climate change is altering ecosystems on a global scale, creating novel ecological scenarios with which plant species must cope. Factors such as altered precipitation and fire regimes and non-native plant invasion may negatively affect native plant species, while interactions between these stressors could magnify their impacts. The complexity of multiple stressors and the effects they have on native pine seedlings are difficult to predict without evaluating their combinations in field experiments. In a multi-year study, I investigated the effects of drought and plant invasion on three southeastern pine species under pre and post-fire conditions. We planted longleaf (Pinus palustris …


Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer Jan 2019

Wetland Biogeochemical Responses To Predicted Climate Change Scenarios, Angela R. Shaffer

Electronic Theses and Dissertations

Wetlands are one of the world's largest known carbon sinks while comprising only a small amount of the Earth's surface. However, the amount of carbon sequestered by wetlands is shrinking as droughts and human disturbance increases. Carbon in wetlands is stored through the contrast of decomposition and sedimentation of organic matter and absorption of CO2 from the atmosphere by soil microbes. Understanding how changing hydrological regimes and increased wildfires will affect wetland soil and microbial processes is important in the face of predicted climate change for future wetland conservation practices. Specifically, I seek to understand the response of southeastern …