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Full-Text Articles in Ecology and Evolutionary Biology

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones Aug 2022

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones

Theses and Dissertations

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …


Examination Of Amphibian Community And Environmental Relationships In South Texas Using Environmental Dna (Edna), Sean Michael Collins Aug 2022

Examination Of Amphibian Community And Environmental Relationships In South Texas Using Environmental Dna (Edna), Sean Michael Collins

Theses and Dissertations

Developing more efficient tools to assess amphibian biodiversity and understanding what environmental variables drive amphibian biodiversity are top priorities, as amphibians are facing extinction events across the globe. Environmental DNA (eDNA) surveys are a promising new tool to asses amphibian biodiversity. Throughout the study eDNA metabarcoding along with a targeted eDNA assay and traditional survey methods were used to provide foundational information on amphibian community assemblages throughout South Texas. Water quality, habitat characteristics and soil composition data were collected and used to examine environmental relationships. eDNA metabarcoding detected significantly more amphibian taxonomic units compared to traditional survey …


The Role Of Nest Location On The Reproductive Success Of Piping Plovers Breeding At Rockaway Beach, New York, Clara I.D. Arndtsen Jul 2022

The Role Of Nest Location On The Reproductive Success Of Piping Plovers Breeding At Rockaway Beach, New York, Clara I.D. Arndtsen

Theses and Dissertations

The study’s goal was to learn what aspects of the piping plover experience affect reproductive outcomes at Rockaway Beach Endangered Species Nesting Area. Nest location was found to help predict reproductive success. Nests further from American oystercatcher nests were likely to fledge more chicks. Reproductive success was low in 2021.


Migration Ecology Of American White Pelicans: Circannual Movement, Geographic Range, And Annual Survival, Ryo Ogawa May 2022

Migration Ecology Of American White Pelicans: Circannual Movement, Geographic Range, And Annual Survival, Ryo Ogawa

Theses and Dissertations

Responses of migratory birds to seasonal climate and long-term environmental changes have been a central theme of avian migration ecology. Atmospheric conditions (e.g., winds and thermals), climate, and land cover and land use (LCLU) are major factors influencing the flights of soaring birds. Soaring American White Pelicans (Pelecanus erythrorhynchos) (hereafter, AWPEs) migrate between the subtropical Gulf of Mexico (GOM) and the temperate Northern Great Plains. American White Pelicans are also economically important piscivorous birds, causing enormous damages to the commercial Channel Catfish (Ictalurus punctatus) aquaculture in the Southeastern US. My studies aimed to evaluate the effects …


Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro May 2022

Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro

Theses and Dissertations

Fire suppression, combined with lack of forest thinning and short-rotation, monodominant management, has drastically altered the landscape in the southeastern U.S., leading to the loss of open pine ecosystems and associated avian species. Management of open pine ecosystems is a common practice; yet, there remains uncertainty regarding how vegetation structure impacts priority species. Using empirical data, I assessed changes in species abundance and associated vegetation characteristics before and after management. I also sought to identify vegetation characteristics that influence home range establishment and microhabitat selection of Bachman’s Sparrows. Priority species were negatively associated with hardwood midstory and abundance per site …


The Effects Of Short-Term Sea Level Rise On Vegetation Communities In Coastal Mississippi, Brianna Michelle Andrews May 2022

The Effects Of Short-Term Sea Level Rise On Vegetation Communities In Coastal Mississippi, Brianna Michelle Andrews

Theses and Dissertations

Salt marshes are important habitats that provide many ecosystem services, but they are susceptible to the impacts of sea level rise (SLR), often resulting in emergent vegetation loss. In areas with enough sediment input, marshes can keep pace with SLR by gaining elevation or through upland migration. However, salt marshes in areas with limited sediment input, such as the Grand Bay National Estuarine Research Reserve, often cannot keep pace with sea level rise. Additionally, the rate of SLR is increasing making it more difficult for marshes to keep pace. To assess the short-term response of marsh vegetation to sea level …


Nesting Ecology Of Wood Ducks And Other Cavity-Nesting Ducks In Mississippi, Justin Taylor Gibson May 2022

Nesting Ecology Of Wood Ducks And Other Cavity-Nesting Ducks In Mississippi, Justin Taylor Gibson

Theses and Dissertations

Man-made nest boxes are surrogate nest sites widely used by waterfowl managers in North America to propagate free-ranging Wood Ducks (Aix sponsa) and other cavity-nesting waterfowl. I monitored 129 and 174 nest boxes in 2020 and 2021, respectively, at Noxubee National Wildlife Refuge and York Woods, Mississippi. I evaluated site-specific biotic and abiotic factors that were potentially influential on nest survival of Wood Ducks and general nesting ecology and apparent nest success of Black-bellied Whistling Ducks (Dendrocygna autumnalis) and Hooded Mergansers (Lophodytes cucullatus). Daily survival rate of Wood Ducks was negatively influenced by increasing encroaching vegetation at Noxubee NWR and …


Evaluating The Role Of Area, Isolation, And Human Behavior On Meso-Mammals In A Small Statistical Demographic Area, Brittney Palode May 2022

Evaluating The Role Of Area, Isolation, And Human Behavior On Meso-Mammals In A Small Statistical Demographic Area, Brittney Palode

Theses and Dissertations

Urbanization offers unique challenges for wildlife. The urban landscape is fragmented and changes available resources for wildlife. Human-dominated landscapes can provide food, shelter, or cover through human-subsidized resources. However, to thrive in human-dominated landscapes, wildlife must adapt or disperse, otherwise they will die. In this study, I investigated how the urban landscape and human behavior influence urban wildlife occurrence. I established 35 camera sites during April 2020. I surveyed residential property dwellers around each camera site to determine what behavior they performed that could increase species occurrence. Gray fox and coyote site use decreased with increased isolation while no species …


Assessing The Utility Of The Pmm And Mmc Indices Among Extant Hominoid Genera, Julie A. Strain May 2022

Assessing The Utility Of The Pmm And Mmc Indices Among Extant Hominoid Genera, Julie A. Strain

Theses and Dissertations

This thesis set out to incorporate extant hominoid genera into an analysis of PMM and MMC to assess utility in phylogeny and predicting known taxonomic groups. Based on previous claims, we expect PMM/pmm and MMC/mmc to perform better than M1/m1 shape and size, our baseline for success, but they do not.


An Analysis Of The Effects Of Temperature And Other Environmental Factors On Microorganismal Productivity Within Aquatic Ecosystems Using Long-Term Data From Various Lter And Ilter Sites, Andrew Dorbu May 2022

An Analysis Of The Effects Of Temperature And Other Environmental Factors On Microorganismal Productivity Within Aquatic Ecosystems Using Long-Term Data From Various Lter And Ilter Sites, Andrew Dorbu

Theses and Dissertations

Global climate change is a phenomenon resulting in more extreme weather patterns and species diversity loss. In this study, I explore the impacts of climate change on regional patterns of microbial productivity. Variation in microbial productivity was explained using temperature, salinity, and dissolved oxygen as predictors in regression models with data from the LTER and iLTER network of sites that ranged from the poles to the equator. I found a positive relationship between temperature and productivity. Antarctica and Arctic sites exhibited the strongest positive relationships supporting prior research demonstrating temperature as one of the driving forces of productivity change in …


Holocene Human Influence In The Ecuadorean Amazon, Meghan Mary O'Connor May 2022

Holocene Human Influence In The Ecuadorean Amazon, Meghan Mary O'Connor

Theses and Dissertations

The extent to which the spectacular biodiversity of Amazonia has been shaped by Pre-Columbian humans is actively debated. Forests that today appear to be pristine wildernesses may have supported complex human societies as recently as 300 years ago. Understanding human history and the potential successional trajectories that result from site abandonment are important to conservation and policy-making. The Yasuni, is famed for its human and biological diversity and yet its pre-history is poorly known. Lake Añangucocha, a small blackwater lake in northwestern Ecuador, is unusual in that it is not a riverine lake, and has the potential to provide the …


Size Structure And Intraguild Interactions Between Two Ambystoma Species, Gwyneth Daunton Mar 2022

Size Structure And Intraguild Interactions Between Two Ambystoma Species, Gwyneth Daunton

Theses and Dissertations

Intraguild interactions affect population and community structure through a combination of competition and predation. Changes in size structure influence intraguild interactions by affecting the strength and direction of these species’ interactions. I tested for size-structured intraguild interactions in temporary pond ecosystems between marbled salamanders (Ambystoma opacum) and tiger salamanders (Ambystoma tigrinum) using an outdoor mesocosm experiment. I hypothesized that 1) A. opacum survivorship and growth would be negatively impacted when both species start at a similar size because tiger salamanders grow faster and are more aggressive 2) A. tigrinum will grow slower and have lower survivorship …


Behavioral And Physiological Effects Of Heavy Metals On Fish: A Review And Preliminary Results, Diana V. Morales Mar 2022

Behavioral And Physiological Effects Of Heavy Metals On Fish: A Review And Preliminary Results, Diana V. Morales

Theses and Dissertations

Pollution, specifically heavy metal pollution, in various bodies of water has been a significant issue for decades. Research has been conducted on heavy metals and their effects on the environment, larger fish species, and humans since the 1970s (Skidmore, 1964; Adeniyi et al., 2007; Adeosun et al., 2015; Bawuro et al., 2018). It is known that zinc is a neurotoxin in some species and causes harm to the environment. It is also known that it causes harm to people if it is ingested or if they are exposed to it for long periods of time (Mahurpawar, 2015; Mizuno and Kawahara, …


Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier Jan 2022

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …


Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey Jan 2022

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …


Biotic Characteristics Of Managed And Unmanaged Coastal Dunes In The Outer Banks, North Carolina, Andrew E. White Jan 2022

Biotic Characteristics Of Managed And Unmanaged Coastal Dunes In The Outer Banks, North Carolina, Andrew E. White

Theses and Dissertations

Under future climate change and sea level rise scenarios, Natural and Nature-Based Features (e.g., dunes) that protect coastal habitat and infrastructure will be exposed to increased wave energy and storm surge. Understanding how these forces will impact coastal dunes is necessary for their continued use as protective features. Coastal dunes develop through feedback between vegetation and sediment deposition, a process complicated by species-specific growth rates and responses to burial. Wave flume studies have tested the effects of dune vegetation on erosion and found multiple plant organs across several functional types to be important for resisting erosion. Although dune building and …


Quantifying Contributions Of Climate, Geography, And Gene Flow To Divergence: A Case Study For Three North American Pines, Constance E. Bolte Jan 2022

Quantifying Contributions Of Climate, Geography, And Gene Flow To Divergence: A Case Study For Three North American Pines, Constance E. Bolte

Theses and Dissertations

Long-lived species of trees, especially conifers, often display weak patterns of reproductive isolation, but clear patterns of local adaptation and phenotypic divergence. Discovering the evolutionary history of these patterns is paramount to a generalized understanding of speciation and the processes that confer population persistence versus those that compromise adaptive potential under rapidly changing environments. Forest trees have long generation times and low migratory potential making them especially vulnerable to population fragmentation and reductions of genetic diversity due to insufficient tracking of niche optima and adaptational lags. Within clades of the genus Pinus, evolutionary histories appear to be riddled with hybridization …


Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein Jan 2022

Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein

Theses and Dissertations

In this study I attempted to further resolve the population genetic structure in the Prothonotary Warbler (Protonotaria citrea), and conducted an outlier SNP analysis and exploratory gene ontology analysis to investigate potential ongoing natural selection in the species. This analysis of population structure confirms previous work by DeSaix et al. (2019), where weak population structure was observed between eastern sites along the Atlantic Coastal Plain, and western sites in the Mississippi Alluvial Valley, possibly due to a genetic discontinuity across the Appalachian Mountains. I conducted two forms of outlier SNP analyses, a principal component analysis (PCA)-based approach to identify SNPs …


Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith Jan 2022

Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith

Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease that causes loss of upper and/or lower motor neurons, and currently has no treatment or cure available. Over 90% of cases occur spontaneously with unknown causes, highlighting the complexity of the disease, and only 10% of cases are linked to heritable genetic mutations. Numerous ALS-linked genes are conserved through evolution, and model organisms may therefore provide opportunities to understand disease pathology at a molecular or cellular level, proving instrumental in identifying therapeutic targets. ALS subtype 8 (ALS8) is caused by an autosomal dominant P56S mutation in the VAPB gene that …


Pushing It To The Limit: Determining Asian Elephant (Elephas Maximus) Olfactory Sensitivity And Discrimination Through A Behavioral Choice Task, Matthew S. Rudolph Dec 2021

Pushing It To The Limit: Determining Asian Elephant (Elephas Maximus) Olfactory Sensitivity And Discrimination Through A Behavioral Choice Task, Matthew S. Rudolph

Theses and Dissertations

Elephants have shown remarkable olfactory capabilities. Their sense of smell impacts their foraging choices, behavior, and ultimately, survival. Being able to detect a target odor can allow elephants to locate specific resources, identify threats, and find receptive conspecifics. Previous studies have shown that elephants can consistently detect target odors, but have not identified the limits of this detection. Thus, to investigate the extent of elephants’ odor detection capabilities, we tested Asian elephants in a two-step odor discrimination task. First, we investigated whether elephants could detect odors at varying levels of dilution after a training procedure, and then whether they could …


Small Mammal Community Ecology And Ectoparasite Dynamics In A Tamaulipan Thornscrub Habitat, Brandi Giles Dec 2021

Small Mammal Community Ecology And Ectoparasite Dynamics In A Tamaulipan Thornscrub Habitat, Brandi Giles

Theses and Dissertations

Small mammals play many roles in ecosystems and are known as great indicators of overall ecosystem function and health, but they are also highly competent hosts for ticks and tick-borne disease. In this study, I gathered data on small mammal community ecology and species diversity, abundance, and overall ectoparasite (i.e., ticks) dynamics in a south Texas Tamaulipan thornscrub habitat. I also assessed differences in these parameters in edge versus interior habitats across a gradient of habitat fragmentation and species assemblage. Lastly, I assessed which host and environmental factors can be utilized for predicting parasitization of small mammals in this habitat. …


Algal Biodiversity Survey Of The Middle Chattahoochee River Using Dna Metabarcoding, Amanda Howell Oct 2021

Algal Biodiversity Survey Of The Middle Chattahoochee River Using Dna Metabarcoding, Amanda Howell

Theses and Dissertations

Aquatic plants play vital roles in water systems by providing ecological services, and one group that is understudied is algae. Algae play a crucial role in water systems as bioindicators and primary producers. They can be challenging to identify with the naked eye, so researchers have been using DNA metabarcoding, where DNA belonging to specific taxa can be isolated and identified from water samples. The objective of this study was to conduct an algal biodiversity survey on the middle Chattahoochee River system in Georgia. Water samples (1L) were filtered and sent to RTL Genomics for sequencing and processing; the data …


Some (Im)Material Girls, Living In (Im)Material Worlds, With Seeds, Stars, And Shit, Matthew Weiderspon May 2021

Some (Im)Material Girls, Living In (Im)Material Worlds, With Seeds, Stars, And Shit, Matthew Weiderspon

Theses and Dissertations

This writing situates material and gestural vocabularies cultivated in my artwork in relation to my lived experience; primarily my rural upbringing in Colorado. Scattered floor dispersals, calling sounds, and bodily movements desire reconsiderations of hope in precarity through a disorientation of place, association, scale, and language.


Effects Of Precessional Forcing In The Early Stages Of The 100-K World, Molly Kingston May 2021

Effects Of Precessional Forcing In The Early Stages Of The 100-K World, Molly Kingston

Theses and Dissertations

Much of what we know about the Andes today comes from studying a heavily human-manufactured landscape. However, before the presence of human modification in this system (~13,000 years ago), past interglacial and glacial cycles, influenced by changes in Earth cycles (eccentricity, obliquity, and precession), were the cause of major landscape re-organization. The variability in intensity and duration of these events and the probable response of the plant community is not well understood. Very few records in South America extend far enough back in time to capture these changes. Those records that do exist, lack an independent chronology and instead rely …


Pre- And Post-Partum Observations Of Signature Whistle Characteristics Of The Bottlenose Dolphin (Tursiops Truncatus), Robert Dutchen Apr 2021

Pre- And Post-Partum Observations Of Signature Whistle Characteristics Of The Bottlenose Dolphin (Tursiops Truncatus), Robert Dutchen

Theses and Dissertations

This study analyzes whistle usage in an Atlantic bottlenose dolphin during birth. Findings show the mother produces two predominant whistle contours. Congruities between the whistles were compared and showed that the type 1 contour bears structural similarity to the first component of the type 2 contour, indicating combinatorial whistle construction.


Influence Of Group Change On Scent Marking In A Wild Population Of Verreaux’S Sifaka (Propithecus Verreauxi), Julia C. Dickerson Apr 2021

Influence Of Group Change On Scent Marking In A Wild Population Of Verreaux’S Sifaka (Propithecus Verreauxi), Julia C. Dickerson

Theses and Dissertations

This study analyzed scent marking rates of wild Verreaux’s sifaka during dispersals to investigate the impact of group changes on olfactory communication. Our results indicate that scent marking is affected by changes in group structure, but other methods of communication likely play a larger role in mediating group membership changes.


Body States Of Asian Elephants Within And Around Protected Areas In The Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand, Caitlyn Thai Apr 2021

Body States Of Asian Elephants Within And Around Protected Areas In The Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand, Caitlyn Thai

Theses and Dissertations

Researchers are becoming increasingly aware that studying a species’ landscape of fear or, more broadly, their emotional states, can better inform cognitive questions about how animals navigate their environments. Vigilance behaviors are one way to determine how certain species perceive and respond to risky situations. Due to rapid environmental change, large animals such as elephants are experiencing risky encounters with humans more often than ever before. This study aims to investigate Asian elephants’ expressions of body states and how they might regulate their behavior based on perceived environmental risk or change. Specifically, we investigated the behavioral responses of Asian elephants …


In Defense Of Plants: Salicylic Acid In A Host-Parasite-Pathogen System, Timothy Kyle Martin Apr 2021

In Defense Of Plants: Salicylic Acid In A Host-Parasite-Pathogen System, Timothy Kyle Martin

Theses and Dissertations

Cuscuta pentagona is an obligate parasitic plant that uses a specialized organ, known as a haustorium, to penetrate host xylem and phloem to absorb water and nutrients from its hosts. As holoparasites, they lack chloroplast and therefore cannot photosynthesize. Bidirectional movement at the haustoria raises the possibility that the parasite can transmit defense signals from one host to another, though in what form is unclear. The biotrophic feeding mode, lack of chloroplast, and bidirectional movement across the haustoria lead me to hypothesize that (1) C. pentagona as a shoot parasite would elicit a systemic acquired resistance response in a host …


Phenotypic Characterization Of Table Mountain (Pinus Pungens) And Pitch Pine (Pinus Rigida) Hybrids Along An Elevational Gradient In The Blue Ridge Mountains, Virginia, Alexander L. Brown Jan 2021

Phenotypic Characterization Of Table Mountain (Pinus Pungens) And Pitch Pine (Pinus Rigida) Hybrids Along An Elevational Gradient In The Blue Ridge Mountains, Virginia, Alexander L. Brown

Theses and Dissertations

Hybridization has played a long-standing role in the evolution of both plant and animal species and allows for the sharing of genetic information between lineages. Here, potential hybridization of a species endemic to the Appalachian Mountains, Table Mountain pine (Pinus pungens), and pitch pine (Pinus rigida) was investigated along an elevational gradient, through the use of phenotypic measurements: cone length, cone width, and needle length. Phenotypes were used to identify hybrids in a three-tiered elevational sampling method at two sites in Shenandoah National Park with the use of linear discriminant analysis. It was found that hybridization …


Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin Jan 2021

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …