Ecology and Evolutionary Biology | Open Access Articles

¬Multilocus Phylogeny Of The Lichen Family Megasporaceae, Tim B. Wheeler

Graduate Student Theses, Dissertations, & Professional Papers

The lichen symbiosis is one of the oldest studied mutualisms; in fact, Frank and De Bary coined the term "symbiosis" while studying lichens (Frank, 1877; De Bary 1879). The widespread, stable association between the mycobiont and photobiont in lichens offers an ideal system for the study of co-evolution. The recent application of molecular data to lichens has begun to unveil the complexities involved in these associations (Upreti et al. 2015, Spribille et al. 2016). Lichenized fungi make up a huge fraction of fungal diversity (Nash 2008), yet very little is known of their genetic diversity. Fungal taxonomy is notoriously difficult …

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Limited Evidence For Co2-Related Growth Enhancement In Northern Rocky Mountain Pinus Contorta Populations: Trends In Growth And Intrinsic Water-Use Efficiency Across Climate Gradients, Charlotte C. Reed

Graduate Student Theses, Dissertations, & Professional Papers

Forests sequester large amounts of carbon annually; however, the degree to which enhanced forest productivity is due to more conducive climate or CO₂ fertilization remains uncertain. Increasing atmospheric CO₂ may enhance photosynthesis and/or decrease stomatal conductance thereby enhancing intrinsic water use efficiency (iWUE). While increasing iWUE has been observed in most trees globally, this increase does not necessarily translate into greater growth. This study aims to evaluate whether responses of radial growth and iWUE to increasing CO₂ vary across climatic gradients. To investigate interactions between climate and CO₂ and their impacts on tree physiology and growth, …

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Response Of Amphibian And Invertebrate Communities To Wetland Mitigation In The Greater Yellowstone Ecosystem, Leah K. Swartz

Graduate Student Theses, Dissertations, & Professional Papers

Wetlands play a critical role in supporting freshwater biodiversity and ecosystem services, but human activities have resulted in large-scale loss and degradation of these habitats across the globe. To offset the decline of wetland area, mitigation wetlands are now frequently constructed, but their ability to replace the functions of natural habitats, including providing habitat for native fauna, remains uncertain. A recent highway reconstruction project in northwestern Wyoming caused impacts to and the destruction of multiple natural wetlands. To mitigate this loss, new wetlands were constructed along the highway corridor. To evaluate the performance of these created wetlands relative to reference …

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Contributions Of Gene Copy Number Variation To Genome Evolution And Local Adaptation Of The Cyanobacterium Acaryochloris, Amy L. Gallagher

Graduate Student Theses, Dissertations, & Professional Papers

Acaryochloris is a recently discovered genus of cyanobacteria, unique in its use of an uncommon chlorophyll as its major photosynthetic pigment, and in its peculiar genome dynamics. Members of this genus exhibit increased genic copy number variation (CNV), which is thought to be primarily derived from gene duplications and horizontal gene transfer (HGT). Acaryochloris provides an ideal system to explore mechanisms behind maintenance of gene duplicates and the influence of CNV in local adaptation. Here, I propose a mechanism for retention of gene duplicates of the bacterial recombinase, RecA, in Acaryochloris genomes and provide preliminary evidence that these paralogs are …

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K-Mer Analysis Pipeline For Classification Of Dna Sequences From Metagenomic Samples, Russell Kaehler

Graduate Student Theses, Dissertations, & Professional Papers

Biological sequence datasets are increasing at a prodigious rate. The volume of data in these datasets surpasses what is observed in many other fields of science. New developments wherein metagenomic DNA from complex bacterial communities is recovered and sequenced are producing a new kind of data known as metagenomic data, which is comprised of DNA fragments from many genomes. Developing a utility to analyze such metagenomic data and predict the sample class from which it originated has many possible implications for ecological and medical applications. Within this document is a description of a series of analytical techniques used to process …

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Drivers And Feedbacks Of The Fire-Grazing Interaction In The Northern Great Plains, Jacob E. Powell

Graduate Student Theses, Dissertations, & Professional Papers

The fire-grazing interaction is well studied in mesic grasslands worldwide, but research is lacking in semiarid systems. In addition, the fire-grazing interaction reduces the invasion of exotic forage species in mesic grasslands by increasing the scale of grazing selection and may be a tool to control invasive plants in other grasslands. We examined the principal drivers and feedbacks of the fire-grazing interaction on the strength of cattle grazing selection, forage quantity and quality, and vegetation structure and composition in two pastures in northeast Montana at The Nature Conservancy’s Matador Ranch. We also determined the influence of time since fire, within …

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Investigating The Effects Of Changes In Light Quality On Different Life History Stages Of Seagrasses, Simone Strydom

Theses: Doctorates and Masters

Seagrass meadows provide crucial ecosystem services to the coastal zone but globally are threatened. Seagrass loss to date has mainly been attributed to anthropogenic activities that reduce light quantity, such as dredging, declining water quality from urban and agricultural run-off and eutrophication. However, light quality (wavelengths of light) is also altered by these anthropogenic stressors as well as natural events. This study consisted of three main components: (1) characterising light quality to which seagrasses are exposed across a local natural estuarine-ocean gradient and with a human impact pressure; (2) the influence of monochromatic light quality (blue λ=451 nm; green λ=522 …

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Nocturnal Roost Tree, Roost Site And Landscape Characteristics Of Carnaby's Black-Cockatoo (Calyptorynchus Latirostris) On The Swan Coastal Plain, Candice Le Roux

Theses: Doctorates and Masters

There is limited information on communal roosting in parrot species of Western Australia and other parts of the world. Carnaby’s Black-Cockatoo is an endangered species that forms large nocturnal communal roosts, and for this reason they are an ideal model species to test the characteristics or factors that are associated with roost sites. Known roost sites distributed across the Swan Coastal Plain were identified and selected through the Great Cocky Count project. A minimum of five and maximum of ten individual trees were assessed at 11 roost sites with an overall total of 95 roost trees sampled. I determined the …

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Ecology Of Savanna Ecosystems In Indonesia, Sutomo

Theses: Doctorates and Masters

Tropical savannas in South East Asia are important yet understudied ecosystems. In fact, the description of savanna is limited in the Indonesian Archipelago, a region which, based on climate alone, would be expected to have mostly forest. In this thesis, I compared and contrasted the vegetation characteristics of four savannas in the wetter part of the Indonesian archipelago (Java – Bali – Lombok) to understand how fire and grazing influence their dynamics, and searched for evidence of savanna origins, maintenance, invasion by exotic/woody species and possible ecosystem transitions. Vegetation surveys, remote sensing techniques and statistical models were used to spatially …

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The Role Of The Seagrass Leaf Microbiome In Assisting Nitrogen Uptake By The Western Australian Seagrass, Posidonia Sinuosa, Flavia Tarquinio

Theses: Doctorates and Masters

Microorganisms play a key role in facilitating the cycling of several elements in coastal environments, including nitrogen (N). N is a key component for maintaining high seagrass productivity and is often the limiting nutrient in marine environments. Seagrasses harbour an abundant and diverse microbial community (the ‘microbiome’), however their ecological and functional roles related to the seagrass host are still poorly understood, in particular regarding N cycling. Microorganisms capable of mineralising dissolved organic nitrogen (DON) may play a pivotal role in enhancing N availability in coastal environments such as seagrass meadows. Thus, the overall aim of my thesis was to …

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Exploring The Impact Of Collective Bargaining Agreements On Employee Performance Management, Nana Gyesie

Walden Dissertations and Doctoral Studies

As of 2014, union density in the United States had dropped compared to union density during the 1950s. Collective bargaining agreements are the foundational agreement for all issues related to salary, benefits, and working conditions. The purpose of this multiple case study was to explore how collective bargaining agreements hindered or enabled managers from creating and sustaining high performance work practices. The conceptual framework included Walton and McKersie's work on behavioral theories for labor negotiations, human capital, and collective bargaining, and Huselid's work on high performance work practices. Fifteen respondents across 5 labor unions in Washington DC were selected through …

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Quantifying Current Sediment Deposition, Legacy Sediments, And Pre-Impoundment Vertical Accretion And Carbon Dynamics Following Dam Removal In A Recently Restored Tidal Freshwater Wetland, Melissa J. Davis

Theses and Dissertations

Damming disrupts natural sediment flow to downstream resulting in legacy sediment accumulation. Legacy sediments have been well investigated in streams throughout the Piedmont region; however, there is no research of legacy sediments following dam removal in low-gradient Coastal Plain streams. Research objectives were to: characterize legacy sediments in a low-gradient stream restoration, quantify pre-impoundment accretion and carbon dynamics, and assess current sediment deposition rates via ¹⁴C analyses within sediment cores and sediment collection tiles. Carbon accumulation and accretion rates of modern tidal sediment have reached that of the tidal relic benchmark and current sediment deposition rates are similar between …

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The Effect Of Chronic Nutrient Addition From Wastewater On Forest Ecosystems At The Rice Rivers Center, Michael Beck

Theses and Dissertations

Wastewater application to land can be a useful tool for mitigating impacts of nutrient enrichment on aquatic systems. A land application treatment system at VCU’s Rice Rivers Center in Charles City County, VA provided an opportunity to study the impact of wastewater addition on the biogeochemistry of forests representative of the Mid-Atlantic Coastal Plain. Nutrient concentrations in throughfall and leachate were measured at Treatment and Control sites to assess differences in nutrient deposition and retention. Wastewater amended plots from the Walter L. Rice education building received 20-fold (N) and 6-fold (P) higher inputs relative to Control plots and plots located …

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Behavioral And Physiological Assessment Of Zoo-Housed Heterosexual Gorilla (Gorilla Gorilla Gorilla) Troops With Multiple Silverbacks, Kaylin S. Tennant

UNF Graduate Theses and Dissertations

Based on recognized life history traits and ecology, zoos strive to house their gorillas (Gorilla gorilla gorilla) in mixed-sex groups with one mature male or silverback, multiple females, and their offspring. However, successful captive breeding programs and a nearly 50:50 birth sex ratio has created the need to house surplus males in solitary conditions or all-male groups. It is commonly believed that male western gorillas will not tolerate one another in the presence of females; however, multi-male, mixed-sex groups have been observed in the wild. For this reason, some zoos have begun experimenting with this scenario. At the …

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Ecology and Evolutionary Biology Commons^™

Full-Text Articles in Ecology and Evolutionary Biology

¬Multilocus Phylogeny Of The Lichen Family Megasporaceae, Tim B. Wheeler

Graduate Student Theses, Dissertations, & Professional Papers

Limited Evidence For Co2-Related Growth Enhancement In Northern Rocky Mountain Pinus Contorta Populations: Trends In Growth And Intrinsic Water-Use Efficiency Across Climate Gradients, Charlotte C. Reed

Graduate Student Theses, Dissertations, & Professional Papers

Response Of Amphibian And Invertebrate Communities To Wetland Mitigation In The Greater Yellowstone Ecosystem, Leah K. Swartz

Graduate Student Theses, Dissertations, & Professional Papers

Contributions Of Gene Copy Number Variation To Genome Evolution And Local Adaptation Of The Cyanobacterium Acaryochloris, Amy L. Gallagher

Graduate Student Theses, Dissertations, & Professional Papers

K-Mer Analysis Pipeline For Classification Of Dna Sequences From Metagenomic Samples, Russell Kaehler

Graduate Student Theses, Dissertations, & Professional Papers

Drivers And Feedbacks Of The Fire-Grazing Interaction In The Northern Great Plains, Jacob E. Powell

Graduate Student Theses, Dissertations, & Professional Papers

Investigating The Effects Of Changes In Light Quality On Different Life History Stages Of Seagrasses, Simone Strydom

Theses: Doctorates and Masters

Nocturnal Roost Tree, Roost Site And Landscape Characteristics Of Carnaby's Black-Cockatoo (Calyptorynchus Latirostris) On The Swan Coastal Plain, Candice Le Roux

Theses: Doctorates and Masters

Ecology Of Savanna Ecosystems In Indonesia, Sutomo

Theses: Doctorates and Masters

The Role Of The Seagrass Leaf Microbiome In Assisting Nitrogen Uptake By The Western Australian Seagrass, Posidonia Sinuosa, Flavia Tarquinio

Theses: Doctorates and Masters

Exploring The Impact Of Collective Bargaining Agreements On Employee Performance Management, Nana Gyesie

Walden Dissertations and Doctoral Studies

Quantifying Current Sediment Deposition, Legacy Sediments, And Pre-Impoundment Vertical Accretion And Carbon Dynamics Following Dam Removal In A Recently Restored Tidal Freshwater Wetland, Melissa J. Davis

Theses and Dissertations

The Effect Of Chronic Nutrient Addition From Wastewater On Forest Ecosystems At The Rice Rivers Center, Michael Beck

Theses and Dissertations

Behavioral And Physiological Assessment Of Zoo-Housed Heterosexual Gorilla (Gorilla Gorilla Gorilla) Troops With Multiple Silverbacks, Kaylin S. Tennant

UNF Graduate Theses and Dissertations