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Full-Text Articles in Life Sciences

Molecular Biodiversity Of Foraminifera, Rabindra Thakur Apr 2023

Molecular Biodiversity Of Foraminifera, Rabindra Thakur

Masters Theses

Foraminifera are a diverse clade of mostly shell-building single-celled organisms. Estimation of foraminiferal diversity is critical for understanding past and present climatic conditions, as they are highly sensitive to environmental perturbations. Biodiversity estimates of foraminifera began with the counting of test (i.e., shell) microfossils composed of calcium carbonate, as they are well preserved in sediment samples. However, this view has changed with molecular biodiversity estimates, which suggest that early-diverging single-chamber (i.e., "monothalamid") species that lack preservation ability are more diverse than anticipated. Although biodiversity estimates of foraminifera at the molecular level have changed our perceptions, they possess various challenges, especially …


A Biodiversity Survey Of The Soil Crusts Of The Geographically Isolated San Nicholas Island, California, Usa And Description Of Species In Three Genera (Atlanticothix, Pycnacronema, Konicacronema) Previously Restricted To Brazil Using A Polyphasic Approach To Cyanobacterial Taxonomy, Brian Jusko Jan 2023

A Biodiversity Survey Of The Soil Crusts Of The Geographically Isolated San Nicholas Island, California, Usa And Description Of Species In Three Genera (Atlanticothix, Pycnacronema, Konicacronema) Previously Restricted To Brazil Using A Polyphasic Approach To Cyanobacterial Taxonomy, Brian Jusko

Masters Theses

San Nicholas Island, California, USA is a geographically-isolated island that experiences a semiarid climate and exhibits significant topographic and geologic diversity. Access to the island is restricted to the public and, as a result, only one previous study has been done on the algal biodiversity of its biological soil crusts. The previous study used morphology as the sole basis of species identification, and it was the aim of this study to corroborate and expand upon the results by including molecular data. Using 16S rRNA and 16S–23S ITS sequences and phylogenetic analyses, a diverse set of taxa were identified and are …


Conservation Of Terrestrial Salamanders Through Hemlock Woolly Adelgid Management In Eastern Hemlock Forests Within Great Smoky Mountains National Park, Jonathan Lawrence Cox Dec 2020

Conservation Of Terrestrial Salamanders Through Hemlock Woolly Adelgid Management In Eastern Hemlock Forests Within Great Smoky Mountains National Park, Jonathan Lawrence Cox

Masters Theses

Hemlock woolly adelgid (Adelges tsugae; HWA), an invasive aphid-like arthropod, was first documented on the east coast of the United States in the 1950s. HWA is an herbivore which primarily feeds at the needle base of hemlock tree species (Pinaceae: Tsuga). With no evolutionary defenses and few biotic controls, the eastern and Carolina hemlock (Tsuga canadensis and Tsuga carolinensis) serve as the primary diet of HWA in eastern North America. The invasive pest began to spread rapidly throughout the hemlock’s range causing defoliation and death of the trees within 4 – 10 years. With the …


The Ecological Value Of Spruce Plantations In Massachusetts, Calvin Ritter Jul 2020

The Ecological Value Of Spruce Plantations In Massachusetts, Calvin Ritter

Masters Theses

The establishment of monoculture plantations of exotic tree species is common practice for supplementing native timber stocks. Such plantations typically provide inferior habitat for wildlife compared to native forest, which may result in a net reduction in biodiversity. However, some studies report that plantations may increase net biodiversity at the landscape scale by introducing novel habitats or supplementing existing natural forests. Using point count surveys, I examined six mature Norway spruce (Picea abies) plantations in western Massachusetts in 2016 and 2017 to evaluate bird use of these habitats relative to native forest stands. Count data were analyzed using …


Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney Jul 2019

Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney

Masters Theses

Trees provide countless environmental, economic, and societal benefits to the urban environment, and may become increasingly important to maintaining environmental quality and human well-being in the face of increasing urbanization and climate change. However, trees in these urban areas are rapidly diminishing across the United States. Much of this loss can be prevented with proper planning and management, focused on selecting tree species that are both well-suited to the area’s growing conditions and able to survive the many stress factors in an urban setting. Choosing which tree species to plant in Massachusetts is especially challenging considering the lack of resources …


Urban Biodiversity Experience And Exposure: Intervention And Inequality At The Local And Global Scale, Evan Kuras Mar 2019

Urban Biodiversity Experience And Exposure: Intervention And Inequality At The Local And Global Scale, Evan Kuras

Masters Theses

As cities expand globally, researchers must clarify how human activities and institutions shape biodiversity and conversely, how ecological processes shape human outcomes. Two features of contemporary cities motivate this thesis. First, urban residents, and especially children, are spending less time in nature and consequently, miss out on healthy and formative experiences with biodiversity. Second, residents with the least access to biodiversity tend to be those with the lowest socioeconomic status (SES). Together, these patterns convey a multi-layered environmental injustice: not only might urbanites become increasingly estranged from biodiversity, disinterested from its conservation, and disconnected from its benefits, but these outcomes …


A New Adaptive Landscape: Urbanization As A Strong Evolutionary Force, Lauren Christie Breza Dec 2015

A New Adaptive Landscape: Urbanization As A Strong Evolutionary Force, Lauren Christie Breza

Masters Theses

Urbanization is rapidly increasing as human population growth steadily grows, but there is little consensus of the ecological consequence of this population shift and almost no information of the evolutionary consequences for local biodiversity. Nearly two-thirds of the world’s population will live in city centers by 2050 with profound impacts on landscapes that can act as important agents of selection. This study aims to identify 1) the net effect of urbanization on species richness, 2) how phylogenetic diversity varies between urban and rural sites, and 3) the strength of urbanization as a selection pressure. First, a meta-analysis was conducted in …


A Molecular And Morphological Investigation Of The Springtail Genus Orchesella (Collembola: Entomobryomorpha: Entomobryidae), Catherine Louise Smith May 2015

A Molecular And Morphological Investigation Of The Springtail Genus Orchesella (Collembola: Entomobryomorpha: Entomobryidae), Catherine Louise Smith

Masters Theses

Chapter 1 is devoted to a molecular overview of the North American members of the springtail genus Orchesella using mitochondrial and nuclear DNA. Both genes strongly support the presence of four major clades within Orchesella. Chapter 2 is a morphological revision of the species near Orchesella celsa Christiansen & Bellinger. Five new species are described based largely on chaetotaxonomical differences in. Chapter 3 is an investigation into the origins of United States populations of two introduced European members of the genus, Orchesella cincta Linnaeus and Orchesella villosa Linnaeus. Mitochondrial data between populations from the two continents indicates multiple introductions for …


Predictive Modeling Of Floral Species Richness In Michigan Prairie Fen Communities, Nichole R. Mason Dec 2014

Predictive Modeling Of Floral Species Richness In Michigan Prairie Fen Communities, Nichole R. Mason

Masters Theses

Prairie fens contain high levels of floral biodiversity, including 19 state threatened or endangered plant species, and are classified as rare and vulnerable communities by the Michigan Natural Features Inventory. The objective of this thesis was to develop multiple-regression (MR) models that reliably predict total, native, and invasive floral species richness for use by conservation organizations. Floral biodiversity surveys were conducted in eight southern Michigan prairie fens during the 2012 growing season. Simple linear regressions between fen size and biodiversity were used to optimize sampling strategy and effort (i.e., number of transects and plots per transect) in surveys conducted in …


Molecular Systematics Of The Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke Aug 2013

Molecular Systematics Of The Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke

Masters Theses

The subfamily Phasiinae (Diptera: Tachinidae) is composed of obligate endoparasitoid flies that attack heteropteran insects, many of which are important agricultural pests. To lay a foundation for future studies in phasiine life history and their potential for use as biological control agents, the phylogenetic relationships within Phasiinae were explored using nucleotide sequences of two genes, CAD and LGL. A total of 63 taxa for CAD and 73 taxa for LGL were included in the analyses, representing 58 genera. Maximum likelihood inference methods were employed to reconstruct phylogenetic relationships in separate analyses of each gene and in a combined dataset. Phylogenetic …


Selected Costs And Benefits Of Protecting Vital Wildlife Habitats While Producing Biofuel, Benjamin Lewis Totty May 2013

Selected Costs And Benefits Of Protecting Vital Wildlife Habitats While Producing Biofuel, Benjamin Lewis Totty

Masters Theses

The objective of this study is to estimate selected costs and benefits of meeting the 2022 biofuel production mandates using switchgrass as the feedstock. This study involves the simulation of three scenarios to evaluate the cost of protecting and promoting biodiversity while producing switchgrass for biofuel. Two models are used in this study. The first, the Biofuels Facility Location Analysis Modeling Endeavor (BioFLAME), was developed at the University of Tennessee to study biorefinery location, feed stock source areas and costs associated with biofuel production. The second model was developed by the Nature Conservancy as part of Tennessee’s State Wildlife Action …