Biodiversity Commons^™

Tree Canopy Cover Influences Habitat Use Of Breeding Birds At Jack Mountain Wildlife Management Area, Kaleigh Thomas

Honors Theses

Across the United States, bird populations have declined due to habitat loss. To better understand habitat use by birds, researchers observed populations at Jack Mountain Wildlife Management Area in southwest Arkansas. Students at Ouachita Baptist University surveyed 94 point count locations to estimate species diversity (total number of species observed) and species abundance (total number of individuals observed). At each point, students recorded the percentage of tree canopy cover, ground cover, midstory cover, and shrub cover. These variables were used as explanatory variables in multiple regression analyses to determine which variables were influential in explaining variation in species diversity and …

Towards Sociobiogeochemistry: Critical Perspectives On Anthropogenic Alterations To Soil Nitrogen Chemistry Via U.S. Urban And Suburban Development, Christopher D. Ryan

Dissertations, Theses, and Capstone Projects

The ecological impacts of changes to land use are relevant to concerns about climate change, eutrophication of waterbodies, and reductions in biodiversity. As a foundational component of ecosystem functioning, changes to soil biogeochemistry have significant effects on overall ecosystem health. With cities continuing to grow and develop in extent, the impacts of urbanization and suburbanization on soils are of particular concern. Despite a wide range of natural climatic and geologic conditions, several factors have driven similar patterns of land transformation and management across the United States. In particular, federal initiatives including the Home Owners Loan Corporation, the Federal Housing Administration, …

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …

Assessing Endophyte Frequency Distributions And The Effect Of Epichloë Brachyelytri In The Chemotypic And Genotypic Diversity Of Brachyelytrum Erectum, Rachel Ann Sneed

Theses and Dissertations--Plant Pathology

Seed-transmissible epichloid fungal endophytes are best known for their roles as defensive mutualists in cool-season grasses. Historically, the discovery of fungal endophytes was driven by investigations of plant toxicity to livestock, followed by extensive study of their alkaloids and protection against insects and nematodes. Epichloae can produce four classes of alkaloids: ergot alkaloids, lolines (saturated aminopyrrolizidines), indole–diterpenes, and peramine. It is increasingly evident that these hereditary symbionts have much more diverse chemical profiles both in individual populations and between them. To this end, differences in chemotypic profiles of these symbionts may translate to different evolutionary and environmental advantages across plant …

A Conservation Model: Costa Rican Conservation Strategies Effectively Preserve Their Threatened Primates, Ryan Belmont

Regis University Student Publications (comprehensive collection)

The wildlife of Costa Rica has experienced various anthropogenic threats over the last century including climate change and agricultural expansion. The mantled howler monkey (Alloutta palliata), Central American spider monkey (Ateles geoffroyi), white-faced capuchin (Cebus imitator), and the Central American squirrel monkey (Saimiri oerstedii) are Costa Rica’s native primates that face several anthropogenic threats such as deforestation for agriculture and climate change. In response to increased threats to its four native species of non-human primates, Costa Rica has implemented effective governmental conservation tactics such as the Payments for Environmental Services program, ecotourism …

Addressing Water Hyacinth (Pontederia Crassipes) Impacts On Aquatic Biota In Lake Okeechobee, Joseph Salerno

All HCAS Student Capstones, Theses, and Dissertations

The incursion of water hyacinth, Pontederia crassipes in Lake Okeechobee has resulted in management systems to be implemented to reduce the coverage of the invasive macrophyte. Its residence in the Lake Okeechobee ecosystem and the effects it has on organisms in the lake, whether it be positive or harmful is unknown. This study attempted to assess the potential effects that water hyacinth has on aquatic biota in Lake Okeechobee. Biotic data were collected on open water, water hyacinth covered, and native vegetation covered habitats via hook-and-line fishing, electrofishing, baited minnow traps, and the sampling of plant roots over a thirteen-month …

Psammocora Stellata Distribution At Devil's Crown, Floreana Island, Galápagos Islands, Ecuador, María José Guarderas Sevilla

All HCAS Student Capstones, Theses, and Dissertations

In the Galápagos Archipelago, the free-living nodular coral Psammocora stellata is a common species that does not form reef structures. However, it is a key component of the ecosystem by increasing habitat complexity and, consequently, species diversity. This species experienced a drastic decline in Devil’s Crown channel, Floreana Island, where it disappeared after the 1982-83 El Niño-Southern Oscillation, presumably by displacement of unattached colonies by strong surface waves and currents. This assemblage has now recovered to pre-impact levels. A combination of underwater photoquadrats from 2007 and 2009 and recent (2023) orthomosaics were used to determine changes in coral densities and …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

Novel Microbial Guilds Implicated In N2o Reduction, Guang He

Doctoral Dissertations

N₂O is a long-recognized greenhouse gas (GHG) with potential in global warming and ozone depletion. Terrestrial ecosystems are a major source of N₂O due to imbalanced N₂O production and consumption. Soil pH is a chief modulating factor controlling net N₂O emissions, and N₂O consumption has been considered negligible under acidic conditions (pH <6). In this dissertation, we obtained solids-free cultures reducing N₂O at pH 4.5. Furthermore, a co-culture (designated culture EV) comprising two interacting bacterial population was acquired via consecutive transfer in mineral salt medium. Integrated phenotypic, metagenomic and metabolomic analysis dictated that the Serratia population excreted certain …

Population Genomics, Ecology And Conservation Of Asterias Sea Stars In The North Atlantic, Melenia I. Giakoumis

Dissertations, Theses, and Capstone Projects

Uncovering how species respond to environmental change is a central question in biology (Ehrlén & Morris 2015; Habibullah et al. 2022). It is the key to elucidating the past, understanding the present and predicting the future of species’ population dynamics. This dissertation investigates the influence of environmental change on intertidal species’ distributions and genomics at several timescales, with implications for conservation.

Environmental changes have occurred throughout history, on a geological scale, and have shaped the global patterns of species’ distributions and population sizes. Biologists have long studied how geological history has shaped species distributions (Sanmartín 2012) in both terrestrial (Liu …

Changes In Peatland Soil Fauna Biomass Alter Food Web Structure And Function Under Warming And Hydrological Changes, Trevor L. Pettit

Electronic Thesis and Dissertation Repository

Short-term climate perturbations affect both predator and prey species that comprise soil communities, and alter carbon flux. I used a mesocosm experiment to model the effects of experimentally-imposed temperature and moisture conditions that simulate potential future conditions during climate perturbations, on peatland soil food web flux and soil carbon sequestration after three-weeks of experimentally imposed conditions, and then again after an additional three-week recovery under control conditions. I compared system resistance and resilience, and modelled carbon (C) and nitrogen (N) fluxes throughout the mesocosm experiment. There was a lack of resistance of the soil food web to perturbation shown by …

Predicting Marine Teleost Responses To Ocean Warming And Pollution, Akila Harishchandra

Electronic Theses and Dissertations

Ocean warming and pollution are two detrimental anthropogenic factors causing rapid marine ecosystem degradation recorded in the past decades. These factors alter the marine environment intolerable for many marine species, forcing them to either adapt or shift their contemporary habitat ranges to reduce the extinction risk embedded with environmental degradation. Estimating marine species’ habitat range shifts, and their potential for developing adaptive mechanisms are critical for ecosystem conservation and management, human health risk assessment, and climate change vulnerability assessments. Given that, for the first chapter of this thesis, we focused on developing a species distribution model (SDM) integrating marine species …

Effects Of Large Wood Additions On Basal Resources, Macroinvertebrates, And Ecosystem Processes In The Narraguagus River, Maine, Val Watson

Electronic Theses and Dissertations

Ecological restoration is an increasingly common practice across ecosystems, and current practices aim to restore the biological and physical processes underlying ecosystem function, often for the sake of endangered higher-level consumers. Studies of restoration outcomes often report few or inconsistent ecological changes, and monitoring of restoration projects rarely measures ecological processes. Monitoring also usually measures outcomes at a single scale, despite the prevalence of scale- dependent phenomena across ecosystems. My thesis uses measurements of ecological processes to assess restoration response and evaluates responses across multiple scales. I focus here on a long-term large wood addition project on the Narraguagus River …

Factors Affecting The Distribution Of Malayan Sun Bear In Htamanthi Wildlife Sanctuary, Northern Myanmar, Min Hein Htike

Masters Theses

To understand the modeling challenges and to examine the important factors considered in Malayan sun bear (Helarctos malayanus) distribution studies, we reviewed 33 peer-reviewed articles published from 2003-2023. These studies used 54 environmental or anthropogenic variable types to investigate the distribution, habitat preference, and home range composition of sun bears. Most variable types are human disturbance (n=4), climate (n=3), topography (n=1), vegetation (n=11), or other ecological factors (n=3). Nevertheless, a number of rarely used variables might also be useful to include in future evaluations (i.e., food abundance), and observational evidence suggests that predator occurrence could also be informative. …

The Community Ecology Of Ants On The Cumberland Plateau And A Taxonomic Redescription Of The Genus Stenamma Westwood, 1839 (Hymenoptera: Formicidae: Myrmicinae) In A Southeastern Treatment, Zachary Brown

Theses and Dissertations

Grassland communities represent major biodiversity hotspots across the United States. Among these grassland types is the short-leaf pine savanna, a major historical habitat along the Cumberland Plateau. The Cumberland Plateau’s grasslands are under threat due to land use changes such as urbanization and land conversion to pasture and hardwood forests. This study seeks to better understand the community ecology of ants on the Cumberland Plateau using powerlines as a comparison to degraded and historic habitats. Ants have a preference between open sites and forested sites, a separation of 44.5% on a DCA. The Simpson diversity places the short-leaf pine savanna …

The Effects Of Dormant Season Burning And Flooding On Invasive Cattail, Typha X Glauca, On Rainy Lake And Lake Kabetogama In Northern Minnesota, Erika Meints

All NMU Master's Theses

Typha x glauca is one of the most invasive plants in North America. The plant exhibits hybrid vigor and displaces native flora by rapidly forming dense monotypic stands that can break free from the substrate and form floating mat types when established. I tested the effects of prescribed burning, on Typha x glauca in wetlands to adjacent large lakes in Voyageurs National Park in northern Minnesota. My team surveyed four wetlands that were burned in late winter of 2020-21, and six that were unburned controls. Pre-burn data was also collected for all ten wetlands. Pre-flooding data from other wetlands within …

Monitoring The Effects Of Poultry Waste On Fishes And Macroinvertebrates In The Sabine River, Karley R. Parker

Biology Theses

Freshwater is a vital resource that provides life and sustainability for almost all organisms on Earth. It is important to maintain its health and protect it from emerging pollutants that pose a threat to the organisms that use it. Pollution continues to threaten the well-being of the environment’s freshwater sources all around the world that could lead to damaging effects in the future. The Sabine River is a major freshwater resource in the east Texas and western Louisiana areas that provides a habitat for thousands of organisms as well as other domestic uses for humans. In 2019, a waste discharge …

An Ecological Survey Of East Texas Salamanders Across The Camp Tyler Outdoor Field School In Smith County, Texas, Justin C. Hunt

Biology Theses

Amphibians are a unique class of organisms with a very long and storied evolutionary history of survival. Many modern amphibian clades occupy several vital ecological roles within their native freshwater environments. One of these roles, typically includes functioning as an ecological indicator species, whereby the presence of stable and diverse populations of many amphibian species, including salamanders, within a freshwater ecosystem have long been considered ecological indicators of good habitat quality and stable ecosystem health. Similarly, salamanders also function as important members of their local food webs and act as valuable mediators of complex trophic hierarchies to facilitate nutrient cycling …

Vascular Plants Of The Caribou-Targhee National Forest And Curlew National Grassland In Southeastern Idaho, Western Wyoming, And Northern Utah, Michael Daines

Electronic Theses & Dissertations

Due to a historical paucity of collections from and the absence of a comprehensive floristic treatment for parts of the Caribou-Targhee National Forest and Curlew National Grassland, an updated inventory for the area was needed. I present an annotated checklist of the vascular plants documented from the Caribou-Targhee National Forest and Curlew National Grassland. A total of new 3189 voucher specimens were collected for this project in 2021 and 2022. To compile the annotated checklist, I consulted both newly collected specimens and specimen data from online botanical databases. A total of 1557 taxa (species, subspecies, varieties, and hybrids), 1423 species …

Annotation Of Non-Model Species’ Genomes, Taiya Jarva

Master's Theses

The innovations in high throughput sequencing technologies in recent decades has allowed unprecedented examination and characterization of the genetic make-up of both model and non-model species, which has led to a surge in the use of genomics in fields which were previously considered unfeasible. These advances have greatly expanded the realm of possibilities in the fields of ecology and conservation. It is now possible to the identification of large cohorts of genetic markers, including single nucleotide polymorphisms (SNPs) and larger structural variants, as well as signatures of selection and local adaptation. Markers can be used to identify species, define population …

The Impact Of Road Crossings On Karst Headwater Streams In Northwest Arkansas, Anthony M. Zenga

ATU Theses and Dissertations 2021 - Present

The karst region of NW Arkansas is home to many headwater endemic Species of Greatest Conservation Need (SGCN). This includes many species of darters, such as Etheostoma cragini, E. microperca, and E. mihileze, as well as crayfish such as Faxonious meeki brevis and F. nana. NW Arkansas is rapidly urbanizing, increasing the need to construct structures like culverts, bridges, and fords. These man-made road crossings can cause stream habitat degradation and fragmentation, as well as impair overall stream connectivity. To evaluate the impact that road crossings have on aquatic SGCN species and their habitat, 30 headwater streams were sampled throughout …

Sympatric Soil Microbe Interactions Between Streptomyces And Fusarium Isolates, Lehren A. Olk-Szost

All NMU Master's Theses

Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive …

Improving The Land Trust Model’S Impact On Environmental Conservation In Northern California, Peter Talbot

Master's Projects and Capstones

For years, the land trust sector of California and much of the United States has operated with a dollars and acres mentality that has prioritized fundraising as a result of acreage protected. Within California, nearly 5.8 million acres of land have been protected by 132 land trusts throughout the state. To accommodate for the diverse cross-section of land and the many needs of the population, land trusts take on numerous shapes and sizes. A unique aspect of this diversity is the rich agricultural and natural spaces found throughout the state. This mix of land and variety of land uses has …

The Miacomet Movement, Charles Duce

Masters Theses

Nantucket MA, is an island that has failed to refine and regulate the unreasonable uses of freshwater supply, and re-establish the purification processes involved with filtering our wastewater. The validity in claiming re-evaluation for Nantucket’s immoderacies in freshwater consumption and implausibility's in existing wastewater treatments, is seemingly irrefutable. Along with these detriments, Nantucket experiences harsh coastal erosion conditions that are rapidly altering beach profiles and diminishing irreplaceable habitats. Similarly, coastal flooding is causing ecological displacement and in some instances ecological degradation.

The relentlessness and fleetingness sparked by Nantucket’s climatic realities require willing and able action to mitigate impacts; but our …

Reintroducing Hemp (Rongony) In The Material Palette Of Madagascar: A Study On The Potential Of Hemp Clay Components And Its Impact On Social And Ecological Communities., Henintsoa Thierry Andrianambinina

Masters Theses

When mentioning the word hemp, especially in the local language of Madagascar, the literal translation does not set it apart from marijuana, as they are both called “rongony” - creating the stigma around hemp as the negative stereotype of marijuana. However, the material has been used by the ancestors of Madagascar, as well as across cultures, in its fibrous form to produce fabrication like textile goods and packaging. During colonization, the prohibition of hemp intensified, and since then, any activity related to either of these plants is prohibited and will end in severe punitive measures. This thesis explores the strengths …

On The Edge Of The "Er-Ocean" State, Mariesa Travers

Masters Theses

This thesis will explore how hard coastal infrastructure methods can be redesigned by softening the coastal edge to support the ecosystem and enhance public access to the beach. By referencing and arguing against techniques used by the U.S. Army Corps of Engineers (USACE) as a solution to deal with coastal erosion, this process will propose a regenerated design system. Through a series of material experiments, this research works with natural processes and flows, to create transitory systems that erode and ebb with the coast.

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata

Dissertations, Theses, and Capstone Projects

Freshwater fishes are extraordinarily diverse, considering their available habitats represent a tiny proportion of the earth’s surface. Rivers connect heterogeneous habitats in a linear form and provide excellent simplified models to understand how aquatic biodiversity evolves. In particular, the lower Congo River (LCR) in west Central Africa consists of a dynamic hydroscape exhibiting extraordinary aquatic biodiversity, endemicity, and morphological and ecological specialization. This system is thus an excellent natural laboratory for understanding complex speciation and population diversification processes. In my research, I explore various drivers of diversification, and adaptive evolution in rheophilic lamprologine cichlids endemic to the LCR, including Lamprologus …

The Influence Of Microorganisms On Human Health, Tiffany Bui

University Honors Theses

The purpose of this thesis is to explore the interplay between the environment, lifestyle, and composition of human microbiomes across different communities, with a specific focus on immune and digestive health. This literature review investigates three distinct types of communities: isolated/traditional, transitional, and urban/industrialized communities, each characterized by unique environments, societal structures, and interactions. These factors contribute to the distinct microbial populations and compositions within each community. It is impossible to avoid contact with microorganisms as they are present in every aspect of our lives, from the air we breathe, the water we drink, the soil we walk on, the …

Practical Solutions To The Invasion Of Lionfish In Utila, Honduras: Science, Education, Food, And Jewelry, Carolyn Corley

Undergraduate Honors Theses

Lionfish (Pterois sp.) are invasive species capable of devastating coral reef ecosystems due to their lack of predators, large appetites, generalist diet, high fecundity, and rapid spawning rates. As lionfish have expanded their distribution across the Caribbean, many conservation groups have taken it upon themselves to systematically remove these predators from environments where they are threatening native species. However, few have involved the community the way I observed while interning with the Whale Shark and Oceanic Research Center in Utila, Honduras. Protecting coral reefs is extremely important, especially in small communities like Utila, where the majority of people’s …

The Effects Of Urban Landscape, Soundscape, And Light Pollution On Avian Diversity And Nesting In South San Antonio, Texas, Alfredo Llamas

Masters Theses

As critical habitat continues to dwindle due to the expansion of urbanization, alternative habitat in urban ecosystems becomes a necessary natural resource for the survival of birds. In the last decade, local San Antonio environmental authorities have focused their efforts on restoring the San Antonio Mission Reach. Ecological revitalization of the San Antonio Mission Reach could increase avian, and flora biodiversity with ongoing restoration, yet how birds use restored habitat has not been assessed. Additionally, south of the Reach, two more peri-urban sites have great potential to be high quality habitat for birds but have not been surveyed for nesting …