Ecology and Evolutionary Biology Commons^™

Hybridization Between The Rare Gray-Headed Chickadee And The Abundant Boreal Chickadee In The Midst Of Shifting Climate, Matthew R. Armstrong

School of Natural Resources: Dissertations, Theses, and Student Research

As species respond to changing climate, distributions and abundances may shift and alter species interactions. Hybridization, a relatively widespread phenomenon becoming more common with climate change, can have beneficial and detrimental effects on population growth rates and genetic integrity. Beneficial effects due to the introduction of advantageous alleles and increased genetic diversity may result from hybridization. Species may also accrue fitness costs associated with changing climates if mismatches occur between environmental variables and phenotypes. The gray-headed chickadee, Poecile cinctus lathami, is an extremely rare songbird that has experienced marked declines in recent decades within its restricted distribution in Alaska …

New Insights On Hybridization In Potamogeton Floridanus (The Florida Pondweed), Kaitlyn R. Sampson

Graduate Theses and Dissertations (2019 - present)

Freshwater ecosystems are some of the most important and highest threatened habitats in the world, and aquatic plants play an important, but often-overlooked, role in maintaining them. Potamogeton is a diverse and ecologically important aquatic plant genus well known for taxonomic difficulty and rampant hybridization. lbis study aimed to 1) test the hypothesis that Potamogeton jloridanus (Florida pondweed) is a hybrid between P. oakesianus and P. pulcher, and 2) to investigate correlations in ecological conditions for the focal species. This study revealed the discovery of a new population of P. jloridanus in Big Coldwater Creek in Santa Rosa Co., FL, …

The Ecological Applications Of Δ17O: Validating A Novel Technique For Assessing Animal Metabolism And Water Intake, Zachary Taylor Steele

Biological Sciences Theses & Dissertations

Animals obtain water via different processes such as drinking, consuming food, and through metabolic processes like at the end of the electron transport chain when atmospheric oxygen is combined with hydrogen to form ‘cytochrome oxidase water’. Assessing animal water flux and metabolism has mainly been conducted via stable isotope analysis (SIA) of biological samples using hydrogen (²H) and oxygen isotopes (¹⁶O, ¹⁷O, and ¹⁸O; Δ¹⁷O), typically using enriched isotope tracers. However, natural abundance isotope modeling offers an approach for conducting SIA of biological samples that differs because it relies on the unique, …

Estimating Increased Transient Water Storage With Increases In Beaver Dam Activity, Konrad Hafen, Joseph M. Wheaton, Brett B. Roper, Philip Bailey, William W. Macfarlane, Bethany T. Neilson, Christopher J. Tennant

Watershed Sciences Faculty Publications

Dam building by beaver (Castor spp.) slows water movement through montane valleys, increasing transient water storage and the diversity of residence times. In some cases, water storage created by beaver dam construction is correlated to changes in streamflow magnitude and timing. However, the total amount of additional surface and groundwater storage that beaver dams may create (and, thus, their maximum potential impact on streamflow) has not been contextualized in the water balance of larger river basins. We estimate the potential transient water storage increases that could be created at 5, 25, 50, and 100% of maximum modeled beaver dam capacity …

From Pixels To Plants: Remote Sensing Of California Invasive Plants, Kenneth Rangel

Master's Projects and Capstones

Invasive plants cause significant impacts to ecosystems, the economy, and human health. California has experienced significant plant invasions and is well suited to future invasion because of its Mediterranean climate and human disturbance. Eradication or control of invasive plant species requires a detailed understanding of their spatial distribution, which typically involves on the ground surveys that can be expensive or inconsistent. Remote sensing offers a potential alternative or supplement to in-person invasive plant mapping. This study performed a comparative analysis of 41 remote sensing studies that mapped the distribution of California invasive plants. I found that while high spectral resolution …

Agroecology And Soil Stewardship: Values And Techniques Of Smallholder Farmers In Bernalillo County, Stephanie Olivas

Geography ETDs

Agrarian movements around the world use agroecology to build sovereignty and steward dynamic ecosystems. Research has shown that agroecological farmers steward more resilient crops, more resilient soil biomes, and greater biodiversity than conventional agriculture. GIS and remote sensing offer many tools to detect the impacts of these farmers on the environment, but it is less clear how such technologies fit into agroecological goals. This study asks: what values, experiences and knowledge do smallholder producers in Bernalillo County embody in their soil stewardship practices? Also, what experience or knowledge do smallholder producers in Bernalillo County have about remote sensing, and would …

Surface Water Quality Assessment Of Mingo Creek County Park: The Impacts Of Extractive Industries, Mikayla J. Bayto

Electronic Theses and Dissertations

Historical and current extraction operations and infrastructure, including natural gas pipelines, conventional and unconventional oil and natural gas drilling, longwall coal mining, and strip coal mining, occur throughout the Mingo Creek watershed of Washington County, Pennsylvania, including Mingo Creek County Park. Mingo Creek and several associated tributaries flow through Mingo Creek County Park, eventually discharging into the Monongahela River. An independent water quality study was conducted from June 2020 through July 2023 in Mingo Creek County Park to determine if historical and current extraction activities impact Mingo Creek and its associated tributaries. Weekly sampling of Mingo Creek and associated tributaries …

Sheep Grazing Influences The Abundance, Diversity, And Community Composition Of Wild Bees And Other Insects In Livestock Pastures, Roshani Sharma Acharya, Timothy B. Leslie, Joan Burke, Kusum Naithani, Emily Fitting, Kelly Loftin, Neelendra K. Joshi

Entomology and Plant Pathology Faculty Publications and Presentations

Pollinators contribute to the establishment of perennial native forages, but little is known about the effect of grazing practices on pollinator abundance and diversity in livestock pasture ecosystems. Grazing reduces floral resources available to bees and other insects, and as a result, may influence their communities. The main objective of this study was to examine the impact of sheep grazing on bees and other non-bee insects in livestock pasture established with seed mixes of native forb/legume/grass and warm season grasses. Each pasture was divided into two halves (in a split-plot design) using an electric fence in which one plot was …

Do Heat Waves Drive Natural Selection In Damselflies?, Adam Baranyk

Biological Sciences Undergraduate Honors Theses

Climate change has led to changes in both mean temperatures and temperature extremes over the recent years. These changes have had differential effects on animals throughout the world. Ectotherms depend on their external environment for thermal regulation, making them especially susceptible to temperature extremes. It is not yet clear whether there is a relationship between physical traits in ectotherms, and survivorship throughout a heat wave. That is, whether or not temperature extremes driven survival selection. In this study, a heat wave was simulated artificially using thermally regulated mesocosms at different temperatures (18°C, 22° C, 26° C, 30° C) with a …

Evaluating Novel Approaches For Improving Anadromous Fish Passage In Coastal Rivers, Aaron Bunch

All Dissertations

Few of the world's rivers remain free-flowing for over 1000 km, significantly impacting anadromous fish populations due to dam-induced habitat fragmentation. Three partial migration barriers (low-head dams) on North Carolina's Cape Fear River (USA)—lock and dam 1 (LD1), lock and dam 2 (LD2), and lock and dam 3 (LD3)—impact American shad Alosa sapidissima, Atlantic sturgeon Acipenser oxyrinchus oxyrinchus, and striped bass Morone saxatilis populations. Mitigation strategies to pass fish upstream have included conservation locking, nature-like fishway construction, and environmental flows (e-flows). This study introduced a novel e-flow (dam submergence flow), tested acoustic double-tagging techniques for tracking American …

Reconnecting With Nature One Classroom At A Time, Bianca Apuzzo

Senior Honors Projects

Environmental science is more important to today’s society than it has ever been, and developing basic ecoliteracy is the easiest way we can work towards a more sustainable future. Ecoliteracy allows us to connect deeper to nature and provides us with the information needed to protect and restore our beautiful planet. We are rolling downhill, picking up speed as we go, through a silent mass extinction. The scariest part of it all: nobody seems to care.

In response to the lack of environmental education provided to today’s students, I have created a syllabus for a high school level science course …

Plant-Plant Interaction In Early- Vs. Late-Successional Varieties Of The Hawaiian Landscape-Dominant Tree, Metrosideros Polymorpha, Tomoko Sakishima

UNLV Theses, Dissertations, Professional Papers, and Capstones

Plant-plant interactions play an important role in assembling plant communities. Interactions between neighboring plants can vary as a result of the genetic relatedness of neighbors, impacting rates of growth and patterns of resource allocation. When growing alongside close relatives, some species decrease their growth in a form of cooperation, while others grow faster through facilitation. A complication of plant interaction studies arises because decreased growth in the presence of close relatives can also be due to competition for resources, which increases with phenotypic similarity. Further complicating matters, mycorrhizal fungi, through their connections with plant roots, may strongly influence plant interactions. …

Seasonal Climate And Environmental Conditions Associated With Physiological Variations Of Southwestern United States Pines, Taylor Brewer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Juvenile and adult conifers in the southwestern United States are vulnerable to a range of different abiotic and biotic factors, yet it is unclear how their stress tolerance varies across environments. Predicted increases in the frequency and intensity of disturbance as well as greater climate and weather variability across the region highlight the potential for differential physiological responses across tree species and populations. This thesis focuses on two physiologic mechanisms, hydraulic vulnerability and mortality, that could be altered by climate change in two broadly distributed southwestern United States conifers: ponderosa pine and pinyon pine.

In chapter 2, I measured the …

High Intraspecific Diversity Of Pocillopora Damicornis In Southeast Asia Reflects Adaptive Potential To Climate Change, Maria Lucille Carr

Theses and Dissertations

Marine heatwaves are increasing in intensity and frequency because of increased emissions of greenhouse gases. On coral reefs, warmer temperatures cause coral bleaching, mortality, and shifts in benthic composition. However, coral bleaching responses and survival vary geographically. Several hypotheses may explain such geographical differences in thermal tolerance, including the possibility that some localities may support higher intraspecific diversity than other localities, increasing the likelihood of survival of some individuals through heatwaves. Here we assessed geographic patterns of intraspecific genetic diversity in the ubiquitous coral Pocillopora damicornis. Intraspecific genetic diversity was assessed for 428 sequences across 44 sites in the Pacific …

Net Fluxes Of Broadband Shortwave And Photosynthetically Active Radiation Complement Ndvi And Near Infrared Reflectance Of Vegetation To Explain Gross Photosynthesis Variability Across Ecosystems And Climate, Kanishka Mallick, Joseph Verfaillie, Tianxin Wang, Ariane Arias Ortiz, Daphne Szutu, Koong Yi, Yanghui Kang, Robert Shortt, Tian Hu, Mauro Sulis, Zoltan Szantoi, Gilles Boulet, Joshua B. Fisher, Dennis Baldocchi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A significant challenge in global change research is understanding how vegetation interacts with the environment to influence ecosystem gross primary productivity (GPP) through carbon assimilation. One emerging objective is to consistently predict GPP fluctuations worldwide by establishing a robust scaling relationship between GPP measured at flux towers and satellite spectral reflectance data. However, a major hurdle in achieving this goal is the discrepancy in spatial resolution between early satellite measurements and eddy flux measurements. By using a large set of growing season data covering 100 site-years in North and Central America, we explored the potential of transforming incident and reflected …

Rescape: Transforming Coral-Reefscape Images For Quantitative Analysis, Zachary Ferris, Eraldo Ribeiro, Tomofumi Nagata, Robert Van Woesik

Ocean Engineering and Marine Sciences Faculty Publications

Ever since the first image of a coral reef was captured in 1885, people worldwide have been accumulating images of coral reefscapes that document the historic conditions of reefs. However, these innumerable reefscape images suffer from perspective distortion, which reduces the apparent size of distant taxa, rendering the images unusable for quantitative analysis of reef conditions. Here we solve this century-long distortion problem by developing a novel computer-vision algorithm, ReScape, which removes the perspective distortion from reefscape images by transforming them into top-down views, making them usable for quantitative analysis of reef conditions. In doing so, we demonstrate the …

Genomic Population Structure Of Great Hammerhead Sharks (Sphyrna Mokarran) Across The Indo-Pacific, Naomi L. Brunjes, Samuel M. Williams, Alexis L. Levengood, Matt K. Broadhurst, Vincent Raoult, Alastair V. Harry, Matias Braccini, Madeline E. Green, Julia L. Y. Spaet, Michael J. Travers, Bonnie J. Holmes

Fisheries Research Articles

Context

Currently, little information exists describing the population structure of great hammerhead sharks (Sphyrna mokarran) in Australian waters. Aims

This study used single nucleotide polymorphisms to investigate fine-scale population structure in S. mokarran across the Indo-Pacific. Methods

DNA was extracted from 235 individuals across six Australian locations and a Red Sea outgroup. Population parameters were calculated and visualised to test structuring across locations. Key results

No fine-scale population structuring was observed for S. mokarran across the Indo-Pacific. However, population structuring occurred for all Australian locations when compared to the Red Sea outgroup. Conclusions

Findings suggest a single stock …

Predicting The Potential Distribution Of Pseudococcus Longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) In South Korea Using A Climex Model, Su Bin Kim, Soo-Jung Suh

Insecta Mundi

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) is a widely-distributed pest that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of this mealybug pest in South Korea remains a primary concern because of its high incidence of interceptions screened during inspection. Hence, this species prompted a modelling effort to assess its potential risk of introduction. Potential risk maps were developed for this pest with a CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 …

Socioecological Assessment Of Birds In Ngezi-Vumawimbi Nature Forest Reserve, Eli Taub

Independent Study Project (ISP) Collection

Effective management of natural resources requires consideration of the environment through both a physical and a sociological lens. In this study, the birds in Ngezi-Vumawimbi Nature Forest Reserve were examined through both a biological mist-net survey and a socioecological series of interviews with people living in the surrounding villages. The mist-net survey compared the understory species in undisturbed and disturbed area of the forest, as well as analyzing birds caught for biologically meaningful information on subspecies and sexual dimorphism. While the mist-net survey was largely unsuccessful, highlighting the need for alternative bird capture methods in Ngezi, it found a decrease …

Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn

Earth and Environmental Sciences Faculty Publications

Strophomenoid brachiopods had thin, concavo-convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter-fed in a concave-upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore-clogging mud. The paradox is that epi- biont distributions on strophomenoids support a convex-upward life position, as do studies of strophome- noid stability and trace fossils formed by strophomenoid sediment-clearing. A premise of the concave-upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vul- nerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial …

Avian Diversity And Abundance Among Agricultural Land, Forested Land, And Their Ecotone In Guadalupe, Cerro Punta, Chiriquí Province, Republic Of Panamá., Stella Rae Kinard

Independent Study Project (ISP) Collection

As the human population increases, finding the balance between modifying land use for resources and protecting areas to preserve species that are threatened by anthropogenic disturbance is an ever growing problem. Guadalupe is a town in the Western Highlands of Panamá that struggles in this balance as its primary income source is agriculture, but it is located on the border of two protected areas, Parque Nacional La Amistad and Parque Nacional Volcán Barú. By understanding the unique ways in which avifauna utilize distinct vegetative landscapes, recommendations can be made for management styles of farms in Guadalupe to implement practices that …

Vascular Epiphyte Population Dynamics Within Human-Modified Landscapes Of Guadalupe, Cerro Punta, Chiriquí, Panamá, Lucine Tashjian

Independent Study Project (ISP) Collection

Epiphytes are plants that grow on other plants non-parasitically, and globally, epiphytes compose a very large and diverse group. They are especially abundant and species-rich in the tropics- particularly, in tropical montane forest ecosystems. Human population growth in the tropics, however, has resulted in significant declines in forest cover with land being converted largely for agricultural purposes. Studies on epiphytes have traditionally been undertaken in pristine, undisturbed forest ecosystems, yet terrestrial land conversion has increased the need to understand the value of human-modified ecosystems for epiphytic populations and biodiversity conservation. This study sought to understand the relationship between human modification …

The Role Of Geomorphological Context In Vegetative Succession Within The Breiðamerkurjökull Glacial Foreland, Lucas Nerbonne

Independent Study Project (ISP) Collection

As glaciers retreat worldwide at an accelerating pace, understanding primary succession in these newly exposed landscapes becomes increasingly critical. This study examines the initial vegetative colonization patterns in glacial forelands, focusing on the influence of geomorphological formations of resulting plant communities. By analyzing vegetative communities in glaciofluvial and push moraine deposits, this study highlights how the more varied, channelized morphologies of fluvial deposits create potential microclimates better conducive to heterogenous plant colonization than the homogenous terrain of the nearby push moraine. Vegetative coverage, sediment size, and species abundance was collected at 480 sites across 6 different historical glacial extents across …

Demographic Consequences Of Off-River Nesting For Piping Plover (Charadrius Melodus) And Interior Least Tern (Sternula Antillarum Athalassos) In The Lower Platte River System, Nebraska, Elsa M. Forsberg

School of Natural Resources: Dissertations, Theses, and Student Research

Piping plovers (Charadrius melodus; hereafter, plovers) and interior least terns (Sternula antillarum athalassos; hereafter, terns) are two avian species that nest along the Lower Platte River system (LPRS) in Nebraska. In the LPRS, river sandbars provide natural nesting habitat, but off-river sites provide substantial nesting habitat especially when sandbar habitat is scarce. Although presumed to be important for the persistence of plovers and terns, off-river habitat is not self-sustaining and predicted to decline. Understanding the vital rates of plovers and terns in the LPRS will inform the role of off- river sites in the future conservation …

Feasibility Study Of Coral Farming In Southwest Madagascar: In-Situ And Ex-Situ Approaches, Raquel Reis

Independent Study Project (ISP) Collection

The southwest coast of Madagascar is home to hundreds of miles of coral reefs that for decades have been susceptible to intense degradation due to anthropogenic influences on marine environments. For reasons involving economic opportunity, conservation strategies, human health safeguarding and advancements to coral research, coral aquaculture in the Toliara region presents an opportunity to restore quality of life and the environment. Other countries in the west Indian ocean have seen great success in coral aquaculture; however, Madagascar, despite having ideal natural circumstances, has not deeply explored coral aquaculture. This review presents an investigation into the feasibility of coral farming, …

Assessing The Impacts Of Anthropogenic Activities On Coral Reef Health In Ushongo, Tanzania Using Coral Diversity And Parrotfish Abundance As Indicators, Thao Mai

Independent Study Project (ISP) Collection

Coral reefs, covering two-thirds of our oceans, are vital and diverse ecosystems, earning them the nickname of “rainforests of the sea”. Despite occupying only 1% of the ocean’s floor, they support 25% of all marine species, providing shelter, nursery ground and food, all the while also protecting the coast and providing job opportunities for local communities. Considered keystone species, coral reefs are highly sensitive to disturbances caused by pollution, climate change, but also anthropogenic activities such as coastal development, destructive fishing practices and tourism, endangering their existence and the entire marine ecosystem. Parrotfish, a crucial resident of these ecosystems, often …

Early Report Of A Microcosm Of The Fourth Major Global Bleaching Event: A Comprehensive Survey Of Coral Bleaching At Chumbe Island Coral Park, Zanzibar, Christian Boudreaux

Independent Study Project (ISP) Collection

Coral reefs harbor a wealth of the biodiversity present in the ocean. They provide an array of ecological and economic services that make them crucial to the function of a healthy ocean and prosperous coastal communities. Due to an array of anthropogenic stressors, including an increase in ocean temperatures as a result of climate change, reefs have been devastated worldwide. This is, in large part, due to the process of coral bleaching, the expelling of symbiont algae which the coral needs to produce energy, for an extended period until death. This study surveyed bleaching and death at a deeper and …

A Study Of Anthropogenic Impacts On Echinoderms In The Jambiani Intertidal Area, Zanzibar, Amaury O. Halley

Independent Study Project (ISP) Collection

The coastal region of Jambiani, Unguja, hosts a rich diversity of marine life within its extensive intertidal zones. Despite its ecological significance, this area is increasingly exposed to anthropogenic disturbances due to increased human activities. This study examines the impacts of these disturbances on the biodiversity, zonation, and species abundance of echinoderms in the intertidal habitats of Jambiani. Through a comprehensive field study involving fifteen transects and detailed substrate analysis, the project evaluated the distribution and abundance of echinoderm species and assessed the influence of human activities such as seaweed farming, anchor damage, and beach trampling on these communities. The …

Anuran Diversity And Abundance Across Two Sites With Varying Levels Of Light Pollution In El Valle De Antón, Coclé, Panamá, Jackson Dray

Independent Study Project (ISP) Collection

The impact of artificial light at night (ALAN) on anuran populations has been a subject of growing concern in ecological research. Anurans are particularly susceptible to the impacts of artificial light due to their nocturnal nature and an extensive exposure throughout various stages of life histories. Exposure to artificial light has been shown to impact the larval development and reproductive behavior of anurans. The impacts on anurans juvenile populations suggest a relationship between light pollution and anuran abundance. This study aimed to investigate the hypothesis that ALAN negatively affects the abundance and diversity of anurans. Field surveys were conducted in …

Variations In Salinity And Forest Structure Between Marginal And Cloistered Mangrove Forests In Boca Del Drago, Bocas Del Toro, Panama, Mary Elizabeth Hodge

Independent Study Project (ISP) Collection

Mangroves are incredibly important ecosystems that have an outsized impact on their surroundings, providing crucial ecosystem services like carbon sequestration and coastal protection. At the same time, mangroves are some of the most threatened habitats due to their valuable position along tropical coastlines. Globally, mangrove forests are deforested and degraded by aquaculture, tourism developments, urbanization, and overharvesting. Due to high rates of mangrove loss, mangrove deforestation is now illegal in Panama, though this legislation is inconsistent and allows for exceptions, especially in tourism developments. This study aims to probe the impacts of localized coastal developments on a small mangrove forest …