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Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …

Trophic Ecology Of Black Swallowers (Scombriformes: Chiasmodontidae: Chiasmodon) In The Deep-Pelagic Gulf Of Mexico, Travis J. Kirk

All HCAS Student Capstones, Theses, and Dissertations

The ecology of deep-pelagic predatory fishes remains poorly understood despite their importance as ecosystem regulators and energy transfer vectors. This study investigated the trophic ecology of three species of the predatory fish genus Chiasmodon (“black swallowers”) in the Gulf of Mexico, a region that serves as an analog for the global low-latitude deep pelagial, the world’s largest cumulative ecosystem. Foraging habits (e.g., selectivity, chronology, daily ration) of an “advanced” evolutionary fish in a system that is otherwise dominated by basal fish taxa, were quantitatively estimated via high-resolution stomach content analysis. A quantitative dataset of both predator and prey abundance, the …

Cultivating Excellence: A Literature Review On Harnessing The Power Of The Gut Microbiome For Athletic Performance, Maya Katharine Dean

Honors Projects

The interplay between our gut microbiome and health is immense. This literature review analyzes the current research assessing the interplay between gut microbiome and athletic performance. Knowing how to improve gut microbial diversity via nutrition and supplementation can take athletic performance to the next level; namely improvements in immune, mental, and physical health.

Evaluating The Effectiveness Of Dormant Season Grazing To Reduce Cheatgrass And Its Effect On Biodiversity, Curtis L. Drake

Theses and Dissertations

Invasion of cheatgrass (Bromus tectorum L.) into sagebrush steppe communities threatens the survival of these at-risk ecosystems. One tool available to combat cheatgrass invasion is dormant season grazing. This study investigates the effectiveness of dormant season cattle grazing to reduce cheatgrass abundance in two high-elevation sagebrush steppe communities in southeastern Idaho, as well as the impact of dormant season grazing on plant species biodiversity. Our experiment utilized a randomized complete block design with four grazing treatments – ungrazed, fall-grazed, spring-grazed, and a combination of spring- and fall-grazed. We used an ANOVA standard least squares procedure to determine differences in biodiversity …

Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza

IGC Proceedings (1977-2023)

The nitrogen effects on Hyparrhenia diplandra were studied. Plants were grown on nutrient solutions of variable concentrations in nitrogen. The supplied nitrogen increased tillering, leaf production, lamina area, total dry matter accumulation and total nitrogen accumulation in lamina. A detailed examination showed that the effect on tillering was the main cause of the differences observed in dry weights between different treatments. The nitrogen supply elongated significantly the lamina and nitrogen deficiency increased its thickness; but this was not enough to compensate the loss of weight in lower nitrogen treatment. The lamina area as well as nitrogen accumulation in the lamina …

Movement Of Allelopathic Compound Coumarin From Plant Residue Of Sweet Vernalgrass (Anthoxanthum Odoratum L.) To Soil, Yoshito Yamamoto

IGC Proceedings (1977-2023)

This study investigated the movement of coumarin, an allelopathic compound, from the plant residue of sweet vernalgrass (Anthoxanthum odoratum L.) to soil, as well as the dynamics of coumarin in soil. The level of coumarin dissolved from sweet vernalgrass plant residue in both Andosols and Cambisols, which were watered every day, peaked on the 5th day after the beginning of watering, and fell gradually with each additional of day. Specifically, the coumarin content in Cambisols on the 5th day was 14.2 ppm, which is 4 times the coumarin level found in Andosols. The recovery percentage of coumarin extracted with …

Spatial Mapping Of The Benthic Community And How It Is Used To Research Effects Of Dredging In Louisiana's Lake Borgne., Meghan Johnson

LSU Master's Theses

Benthic communities are vitally important for healthy aquatic ecosystems across Louisiana’s coast. Specifically in Lake Borgne, ecologically important species of fish like the Gulf Sturgeon (Acipenser oxyrinchus desotoi) rely on benthic macrofauna as their main food source. The purpose of this study was to determine the spatial landscape of biodiversity and abundance of the benthic macrofauna community in Lake Borgne. Environmental conditions played a key role in community structure during the study period (fall 2021 through summer 2023) with a major drought occurring in 2023. In 2023, the decline in the abundance of most benthic invertebrates and in …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Vertebrate Diversity In The La Amistad International Park Buffer Zone, Guadalupe, Chiriqui, Panamá, Mina Olson

Independent Study Project (ISP) Collection

Forest fragmentation and increasing agricultural land use are posing threats to the diversity of vertebrates in Panama and across the Mesoamerican Biological Corridor. Protected areas are crucial for providing connectivity and maintaining vertebrate populations. For endemic species with small native ranges, these protected areas are critical for their survival due to sensitivity of habitat change. Higher species diversity and occupancy has been reported for both birds and mammals in protected and forested areas. This pilot survey of vertebrate species was conducted to determine which species live in a primary forest within the buffer zone of La Amistad International Park near …

Ecological Niche Modeling Of Endemic Texas Crayfish Species Under Current Conditions, Sarah A. Burgett

Biology Theses

Crayfish play many important roles in freshwater ecosystems such as ecosystem engineering, bioindicator, and food resource. Even though they are important to ecosystems, they are highly understudied. There has been previous work done on ecological niche modeling on Texas crayfish species, but this study takes it a step further by combining soil, climate, and hydrology variables to model the ecological niches of three endemic species: Procambarus texanus, Procambarus nueces, and Procambarus fayettei. Ecological niche models were created for the three species of interest using the program Maxent. I found that P. texanus and P. fayettei have indistinguishable …

Documenting The Southern Range Terminus Of The Wood Frog (Lithobates Sylvaticus) In North America, Christian Braswell

Theses

The Wood Frog (Lithobates sylvaticus) holds a remarkable position in North American amphibian biology, with its range extending from the Arctic Circle down to the near sub-tropical southeastern United States. This thesis presents a novel quantitative polymerase chain reaction analysis (qPCR) primer specific to L. sylvaticus and a survey effort regarding the southernmost distribution and detection of this species in Alabama through the application of environmental DNA (eDNA) sampling techniques. By investigating historical data and employing advanced genetic methodologies, this research provides insights into the contemporary status and distribution of the Wood Frog. This research is important to …

The Virginia Academy Of Science: A Scholarly Forum Over Decades For Students Of A Plant Ecologist, Stewart Ware

Virginia Journal of Science

As a newcomer to Virginia in 1968, I learned that annual meetings of the Virginia Academy of Science (VAS) were regarded as an excellent place for students to have their first experience giving a talk about their research to fellow scientists, and a place for faculty to get to know other Virginia scientists in their fields. Over the next four decades William and Mary students (undergraduate and graduate) and I were presenters or co-authors of 42 talks or posters at VAS annual meetings, 29 of them based on studies of plant ecology across Virginia. Two were talks by colleagues with …

Ecological Studies Of Wolves On Isle Royale, Sarah Hoy, Rolf O. Peterson, John Vucetich

Ecological Studies of Wolves on Isle Royale

Annual Report 2023-2024

Social And Behavior Factors Of Alzheimer's Disease And Related Dementias: A National Study In The Us, David Ciciora, Elizabeth Vásquez, Edward Valachovic, Lifang Hou, Yinan Zheng, Hua Xu, Xiaoqian Jiang, Kun Huang, Kelley Pettee Gabriel, Hong-Wen Deng, Mary P Gallant, Kai Zhang

Faculty, Staff and Student Publications

Introduction: Considerable research has linked many risk factors to Alzheimer's Disease and Related Dementias (ADRD). Without a clear etiology of ADRD, it is advantageous to rank the known risk factors by their importance and determine if disparities exist. Statistical-based ranking can provide insight into which risk factors should be further evaluated.

Methods: This observational, population-based study assessed 50 county-level measures and estimates related to ADRD in 3,155 counties in the U.S. using data from 2010 to 2021. Statistical analysis was performed in 2022-2023. The machine learning method, eXtreme Gradient Boosting, was utilized to rank the importance of these variables by …

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 …

An Ecological Analysis Of The Elevational Gradient Effect On Mushroom Community Diversity Near Andasibe, Madagascar, Zoe Garver

Independent Study Project (ISP) Collection

The effect of elevational gradients on biodiversity has been widely studied in the field of ecology (Rahbek, 1995). The evidence supports a trend for highest biodiversity at mid latitudes and decreasing biodiversity as elevation increases (Rahbek, 1997; Grytnes, 2003; Hariharan and Buckley, 2022). This effect has primarily been explained by variation of temperatures and resource availability at different elevations. However, the effect that elevation plays on fungal communities is relatively underrepresented in the literature (Dahlberg, 2001). This study analyzes changes in mushroom diversity across an elevational gradient in Mitsinjo Reserve and Analamazaotra National Park found in Madagascar. Using the Braun-Blanquet …

Phylogenomics Of Tetraopes Longhorn Beetles Unravels Their Evolutionary History And Biogeographic Origins, Nayeli Gutiérrez‑Trejo, Matthew H. Van Dam, Athena W. Lam, Gonzalo Martínez‑Herrera, Felipe A. Noguera, Thomas J. Weissling, Jessica L. Ware, Víctor H. Toledo‑Hernández, Frederick W. Skillman Jr., Brian D. Farrell, Oscar Pérez‑Flores, Lorenzo Prendini, James M. Carpenter

Department of Entomology: Faculty Publications

Tetraopes longhorn beetles are known for their resistance to milkweed plant toxins and their coevolutionary dynamics with milkweed plants (Asclepias). This association is considered a textbook example of coevolution, in which each species of Tetraopes is specialized to feed on one or a few species of Asclepias. A major challenge to investigating coevolutionary hypotheses and conducting molecular ecology studies lies in the limited understanding of the evolutionary history and biogeographical patterns of Tetraopes. By integrating genomic, morphological, paleontological, and geographical data, we present a robust phylogeny of Tetraopes and their relatives, using three inference methods with …

The Invasive Bank Vole (Clethrionomys Glareolus); A Longitudinal Investigation Into Rodents And Their Pathogen Communities, Using The Irish Rodent Invasion As A Model System., Andrew Mcmanus

Theses

The recent emergence of zoonotic pathogens such as, SARS-CoV-2, Ebola and Mpox, have emphasised the necessity to study wildlife and their pathogens. A knowledge gap currently exists in longitudinal studies of biological invasions, which are needed to understand the change in pathogen communities caused as the invader becomes more established. The invasion of Clethrionomys glareolus in Ireland provides a unique model system to study these changes at different stages of the bio-invasion. This is due to the depauperate small mammal community in Ireland, identifiable source population, introduction point, and ongoing expansion of C. glareolus in Ireland. Extensive work has been …

Bayesian Hierarchical Modelling Of Size Spectra, Jeff S. Wesner, Justin P.F. Pomeranz, James R. Junker, Vojsava Gjoni

Michigan Tech Publications

A fundamental pattern in ecology is that smaller organisms are more abundant than larger organisms. This pattern is known as the individual size distribution (ISD), which is the frequency distribution of all individual body sizes in an ecosystem. The ISD is described by a power law and a major goal of size spectra analyses is to estimate the exponent of the power law, λ. However, while numerous methods have been developed to do this, they have focused almost exclusively on estimating λ from single samples. Here, we develop an extension of the truncated Pareto distribution within the probabilistic modelling language …

A Biogeographical Appraisal Of The Threatened South East Africa Montane Archipelago Ecoregion, Julian Bayliss, Gabriela B Bittencourt-Silva, William R Branch, Carl Bruessow, Steve Collins, T Colin E Congdon, Werner Conradie, Michael Curran, Savel R Daniels, Iain Darbyshire, Harith Farooq, Lincoln Fishpool, Geoffrey Grantham, Zacharia Magombo, Hermenegildo Matimele, Ara Monadjem, Jose Monteiro, Jo Osborne, Justin Saunders, Paul Smith, Claire N Spottiswoode, Peter J Taylor, Jonathan Timberlake, Krystal A Tolley, Érica Tovela, Philip J Platts

Faculty, Staff and Student Publications

Recent biological surveys of ancient inselbergs in southern Malawi and northern Mozambique have led to the discovery and description of many species new to science, and overlapping centres of endemism across multiple taxa. Combining these endemic taxa with data on geology and climate, we propose the 'South East Africa Montane Archipelago' (SEAMA) as a distinct ecoregion of global biological importance. The ecoregion encompasses 30 granitic inselbergs reaching > 1000 m above sea level, hosting the largest (Mt Mabu) and smallest (Mt Lico) mid-elevation rainforests in southern Africa, as well as biologically unique montane grasslands. Endemic taxa include 127 plants, 45 vertebrates …

A Visual And Spatial Tool For Tracking, Mapping And Forecasting The Dispersal Of Biological Control Agents, Komi Mensah Agboka, John Odindi, Elfatih M. Abdel-Rahman, Onisimo Mutanga, Henri E.Z. Tonnang

All Peer-Reviewed Publications

iPydisp is an open-source, Python-based tool designed to model the spatio-temporal dispersal of insect species such as parasitoids. It provides an accessible interface for interactive spatio-temporal analysis, using cellular automata algorithms for easy data processing and updates. The tool's main features include intuitive data loading, easy setting of dispersal constraints, and dynamic visualization of dispersal patterns. iPydisp has the potential to improve our understanding of parasitoid dispersal and enhance pest management strategies.

Overview Of The Zoonotic Potential And Coinfection Of Sars-Cov-2 In Indonesia, Muhammad Khaliim Jati Kusala, Ni Luh Putu Indi Dharmayanti

Karbala International Journal of Modern Science

In the ASEAN region, Indonesia has the highest overall COVID-19 infection score. The SARS-CoV-2 pandemic first emerged in China and then transmitted sporadically throughout the world. Animals and humans can be infected with the corona virus, so this disease is classified as a zoonotic disease. This review aims to gather information regarding the potential of SARS-CoV-2 as a zoonotic disease and coinfections with several other pathogens in Indonesia. This study collected data demonstrating the potential for COVID-19 to be transmitted from humans to animals, as an evidenced by positive test results for the Bat Coronavirus Antigen in bats. Cats have …

Impacts Of Climate Change And Agricultural Practices On Nitrogen Processes, Genes, And Soil Nitrous Oxide Emissions: A Quantitative Review Of Meta-Analyses, Dafeng Hui, Avedananda Ray, Lovish Kasrija, Jaekedah Christian

Biology Faculty Research

Microbial-driven processes, including nitrification and denitrification closely related to soil nitrous oxide (N2O) production, are orchestrated by a network of enzymes and genes such as amoA genes from ammonia-oxidizing bacteria (AOB) and archaea (AOA), narG (nitrate reductase), nirS and nirK (nitrite reductase), and nosZ (N2O reductase). However, how climatic factors and agricultural practices could influence these genes and processes and, consequently, soil N2O emissions remain unclear. In this comprehensive review, we quantitatively assessed the effects of these factors on nitrogen processes and soil N2O emissions using mega-analysis (i.e., meta-meta-analysis). The results showed that global warming increased soil nitrification and denitrification …

Sulfur Assimilation Using Gaseous Carbonyl Sulfideby The Soil Fungus Trichoderma Harzianum, Ryuka Iizuka, Shohei Hattori, Yusuke Kosaka, Yoshihito Masaki, Yusuke Kawano, Iwao Ohtsu, David Hibbett, Yoko Katayama, Makoto Yoshida

Biology

Fungi have the capacity to assimilate a diverse range of both inorganic and organic sulfur compounds. It has been recognized that all sulfur sources taken up by fungi are in soluble forms. In this study, we present evidence that fungi can utilize gaseous carbonyl sulfide(COS) for the assimilation of a sulfur compound. We found that the filamentousfungus Trichoderma harzianum strain THIF08, which has constitutively high COS-degrading activity, was able to grow with COS as the sole sulfur source. Cultivation with 34S-labeled COS revealed that sulfur atom from COS was incorporated into intracellular metabolites such as glutathione and ergothioneine. COS degradation …

Schizachyrium Scoparium (C4) Better Tolerates Drought Than Andropogon Gerardii (C4) Via Constant Co2 Supply For Photosynthesis During Water Stress, Alina Dekirmenjian, Diego Montano, Michelle L. Budny, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Climate change is dramatically altering global precipitation patterns across terrestrial ecosystems, making it critically important that we understand both how and why plant species vary in their drought sensitivities. Andropogon gerardii and Schizachyrium scoparium, both C₄ grasses, provide a model system for understanding the physiological mechanisms that determine how species of a single functional type can differ in drought responses, an issue remains a critical gap in our ability to model and predict the impacts of drought on grassland ecosystems. Despite its greater lability of foliar water content, previous experiments have demonstrated that S. scoparium maintains higher photosynthetic …

Influence Of Microbes In Mediating Sorghum Resistance To Sugarcane Aphids, Edith Ikuze, Stephanie Cromwell, Paul A. Ayayee, Joe Louis

Department of Entomology: Faculty Publications

Gut microbiomes profoundly influence insect health and mediate interactions between plant hosts and their environments. Insects, including aphids, harbour diverse obligate symbionts that synthesize essential nutrients and facultative symbionts that enhance host fitness in specific ecological contexts. Sorghum (Sorghum bicolor) is a significant cereal crop cultivated worldwide that has been negatively affected by the presence of an invasive piercing-sucking insect pest, the sugarcane aphid (SCA; Melanaphis sacchari). We previously identified SC265 and SC1345 as the resistant and susceptible sorghum lines, respectively, among the founder nested association mapping (NAM) population. Here, using these resistant and susceptible lines, we …

Badger Ecology, Bovine Tuberculosis, And Population Management: Lessons From The Island Of Ireland, Andrew W. Byrne, Adrian Allen, Simone Ciuti, Eamonn Gormley, David J. Kelly, Nikki J. Marks, Nicola M. Marples, Fraser Menzies, Ian Montgomery, Chris Newman, Maria O’Hagan, Neil Reid, David M. Scantlebury, Peter Stuart, Ming-Shan Tsai

Publications

The European badger, Meles meles, is an important wildlife host for Mycobacterium bovis and contributes to the epidemiology of bovine tuberculosis (bTB) in cattle in several countries. The control of zoonotic diseases, such as bTB, is a central component of global One-Health strategies. Such strategies are complicated by human–wildlife conflicts, particularly where wildlife reservoirs are legally protected. The contrasting objectives of disease management and wildlife conservation, therefore, can require significant investment in research to support evidence-based policies. In Britain and Ireland, for example, badgers are a legally protected species but are also subject to lethal control and vaccination for …

On The Oviposition Of Homonota Aff. Darwinii In The Puna Region Of The Central Andes Of Argentina, Franco Valdez Ovallez, Rodrigo Gómez Alés, Rodrigo Nieva Cocilio, Tomás Martínez, Juan Carlos Acosta, José Villavicencio, Graciela Blanco

Turkish Journal of Zoology

Communal nest egg-laying refers to females laying their eggs with those of their conspecifics under or within artificial or natural structures. Homonota aff. darwinii is a recently discovered species that has not yet been formally described. The objective of this work is to characterise the oviposition of this species in the Puna region in the Central Andes of Argentina. We recorded the type and surface of the rocks where the eggs were laid, the temperature of the substrate, and the temperature of the rock surface facing the substrate. In addition, we recorded the daily temperature variation that a randomly selected …

A Comparative Study Of Biocrusts On Gypsum And Non-Gypsum Soils In The Northern Chihuahuan And Eastern Mojave Deserts, Usa: Biocrust Mosses Respond To Soil, Environmental, And Climatic Conditions, Katelyn Gobbie

Masters Theses

Biological soil crust communities (biocrusts) growing on gypsum soils have been well- documented for their prolific appearance and rich diversity of lichens and bryophytes. However, studies characterizing gypsum biocrusts have primarily occurred outside of the U.S., most of which lack comparisons to other soil types. We conducted intensive field surveys to evaluate the cover and frequency of biocrust functional groups and moss species on gypsum and non-gypsum soils in the U.S. regions with the most extensive gypsum outcrops, the northern Chihuahuan and eastern Mojave Deserts. We employed canonical correspondence analysis (CCA) to relate the observed differences in biocrust abundance and …

High Thermal Quality Rookeries Facilitate High Thermoregulatory Accuracy In Pregnant Female Rattlesnakes, Haley A. Moniz, Jack Henry Buck, Hayley L. Crowell, Scott M. Goetz, Trevor D. Ruiz, Emily N. Taylor, Scott M. Bobacks

United States Department of Agriculture Wildlife Services: Staff Publications

Temperature is a primary factor influencing organismal development, and the fluctuating daily and seasonal thermal regimes of temperate climates may challenge the ability of viviparous reptiles to optimize body temperatures during gestation. Testing how viviparous reptiles navigate highly variable thermal conditions (e.g., relatively cold nights and/or highly fluctuating temperatures) is a powerful way to understand how they use microhabitats for thermoregulatory benefits. We assessed the thermal ecology of pregnant and non-pregnant female prairie rattlesnakes (Crotalus viridis) inhabiting a high-elevation, montane shrubland in northwest Colorado throughout their short summer active season, addressing the thermal consequences of microhabitat selection with …