Ecology and Evolutionary Biology Commons^™

Drivers Of Post-Fire Vascular Plant Regeneration In The Conifer-Dominated Boreal Forest Of Southern Northwest Territories, Alison White

Theses and Dissertations (Comprehensive)

In recent years, climate warming has led to an increase in the severity and frequency of naturally occurring fires in boreal ecosystems globally. In 2014, an unprecedented 3.4 million hectares of boreal forest burned in the Northwest Territories (NWT). While much research has focused on post-fire succession of serotinous tree species such as Picea mariana (black spruce) and Pinus banksiana (jack pine), the understory community of vascular plants play an important role in ecosystem functioning but less is known about the response of this component of the system to changing fire regimes. Regeneration strategies such as the ability to resprout …

Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine

Theses and Dissertations (Comprehensive)

Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …

Salt Retention In Wetland Soils And Effects On Dissolved Organic Carbon Export, Kayla Marie Mcguire

Master's Theses and Doctoral Dissertations

Deicing salt runoff has negative effects on ecosystems. Wetland ecosystems can act as important filters for runoff pollution (e.g., nutrients), mitigating damage to plants and microbes. Wetlands are important sinks for nutrients and pollutants (e.g., road salt) and transformation spots for many nutrients including carbon. The interactions between deicing salt runoff and wetland soil carbon were explored by measuring chloride export and retention, dissolved organic carbon (DOC) export, and carbon quality using mesocosm experiments. Net retention of Cl- was highest in soils receiving high salt treatments (5.0 g/L NaCl), although percent retention of Cl- was greater in soils receiving moderate …

Characterizing The Complex Relationship Between The Brown Widow Spider And Its Bacterial Endosymbiont, Wolbachia, Emily Knight

Electronic Theses and Dissertations

The brown widow spider, Latrodectus geometricus (C. L. Koch 1841), has been found to harbor the maternally inherited bacterial endosymbiont Wolbachia pipientis (Hertig and Wolbach 1924), but endosymbiont infection frequency varies widely among Southeastern US populations. Wolbachia is known to manipulate the reproduction of its hosts through male feminization, parthenogenesis, male killing, and cytoplasmic incompatibility. In brown widows, Wolbachia does not alter sex ratios, but any other effects the symbiont has on the spider are unknown. In my first chapter, I assess if there is linkage between Wolbachia infection and maternally inherited mitochondrial DNA (mtDNA) in three brown widow populations. …

Migratory Patterns And Population Genetic Structure In A Declining Wetland-Dependent Songbird, Matthew G. Desaix

Theses and Dissertations

Understanding migratory connectivity is essential for assessing the drivers behind population dynamics and for implementing effective management in migratory species. Genetic markers provide a means to describe migratory connectivity, as well as incorporate population genetic analyses, however genetic markers can be uninformative for species with weak genetic structure. In this study, we evaluate range-wide population genetic structure and migratory connectivity in the prothonotary warbler, Protonotaria citrea, a wetland-dependent neotropical migratory songbird, using high-resolution genetic markers. We reveal regional genetic structure between sampling sites in the Mississippi River Valley and the Atlantic Seaboard with overall weak genetic differentiation among populations …

Identification Of Taxonomic And Functional Ichthyofaunal Zones Within The James River Basin, Virginia, Joseph L. Noel

Theses and Dissertations

Environmental gradients structure ichthyofaunal communities longitudinally along river networks via the selective filtering of species’ traits. In many instances, these environmental influences have created distinct zones of co-occurring fish species. Zonation studies have most often been conducted with taxonomic data (species x site matrices), but the increasing availability of functional trait data creates an opportunity to build more rigorous understanding of species’ co-occurrence patterns. Notably, zonation studies that use taxonomic data may not reveal the same patterns as studies based on trait data. In this study, we tested for distinct ichthyofaunal zonation in James River Basin, VA using a combination …

The Role Of Vegetation-Topographic Interactions In A Barrier Island System: Island Migration In A Changing Climate, Benjamin Nettleton

Theses and Dissertations

Islands have been characterized based on vegetation and topography as exhibiting different disturbance regimes - reinforcing or resisting. This study had two objectives: quantify barrier island upland migration and vegetation cover change over 32 years (1984-2016), and assess tolerance of two prevalent dune grass species, A. breviligulata, and S. patens to sand burial. Using Landsat imagery from the Virginia Coast Reserve, islands were categorized within the disturbance resistance/reinforcing framework based on dune elevation. Resistant areas were associated with woody cover and low marsh to upland migration while reinforcing areas had low vegetation cover and high rates of migration. System-wide, …

Floral Symmetry Genes Elucidate The Development And Evolution Of Oil-Bee Pollinated Flowers Of Malpighiaceae And Krameriaceae, Farahnoz N. Khojayori

Theses and Dissertations

Specialization on insect and animal pollinators is thought to be the driving force for the evolution of floral traits. Specifically in the New World (NW), the oil-bee pollination syndrome has led to the convergence of floral characters in two distantly related families of core eudicots, Malpighiaceae and Krameriaceae. Both families display a flag-like structure that establishes a zygomorphic flower and floral oil rewards in epithelial elaiophores. These traits work concomitantly to attract and reward female oil-bees that help fertilize these flowers and in return receive oils. The underlying genetics of floral zygomorphy were studied in several clades of core eudicots, …

Red-Headed Woodpecker Full Annual Cycle Ecology At Fort A.P. Hill, Virginia, Benjamin Nickley

Theses and Dissertations

The red-headed woodpecker is a primary cavity excavator found throughout the Eastern Deciduous Forest and parts of the Great Plains. Although widespread, the red-headed woodpecker is generally considered uncommon, with patchily distributed populations. Over the past 50 years, this species has experienced precipitous, range-wide declines. The red-headed woodpecker uses a variety of cover types to meet resource needs across the annual cycle, ranging from oak savannas and wetlands, to mature beech forests and urban parks. Given their apparent adaptability to such a wide range of habitats, causes of declines are perplexing. To understand and stem declines, recent studies have focused …

Forest Structural Complexity And Net Primary Production Resilience Across A Gradient Of Disturbance In A Great Lakes Ecosystem, Lisa T. Haber

Theses and Dissertations

Forests are an important component of the global carbon (C) cycle and contribute to climate change mitigation through atmospheric C uptake and storage in biomass and soils. However, the forest C sink is susceptible to disturbance, which modifies physical and biological structure and limits spatial extent of forests. Unlike severe, stand-replacing disturbances that reset forest successional trajectories and may simplify ecosystem structure, moderate severity disturbances may instead introduce complexity in ways that sustain net primary production (NPP), leading to the phenomenon of “NPP resilience.” In this study, we examined the linkage between disturbance severity and ecosystem biological and physical structural …

Climate Change And Mountaintop Removal Mining: A Maxent Assessment Of The Potential Dual Threat To West Virginia Fishes, Lindsey R F Hendrick

Theses and Dissertations

Accounts of species’ range shifts in response to climate change, most often as latitudinal shifts towards the poles or upslope shifts to higher elevations, are rapidly accumulating. These range shifts are often attributed to species ‘tracking’ their thermal niches as temperatures in their native ranges increase. Our objective was to estimate the degree to which climate change-driven shifts in water temperature may increase the exposure of West Virginia’s native freshwater fishes to mountaintop removal surface coal mining. Mid-century shifts in habitat suitability for nine non-game West Virginia fishes were projected via Maximum Entropy species distribution modeling, using a combination of …

Evolving Reproductive Isolation In The Parasitic Wasp Genus Cotesia, Justin P. Bredlau

Theses and Dissertations

Parasitic wasps are highly diverse and play a major role in suppression of herbivorous pest populations, but relatively little is known of the mechanisms driving their diversity. Molecular studies indicate that cryptic species complexes resulting from adaptations to specific hosts or host-foodplants may be common. The gregarious endoparasitoid, Cotesia congregata (Braconidae), is a model system for understanding parasitic wasp biology. It is reported to attack at least 15 species of sphingid caterpillars, most of which are plant family specialists. Molecular studies have demonstrated genetic differentiation of two host-foodplant complex sources originating from Manduca sexta on tobacco (MsT) and Ceratomia catalpae …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

The Effect Of Self-Recognition In The Competition Between Genets Of Solidago Altissima, Charles Jaques

Masters Theses

Competition is a major driving force in the abundance, distribution, and diversity within any biological system. Plants are more likely to suffer reductions in fitness as a consequence of competition, as they typically occur in dense communities. Individuals within these populations must respond to both inter- and intraspecific competition. Recent studies suggest that the ability to distinguish kin from non-kin may play an integral role in the success of individuals within different plant populations and communities. However, a less known interaction is that between individual clones within a genet as they grow, spread, and begin to interact with nearby rival …

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …

Polar Gigantism And Sea Spiders: A Study Of Respiratory Scaling, Steven Joseph Lane

Graduate Student Theses, Dissertations, & Professional Papers

All animals must breathe to survive. The types of primary respiratory structures vary across the metazoa, and the overall size and components of these structures scale with body size. The scaling of respiratory structures has been well studied in vertebrate lungs and gills, but very few, if any studies, have looked at it in terms of cutaneous gas exchange, the process where oxygen moves across the outer integument via diffusion. My dissertation has sought to fill this gap in knowledge by studying animals that use cutaneous respiration, and my work has determined both how the components of their respiratory surfaces …

Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre

Graduate Student Theses, Dissertations, & Professional Papers

Grassland and shrubland songbird species are a guild of conservation concern in North America. Many of these species have experienced severe population declines, due to habitat loss and land use change. This makes the conservation and management of remaining habitat of crucial importance for this guild. Grazing by large herbivores is an ecosystem process in grassland systems, and in North America, one of the major historic grazers was the Plains bison (Bison bison). Bison are considered ecosystem engineers, because they modify habitat to be more or less suitable for other species, such as grassland and shrubland songbirds. Bison …

Bottom-Up And Top-Down Controls On Food Webs In Headwater Streams, Miriam O. Bayer

Graduate Student Theses, Dissertations, & Professional Papers

Headwater streams account for 70% of stream channel length in the USA and are important as hotspots of nutrient uptake and native biodiversity. Biofilm, the mixed auto- and heterotrophic microbial community covering stream substrates, is where the majority of nutrient processing occurs, and forms the base of stream food webs, particularly in heavily shaded, oligotrophic streams. Both bottom-up (e.g., nutrients, light) and top-down (i.e., consumption) processes are known to affect periphyton, the autotrophic component of biofilm, but little is known about what controls the biofilm community as a whole. Top-down effects are common in streams, where fish are often the …

Impact Of Giant Miscanthus (Miscanthus X Giganteus) Cultivation On Midwestern Farmland Birds, Matthew Craffey

Masters Theses

Giant Miscanthus (Miscanthus x giganteus) is a promising bioenergy feedstock, newly introduced to North America. However, the qualities that make Giant Miscanthus an attractive bioenergy feedstock may pose challenges to local wildlife. To assess the impacts of Giant Miscanthus on Midwestern farmland birds, I conducted point count and vegetation surveys at three sites in east-central Illinois where Giant Miscanthus was being cultivated. I used occupancy modeling to assess the relative influence of Giant Miscanthus on five species relative to other habitat and landscape characteristics. Dickcissel (Spiza Americana), Eastern Meadowlark (Sturnella magna), and Red-Winged Blackbird …

Impact Of Temperature Increase On Freshwater Fish Species: Energetics And Muscle Mechanics Of Two Centrarchids, Israt Jahan

Masters Theses

Fishes have evolved physiologically to live within a specific range of environmental variation and existence outside of that range can be stressful or fatal. These ranges can coincide for fishes that evolved in similar habitats. This study investigates physiological processes limiting thermal tolerance, specifically how changes in water temperature affect the swimming energetics and muscle mechanics in largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus). I focused on the impact of temperature change at the muscle level in these two species and the capacity to adapt to rapid changes in the environment. Fish were housed at …

Near-Surface Permafrost Ground Ice Characteristics And Ecological And Physical Drivers Of Transient Layer Ice Content In Discontinuous Permafrost, Jason Paul

Theses and Dissertations (Comprehensive)

Accelerated climate warming in northern regions is causing permafrost degradation, leading to the reduction of the areal extent of permafrost. Permafrost is the foundation for many northern ecosystems and communities, so its thaw can have important ecological and societal consequences. Thaw of ice-rich permafrost can cause subsidence of the ground surface proportional to excess ice content. Terrain settlement can cause ponding or damage to infrastructure. Following a surface disturbance that removes much of the vegetation cover, a shift in the ground thermal regime can cause an increase in active layer thickness and rapid thaw of the top portion of permafrost. …

Environmental Factors Affecting Hatch Success In The Loggerhead Sea Turtle (Caretta Caretta), Mattie J. Whitesell

Electronic Theses and Dissertations

The loggerhead turtle (Caretta caretta) is a species federally listed as “threatened” whose global populations are declining. Georgia Department of Natural Resources conservation protocols for this species require the daily monitoring of nesting activity and permit physical relocation of nests which are at risk of being eroded or flooded by storms and high tides in order to increase hatch success--the proportion of hatched to unhatched eggs. Relocated nests are moved to an area with higher elevation in order to avoid flooding, but other variables such as increased temperature and decreased moisture are introduced when relocating. For years temperature …

Foraging Ecology Of A Winter Bird Community In Southeastern Georgia, Rachel E. Mowbray

Electronic Theses and Dissertations

Classical views on community structure emphasized deterministic processes and the importance of competition in shaping communities. However, the processes responsible for shaping avian communities remain controversial. Attempts to understand distributions and abundances of species are complicated by the fact that birds are highly mobile. Many species migrate biannually between summer breeding grounds and wintering grounds. The goal of this study was to test four hypotheses that attempt to explain how migratory species integrate into resident assemblages of birds (Empty-Niche Hypothesis, Competitive-Exclusion Hypothesis, Niche-Partitioning Hypothesis, and Generalist-Migrant Hypothesis). I collected data on birds foraging during the winter of 2017-2018 in Magnolia …

Altered Spring Phenology Of North American Freshwater Turtles And The Importance Of Representative Populations, Fredric J. Janzen, Luke A. Hoekstra, Ronald J. Brooks, David M. Carroll, J Whitfield Gibbons, Judith L. Greene, John B. Iverson, Jacqueline D. Litzgus, Edwin D. Michael, Steven G. Parren, Willem M. Roosenburg, Gabriel F. Strain, John K. Tucker, Gordon R. Ultsch

Faculty & Staff Scholarship

Globally, populations of diverse taxa have altered phenology in response to climate change. However, most research has focused on a single population of a given taxon, which may be unrepresentative for comparative analyses, and few long-term studies of phenology in ectothermic amniotes have been published. We test for climate- altered phenology using long-term studies (10–36 years) of nesting behavior in 14 populations representing six genera of freshwater turtles (Chelydra, Chrysemys, Kinosternon, Malaclemys, Sternotherus, and Trachemys). Nesting season initiation oc- curs earlier in more recent years, with 11 of the populations advancing phenology. The onset of nesting for nearly all populations …

Paleoparasitology And Pathoecology In Russia: Investigations And Perspectives, Sergey Slepchenko, Karl Reinhard

Karl Reinhard Publications

Russia, both as the USSR and the Russian federation, provided a source of parasitological theory for decades. A key figure in Russian parasitology was Yevgeny Pavlovsky. He developed the nidus concept, the conceptual basis for the field of pathoecology. He also coined the term “paleoparasitology.” Pathoecology is a foundation concept in archaeological parasitology. Paleoparasitology, as defined by Pavlovsky, is an avenue for understanding of host parasite evolution over very long time periods. These contributions are not fully recognized internationally. Similarly, the long history of Russian paleontological and archaeological investigations are not fully known. Most recently, discoveries from archaeological sites show …

Taphonomic Considerations On Pinworm Prevalence In Three Ancestral Puebloan Latrines, Morgana Camacho, Alena M. Iñiguez, Karl Reinhard

Karl Reinhard Publications

For archaeological studies it is always necessary to consider taphonomic factors that could have influenced in ancient material preservation. Parasite eggs are usually highly degraded in ancient sites dated from all periods of time and taphonomic factors are mentioned to explain absence and low quantity of eggs found. In this study, we compare parasite egg recovery of three Great House latrines: two from Aztec Ruins (Rooms 219 and 225) and one from Salmon Ruins. We compared through statistical regression the recovery of eggs with the abundance of two classes of decomposers: mites and nematodes. These microorganisms have relation with nematode …

The Paleoepidemiology Of Enterobius Vermicularis (Nemata: Oxyuridae) Among The Loma San Gabriel At La Cueva De Los Muertos Chiquitos (600–800 Ce), Rio Zape Valley, Durango, Mexico, Johnica J. Morrow, Karl Reinhard

Karl Reinhard Publications

One hundred coprolites excavated from La Cueva de los Muertos Chiquitos (600–800 CE) in the Rio Zape Valley of present-day Durango, Mexico, were examined for the presence of helminth eggs utilizing standard archaeoparasitological techniques. Eggs of the human pinworm (Enterobius vermicularis) were recovered from 34 of the 100 coprolites examined. Eggs of parasites were photographed and measured before egg concentration values were calculated for each positive sample. Egg concentration values demonstrated an overdispersed pattern of distribution among the samples (66% uninfected, 25% less than 100 eggs/g, 8% between 100 and 500 eggs/g, and 1% more than 500 eggs/g). …

Autologous Bone Flap Resorption Years After Subtemporal Craniotomy, John Oladapo Obafunwa, Emily E. Hammerl, David Jaskierny, Livia A. Taylor, Lynette Russell, Karl Reinhard

Karl Reinhard Publications

In Spring of 2012, the partially undressed and skeletonized remains of a homeless adult Hispanic male was found in a fairly open wooded area in Nebraska. The remains showed evidence of extensive pathologies, which included healed traumas and surgeries. Examination of the decedent's medical records revealed that he had a history of kidney and liver problems, alcohol abuse, several traumas including a major head injury that necessitated a craniotomy, and radiological features of neurocysticercosis. The autologous bone flap, which was replaced after the craniotomy, had resorbed significantly away from the edges of the injury. Death was variously attributed to craniocerebral …

New Evidence Of Ancient Parasitism Among Late Archaic And Ancestral Puebloan Residents Of Chaco Canyon, Rachel E. Paseka, Carrie C. Heitman, Karl Reinhard

Karl Reinhard Publications

Archaeoparasitology provides a unique perspective on the health and habits of ancient cultures through the identification of parasite remains in archaeological materials. We identified eggs of the human whipworm, Trichuris trichiura, in coprolites recovered from Late Archaic (1926–1751 cal. BCE) and Ancestral Puebloan (1039–1163 cal. CE) sites in Chaco Canyon, New Mexico. Our findings represent the earliest record of T. trichiura in North America, the first record of the species from Chaco Canyon, and the first record of a macroparasite from a Late Archaic site (Atlatl Cave) on the Colorado Plateau. T. trichiura is common in the …

Diversity And Phylogenetic Relationships Of European Species Of Crepidostomum Braun, 1900 (Trematoda: Allocreadiidae) Based On Rdna, With Special Reference To Crepidostomum Oschmarini Zhokhov & Pugacheva, 1998, Romualda Petkevičiūtė, Virmantas Stunžėnas, Alexander E. Zhokhov, Larisa G. Poddubnaya, Gražina Stanevičiūtė

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Background

Within the genus Crepidostomum Braun, 1900, identification of species and taxonomic decisions made only on the basis of adult morphology have resulted in great problems associated with evaluating actual diversity and validity of species. Life cycle data, while equal in importance to adult characters, are scarce, controversial or incomplete for most Crepidostomum spp. In this study, rDNA sequences generated from adult and larval Crepidostomum spp. and some other allocreadiid species were analyzed to reveal the diversity and phylogenetic relationships of the species and their host range. Detailed morphological description based on light microscopy, SEM tegumental surface topography and genetic …