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Full-Text Articles in Life Sciences

Where Are All Of Arkansas' Chinquapins? An Ecological Assessment Of Castanea Throughout The State, Logan Pierce Estes Dec 2018

Where Are All Of Arkansas' Chinquapins? An Ecological Assessment Of Castanea Throughout The State, Logan Pierce Estes

Theses and Dissertations

Around the turn of the twentieth-century, the chestnut blight fungus (Cryphonectria parasitica) was accidentally introduced into North America. This strong pathogen, which specializes on trees of the genus Castanea, spread rapidly and within half a century had nearly extirpated North America’s Castanea natives from their ranges. During this catastrophe, the American chestnut (Castanea dentata) garnered much of the scientific attention, pushing the other Castanea natives – the chinquapins – to the wayside. More than a century following the spread of the blight, little research into the ecology of North America’s chinquapins had been performed, leaving these trees significantly underrepresented. The ...


Fall Migration And Winter Habitat Use Of Northern Saw-Whet Owls (Aegolius Acadicus) In The Ozark Highlands, Mitchell L. Pruitt Dec 2018

Fall Migration And Winter Habitat Use Of Northern Saw-Whet Owls (Aegolius Acadicus) In The Ozark Highlands, Mitchell L. Pruitt

Theses and Dissertations

Studying movement ecology is important not only in understanding the distribution of a species, but in understanding the magnitude of migration through certain regions, as well as explaining regional differences in demographics. The Northern Saw-whet Owl (Aegolius acadicus) is a small, migratory forest owl found throughout much of North America. Despite being captured widely during fall migration, the species’ movement ecology is poorly understood. Exploratory studies outside the saw-whet owl’s normal range have successfully captured the species during fall migration. In the Ozark Highlands ecoregion of the central United States, their status has been considered vagrant during fall and ...


Impacts Of Natural And Anthropogenic Colonized Habitats On The Range Shifting Mangrove Tree Crab (Aratus Pisonii), Zachary John Cannizzo Oct 2018

Impacts Of Natural And Anthropogenic Colonized Habitats On The Range Shifting Mangrove Tree Crab (Aratus Pisonii), Zachary John Cannizzo

Theses and Dissertations

Mis-matches in climate-mediated shifting rates cause the ranges of some species to become decoupled from their historic ecosystem, leading to the colonization of ecosystems they have not previously inhabited. When this occurs, the shifting species may experience suboptimal conditions which challenge its ability to persist and expand into the novel ecosystem. However, within the colonized ecosystem, shifting species may encounter artificial habitat analogues: artificial habitats that more closely resemble the species’ historic ecosystem than the surrounding habitat and which mitigate some of the negative impacts experienced elsewhere in the novel ecosystem. Despite their importance to the ecology, life history, and ...


Modified Landscapes, Esther Nooner May 2018

Modified Landscapes, Esther Nooner

Theses and Dissertations

Modified Landscapes is a body of work that reflects serious thought regarding Nature and its future. My personal experience and beliefs are at the core of why I believe this subject to be of great importance and why it will sustain many artists’ investigations for the time to come. The influences that informed this process are explored through experiences I had traveling, reading and exploring the photograph as a material object. The manipulation of the photograph is meant to question the beautiful, untouched scene and break the Romantic gaze that is historically tied to representations of Nature and insist upon ...


A Hemimysis Driven Novel Ecosystem At A Modified Boulder Breakwall, Eric John Geisthardt Aug 2017

A Hemimysis Driven Novel Ecosystem At A Modified Boulder Breakwall, Eric John Geisthardt

Theses and Dissertations

The US Army Corps of Engineers (USACE) is mandated to maintain and repair aging breakwall structures in all commercial ports on the Great Lakes. In May of 2014, the construction of Milwaukee Harbor USACE “green” breakwall (GBW) reconciliation created complex rocky aquatic habitat by depositing cobble-sized stone as a veneer over standard 6-10 ton boulders, thus creating “control” (boulder) and “treatment” (cobble) habitats. The breakwall is home to a prolific population of Hemimysis anomala, the introduced Ponto-Caspian mysid, which is significantly more abundant on cobble versus boulders (p<0.05, using a novel trap for Hemimysis). Fish and forage communities were sampled in 2015 and 2016 using a combination of experimental and micromesh gill nets, night scuba diving surveys, and a novel Hemimysis trap. This nearshore lithophilic mysid appears to provide a significant new seasonal food resource in the Milwaukee Harbor for pelagic prey fishes during inshore spawning migrations and upwelling events. Alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) fed heavily on Hemimysis with some individuals consuming hundreds of mysids. Night scuba diving surveys and gill netting confirmed that rainbow smelt preferred to forage on the cobble section (p<0.05), and also consumed more Hemimysis there than they did at the control breakwall site (p<0.05). Hemimysis were also the primary food item consumed by nearshore game fishes such as YOY yellow perch (Perca flavescens), YOY largemouth bass (Micropterus salmoides), and juvenile rock bass (Ambloplites rupestris) caught at the breakwall. This study provides the first documented evidence that where abundant in the Laurentian Great Lakes, Hemimysis do have the ability to significantly impact local food webs and drive the feeding ecology of both pelagic transient and nearshore resident fishes.


The Effects Of Disturbance And Species Specific Interactions On Diversity In An Agent Based Forest Simulation, Matthew E. Mills Jan 2017

The Effects Of Disturbance And Species Specific Interactions On Diversity In An Agent Based Forest Simulation, Matthew E. Mills

Theses and Dissertations

In ecology literature, there is much data which suggests that conspecific negative density dependence (CNDD) and abiotic disturbances increase biodiversity in forests. This thesis elucidates the notion that not only do these two forces increase diversity, but they may also interact with one another in order to achieve higher levels of biodiversity. Abiotic disturbances, like fires and hurricanes, can indirectly impact conspecific effects because when these forces remove individuals from the landscape, the role of the conspecific effects will change. The interaction of these two factors in biodiversity are explored in an agent based forest simulation through a resource surface ...


Mechanisms Of Native Shrub Encroachment On A Virginia Barrier Island, Joseph Thompson Jan 2016

Mechanisms Of Native Shrub Encroachment On A Virginia Barrier Island, Joseph Thompson

Theses and Dissertations

Species composition, temperature, soil nutrients, and leaf area index (LAI) were recorded across three encroaching Morella cerifera thicket edges and three free- standing shrubs on Hog Island, Virginia to characterize the effect of shrub thickets on the plant community and microclimate. Electron transport rate (ETR) was taken on shrub leaves to determine if microclimate benefits M. cerifera physiology. Species richness was lowest inside shrub thickets. Soil water content and LAI were higher in shrub thickets compared to grassland. Soil organic matter, N, and C were higher inside shrub thickets. Summer and fall maximum temperatures were more moderate in shrub thickets ...


Dispersal: A Multidisciplinary Investigation Of Plant Life, Alexandra E. Arzt Jan 2015

Dispersal: A Multidisciplinary Investigation Of Plant Life, Alexandra E. Arzt

Theses and Dissertations

Using plants as a basis for exploring the interstices between the human and nonhuman, this thesis investigates ideas of awareness, intelligence, deep time, animism, and the fluctuating human perception of the agency of Nature. It outlines environmental art practices since the 1950s involving vegetal life. In addition, the paper provides a critical analysis of plant perception of Jakob von Uexküll’s work and theories of vital materialism and “critical plant studies” while noting recent studies in plant neurobiology. In my work, plants become active participants via their movement, seeding, and smell. This study takes the form of imitation, purposeful symbiosis ...


Population Genetics, Distributions And Phenology Of Bombus Latreille, 1802 And Xylocopa Latreille, 1802 (Hymenoptera: Apidae), Amber Dawn Tripodi Dec 2014

Population Genetics, Distributions And Phenology Of Bombus Latreille, 1802 And Xylocopa Latreille, 1802 (Hymenoptera: Apidae), Amber Dawn Tripodi

Theses and Dissertations

This work addresses multiple knowledge gaps in bee ecology, population health and phylogeography in order to provide insights into the changing distributions of native bees. A comparison of Arkansas bumble bee records mirrors range-wide surveys, with records of stable species (Bombus bimaculatus Cresson, 1863 and B. impatiens Cresson, 1863) increasing three-fold, and records of the declining B. pensylvanicus (DeGeer, 1773) dropping to 60% of historical levels. However, nationally-recommended conservation-genetics tools did not mirror these results on a regional level. Stable and declining species had equivalent genetic diversity in samples from Arkansas and Tennessee (HS range: 0.46-0.63). Diploid ...


Facing The Wreck: Death, Optimism, And The Fragmented Form, Rachael Marie Schaffner Aug 2014

Facing The Wreck: Death, Optimism, And The Fragmented Form, Rachael Marie Schaffner

Theses and Dissertations

Walter Benjamin described history as a winged angel who faces backwards, staring perpetually into the past as the violent winds of destiny carry him into the future (Illuminations). Despite a western, post-enlightenment myth of eternal progress, the wreckage of human contributions to history is clearly evident in our 21st-century understanding of anthropogenic impact on global ecology. In the context of these ecological crises (and the resulting political and economic questions), postmodern novels reveal a powerful ability to imagine different ways of living and interacting with the world. This thesis traces the relationship between fragmentation, death, and liminal experiences through Frederick ...


Ecology, Phylogenetics, And Conservation Of Draba Asterophora Complex: A Rare, Alpine, Endemic From Lake Tahoe, Usa, Emily Ruth Smith Putnam Dec 2013

Ecology, Phylogenetics, And Conservation Of Draba Asterophora Complex: A Rare, Alpine, Endemic From Lake Tahoe, Usa, Emily Ruth Smith Putnam

Theses and Dissertations

Rare, alpine, endemic species are particularly at risk for extinction. Alpine environments are especially vulnerable to climate change and human impacts, such as ski resort development and snowmaking. Draba asterophora Payson is a rare, alpine species that occurs only in three disjunct mountain-top regions surrounding Lake Tahoe. It is currently threatened by human impacts, such as ski resorts, as well as indirect influences of climate change and therefore in need of better understanding for conservation purposes. Draba asterophora may be able to serve as a case study for other similarly vulnerable, rare, alpine, endemic species with conservation needs. We utilized ...


Environmental Regulation Of Tidal Wetland Microbial Communities And Associated Biogeochemistry, Ember Morrissey Dec 2013

Environmental Regulation Of Tidal Wetland Microbial Communities And Associated Biogeochemistry, Ember Morrissey

Theses and Dissertations

Microbial communities play an essential role in carrying out the biogeochemical cycles that sustain life on Earth, yet we know very little about their ecology. One question of particular interest is how environmental conditions shape microbial community structure (i.e., the types of organisms found in the community and their relative abundance), and whether such changes in structure are related to biogeochemical function. It is the aim of this dissertation to address this question via the examination of carbon (C) and nitrogen (N) cycling in wetland ecosystems, which due to their diverse hydrology have a profound influence on biogeochemical cycles ...


Effect Of Prescribed Burning In The Forests Of Buffalo National River, Arkansas, Francis Ndar Onduso Dec 2013

Effect Of Prescribed Burning In The Forests Of Buffalo National River, Arkansas, Francis Ndar Onduso

Theses and Dissertations

Prescribed burning (also referred to as controlled or hazard reduction burning) refers to the use of fire under controlled conditions to achieve a desired end product or goal. However, the nature and magnitude of the changes that result from prescribed burning are still incompletely known, and this is especially true for the forests of the Ozarks of northern Arkansas. The overall objective of the research project described herein was to obtain the data necessary to develop a better understanding of these changes, particularly as they relate to the use of prescribed burning as a management technique in the Buffalo National ...


Modeling Approaches, Physiological Responses, And Climate Change: How Good Is "Good Enough?", Nicole Kish Jan 2013

Modeling Approaches, Physiological Responses, And Climate Change: How Good Is "Good Enough?", Nicole Kish

Theses and Dissertations

Predicting spatial and temporal patterns in the responses of organisms and ecosystems to climate change has emerged as a major focus of macrophysiological research, with much work centered on the impacts of temperature. A potential difficulty lies in the observation that measures of 'habitat' such as air, land and sea surface temperature often differ greatly from the body temperature actually experienced by organisms, as the latter drives reproduction and survival. As a result, it is unclear how often these simple measurements of habitat are 'good enough' for predicting physiological stress in the field, and when more complicated methods are needed ...


Freshwater Phytoplankton Populations Detected Using High Pressure Liquid Chromatography (Hplc) Of Taxon-Specific Pigments, Lauren Jeanne Simmons Dec 2012

Freshwater Phytoplankton Populations Detected Using High Pressure Liquid Chromatography (Hplc) Of Taxon-Specific Pigments, Lauren Jeanne Simmons

Theses and Dissertations

Phytoplankton are key primary producers in aquatic ecosystems, and the principle food source for primary consumers. Individual phytoplankton species respond to different physical, chemical and biological parameters, so monitoring taxonomic composition of the phytoplankton community is a means to monitor changes in environmental conditions. Phytoplankton community changes have frequently been monitored by estimating biomass (using chlorophyll a, measured fluorometrically), and taxonomic data obtained from cell counts. While such methods are useful, they are time-consuming. I hypothesized that high pressure liquid chromatography (HPLC) methods, which have been frequently used in marine systems, would allow separation and identification of key pigments. These ...


A Reexamination Of The Eastern Collared Lizard (Crotaphytus Collaris Collaris) In Arkansas, Ashley A. Grimsley Aug 2012

A Reexamination Of The Eastern Collared Lizard (Crotaphytus Collaris Collaris) In Arkansas, Ashley A. Grimsley

Theses and Dissertations

Loss of suitable habitat is a threat to species worldwide. Habitat destruction, including loss, change, and fragmentation of habitat, is the leading cause of species extinction. Eastern collared lizards (Crotaphytus collaris collaris) are habitat specialists on glades. Both C. c. collaris and glade habitats are rare and of special concern in the state of Arkansas. Many glade populations have already been extirpated in the Ozarks of Arkansas and Missouri. Increasing knowledge of the distribution, habitat structure, and population dynamics of C. c. collaris is important to ensure the survival of this species in Arkansas.

A literature review of the C ...


Changes In Leaf Morphology, Photosynthesis And Nitrogen Content In Two Coastal Shrubs, Elizabeth Kost May 2011

Changes In Leaf Morphology, Photosynthesis And Nitrogen Content In Two Coastal Shrubs, Elizabeth Kost

Theses and Dissertations

It is important to understand mechanisms that facilitate expansion of two common shrubs, Morella cerifera and Baccharis halimifolia in coastal environments. The purpose of my study was to investigate the physiological and structural changes that occur as leaves age. Photosynthesis, incident light, chlorophyll, and leaf C:N ratios were quantified for young, intermediate, and old leaves (distal, central and proximal leaves, respectively). Leaf structural differences were also compared. Leaves did not change morphologically with age. Light decreased with leaf age and during winter months. Photosynthesis showed no seasonal or age related patterns. Chlorophyll increased initially and then declined with age ...


Developmental Contributions To Variation In Aspen Clones And The Influence Of Pre-Fire Succession Status On Aspen Regeneration Success, Eric A. Smith Jul 2010

Developmental Contributions To Variation In Aspen Clones And The Influence Of Pre-Fire Succession Status On Aspen Regeneration Success, Eric A. Smith

Theses and Dissertations

This thesis includes two studies: The first examined developmental changes that take place in the physiology of aspen (Populus tremuloides Michx.) and to characterize developmental influences on patterns of phenotypic trait variation among different aged ramets within the aspen clones. We surveyed eight clones, each with 8 distinct age classes ranging from 1 to 170 yrs in age. Using regression analysis we examined the relationships between ramet age and expression of functional phenotypes. Eight of the phenotypic traits demonstrated a non-linear relationship in which large changes in phenotype occurred in the early stages of ramet development and stabilized thereafter. Water ...


Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer Mar 2007

Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer

Theses and Dissertations

Science means “to know", a process for gaining knowledge and an understanding of the natural world. Students need to be involved in active learning. In other words, they must do science, not just hear about it. Good science encourages students to gain knowledge by doing science: observing, questioning, exploring, making and testing hypotheses, comparing predictions, evaluating data, and communicating conclusions. This unit plan is designed to incorporate the components of fresh water, ecology, water quality, and a class-wide science project. Each lesson addresses selected standards from the state core curriculum and has specific objectives that are tied to the learning ...


Spatial And Temporal Patterns Of Anadromous Fish Passage At Boshers Dam Vertical Slot Fishway On The James River, Richmond, Virginia, Matthew Thomas Fisher Jan 2007

Spatial And Temporal Patterns Of Anadromous Fish Passage At Boshers Dam Vertical Slot Fishway On The James River, Richmond, Virginia, Matthew Thomas Fisher

Theses and Dissertations

Boshers dam vertical slot fishway, James River, Virginia, U.S.A., opened in 1999 and restored connectivity to 543.3 km of spawning habitat for anadromous fish. The fishway also allowed local movement of resident species. Video observation from 2001-2005 was used to evaluate environmental predictors of American shad (Alosa sapidissima) and sea lamprey (Petromyzon marinus) passage. The ecological effects of restoring connectivity to upstream habitat for gizzard shad (Dorosoma cepedianum) and blue catfish (Ictalurus furcatus) are also discussed. Regression analysis determined that the best predictor of increased daytime American shad passage is higher water temperatures and discharge and for ...


Ecological Investigations Of Chukars In Western Utah, Randy T. Larsen Jul 2006

Ecological Investigations Of Chukars In Western Utah, Randy T. Larsen

Theses and Dissertations

This thesis presents three separate manuscripts in chapter format dealing with the ecology of Chukars (Alectoris chukar) in western North America. All three manuscripts have been formatted for publication in professional journals. Chapter one confirms discovery of ingested lead pellets in Chukars across a broad region of western Utah including all four western counties sampled. Prevalence rates were 1.9% (n=105) for crops and 10.7% (n=75) of gizzards showing no evidence of penetration wounds. Ingestion is likely related to grit size preferences that are consistent with common shot sizes. The second chapter describes watering patterns and water-site ...


Genetic Assessment Of Rare Blackbanded Sunfish (Enneacanthus Chaetodon) Populations In Virginia, Diana Marie Kercher Jan 2006

Genetic Assessment Of Rare Blackbanded Sunfish (Enneacanthus Chaetodon) Populations In Virginia, Diana Marie Kercher

Theses and Dissertations

Enneacanthus chaetodon, the blackbanded sunfish, has become increasingly rare throughout its distribution in the Eastern United States. In Virginia, E. chaetodon maintains an endangered status and individuals persist in six populations. Mitochondrial DNA (mtDNA) and microsatellite data were assessed to determine the genetic characters and gene diversity of the Virginia populations. The results of these analyses were then compared to five additional populations; four from New Jersey and one from North Carolina that were known to have relatively good fitness and were not impacted severely by habitat alteration. The results of this study are relevant to selection of proper management ...


Density Effects On Growth, Survival And Diet Of June Sucker (Chasmistes Liorus): A Component Allee Effect In An Endangered Species., David Barrett Gonzalez Nov 2004

Density Effects On Growth, Survival And Diet Of June Sucker (Chasmistes Liorus): A Component Allee Effect In An Endangered Species., David Barrett Gonzalez

Theses and Dissertations

Density-dependence is considered one of the most important regulators of population growth, and it has been documented across a wide variety of species. Typically, population growth rate and components thereof decline with increasing density (i.e., negative density-dependence); however, in species that exhibit high population densities and social behavior, positive density-dependence (i.e., Allee effect) may occur at low density. June sucker, a federally endangered lake sucker endemic to Utah Lake, Utah, USA, occurred historically at high density, and it exhibits coordinated feeding behavior. These characteristics indicate a potential for the existence of an Allee effect at current low population ...


The Effects Of Habitat Fragmentation On Amorpha Canescens, A Prairie Forb, And Its Associated Herbivores, Cassandra Kasun Lewis Jul 1999

The Effects Of Habitat Fragmentation On Amorpha Canescens, A Prairie Forb, And Its Associated Herbivores, Cassandra Kasun Lewis

Theses and Dissertations

No abstract provided.