Life Sciences Commons^™

The Interaction Between Predation And Sound Pollution On The Internal And External Microbiome Of The Grasshoppers Melanopus Sanguinipes, Alanna Bond

Theses and Dissertations

Anthropogenic activities such as construction and agriculture directly affect its surrounding environments. Many studies have focused on how megafauna and flora are impacted by human activities, however, relatively little is known how new occupation of land affects smaller organisms such as insects and microbes. Additionally, other stressors such as predation can impact host physiology. The grasshopper species Melanopussanguinipes was chosen to be used in a study to measure how stress caused by artificial sound and predation can alter exoskeleton and gut microbiomes once exposed to these stressors.

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones

Theses and Dissertations

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …

Quantifying Aboveground Biomass In A Tropical Forest Using A Lidar Waveform Weighted Allometric Model, Alejandro Rojas

Theses and Dissertations

Our knowledge of the distribution and amount of terrestrial above ground biomass (AGB) has increased using lidar technology. Recent advancements in satellite lidar has enabled global mapping of forest biomass and structure. However, there are large biases in satellite lidar estimates which impacts our understanding of carbon dynamics, particularly in tropical forests.

Ni-Meister et al. (2022) developed a lidar full waveform weighted height-based allometric model which produced very good results in temperate deciduous/conifer forest in the continental US. The purpose of this study was to evaluate this biomass model in an African tropical forest using the Land Vegetation and Ice …

Understanding The Genomic Influence And Virulence Capabilities Of Environmentally Isolated Vibrios, Shannon Elizabeth Pipes

Theses and Dissertations

The genus Vibrio consists of Gram-negative bacteria that possess a curved rod shape and are routinely isolated from estuarine and coastal salt water. Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus are the major three species that contribute to human disease worldwide, and a variety of other Vibrio species contribute to persistent problems in the aquaculture and fishing industries. The CDC estimates that vibrios cause 80,000 cases of disease each year in the United States alone, however, this number is thought to be underestimated, since some disease is only self-limiting, meaning patients may not seek medical treatment and have …

Microbial Communities Hosted By Carnivorous Pitcher Plants: Diversity, Recruitment, Functions And Succession In Sarracenia Purpurea Microbiomes, Jacob Jeffrey Grothjan

Theses and Dissertations

The pitcher plant Sarracenia purpurea supplements nutrient acquisition through carnivory, capturing insect prey which are digested by a food web community of eukaryotes and bacteria. Analysis of both bacterial and eukaryotic diversity, and an understanding of bacterial recruitment into pitchers and succession of bacterial and eukaryotic communities over time have not been well explored. This thesis presents three studies designed to address these gaps using field sampling and manipulative greenhouse experiments. Study I compared bacterial and eukaryotic composition and diversity of pitcher communities within and between populations of plants in two distinct wetland habitats. Genetic sequence analysis revealed an underappreciated …

Characterizing The Temporal And Spatial Distribution Of The Cannonball Jellyfish (Stomolophus Meleagris) In The South Atlantic Bight, Lauren G. Faulk

Theses and Dissertations

The cannonball jellyfish, Stomolophus meleagris, is commercially harvested throughout its range in the tropical and sub-tropical Americas, including in the South Atlantic Bight, where an estimated 4,000 tons (less than 2.4% of the estimated stock in South Carolina during the spring) are harvested annually. Like many Scyphozoan jellyfish, cannonball jellies have high interannual variability and little is known about the environmental drivers of their distribution and phenology. To better understand the ecology of this targeted species, we used fisheries-independent abundance data of cannonball jellyfish from 2001 to 2019 collected by the Southeast Area Monitoring and Assessment Program (SEAMAP) throughout the …

Evaluating The Multi-Level Community Effects Of Root Hemiparasites In Northern Illinois, Anna Marie Scheidel

Theses and Dissertations

Root hemiparasites are green plants that tap into a neighboring plant’s water-filled xylem to acquire inorganic nutrients, which can lead to an accumulation of nutrients in hemiparasite biomass. I performed an observational field study at Nachusa Grasslands and Franklin Creek State Natural Area (Lee County, IL) in 2019 to investigate how the presence of five root hemiparasites (Aureolaria grandiflora (Benth.) Pennell, Agalinis tenuifolia (Vahl) Raf., Castilleja sessiliflora (Pursh), Dasistoma macrophylla (Nutt.) Raf., Pedicularis canadensis L.) affects their communities through the (a)keystone species hypothesis, that hemiparasites will increase measures of diversity by altering competition among surrounding plant species, (b) ecological engineer …

Evidence Of Local Adaptation To Climate In An Invasive Ectotherm: A Study On The Eurasian Gypsy Moth (Lymantria Dispar) In North America, Phillip M. Gibbs

Theses and Dissertations

Invasive species exist in nearly every ecosystem both terrestrial and aquatic. Improving our understanding of the mechanisms that shape the ability of these organisms to physiologically cope with their surroundings will be crucial to preparing for future impacts of climate change. The Gypsy Moth (Lymantria dispar) has been expanding its range across North America over the last 100+ years since its arrival in Medford, Massachusetts. This study quantifies upper thermal limits (UTL) across 8 different populations of L. dispar in North America and seeks to determine if signals of local adaptation to climate across a latitudinal gradient may …

Enclosures And Dichotomies: Coexistence Vs. Distance In The Poems Of John Clare, Jordan P. Finn

Theses and Dissertations

John Clare’s poetry emphasizes an affinity with environment by suspending the distinction between the inside (subject) and the outside (object). Clare’s identification with objects and perception rather than subjects and aesthetics renders his work as a prescient and radical example of ecological poetry in the Romantic period. Raymond Williams’ “green language” and Timothy Morton’s ambient poetics both cite Clare as an ideal figure for their above theories and evoke Clare as a writer who positions the environment as governing thought rather than thought governing the environment. This thesis especially relates Clare to Morton’s Ecology without Nature, a study of …

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 …

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 …

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

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. …

Foraging Patterns And Population Density Of The Buff-Bellied Hummingbird (Amazilia Yucatanensis) In Hidalgo County, Tx, Megan I. Villarreal

Theses and Dissertations

The objective of this investigation was to examine the foraging patterns and population density of the Buff-bellied Hummingbird (Amazilia yucatanensis ) in Hidalgo County, TX. Previous studies showed that hummingbirds use flowers displaying traditional bird pollination (ornithophilous) characteristics: reddish coloration, tubular corolla, and extended anthers. Observation sessions noted type and frequency of flowering species utilized for nectar, characteristics, and number of individuals seen in each area. Amazilia yucatanensis showed higher use of ornithophilous flowers. Significant results found: f-ratio 5.45 > p-value (0.05) 3.24. Two highly utilized species showed the expected 20–40% sucrose content expected in ornithophilous flowers. Population density per …

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

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, anthropomorphism, …

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

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. With …

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

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. …

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 due …

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. …

Implications Of Introduced Mule Deer On Santa Catalina Island, California : Their Impacts, Population Ecology, And Management, Thad A. Manuwal

Theses and Dissertations

A small group of mule deer were introduced to Santa Catalina Island in the early
1930s. The mule deer population increased through the 1940s and 1950s and remains widespread and abundant today. Large browsing ungulates are not native to Santa Catalina Island and there is concern that nonnative mule deer are damaging endemic trees and shrubs on the island when foraging. This study was designed to develop quantitative information on diets, foraging behavior, movements, and population biology of mule deer on Catalina Island.

Diet analysis indicated mule deer are consuming a wide variety of native and
endemic plants found on …

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

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 increased daytime sea …

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 selection of Chukars. Chukars …

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

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 densities. To …

A Taxonomic And Ecologic Study Of The Riverbottom Forest On St. Mary River, Lee Creek And Belly River In Southwest Alberta, Canada, Robert Keith Shaw

Theses and Dissertations

The riverbottom forest community of St. Mary River, Lee Creek and Belly River in southwest Alberta, Canada is a unique ecological entity characterized by poplar species having their major Alberta distribution along these streams. Stands in the community are dominated by three tree species, six shrub species and nine herb species. Establishment of the community is dependent on climate and substrate; destruction is the result of progressive lateral stream-flow erosion. Soils are sandy loams above gravel, with pH values of 7.7 to 8.0 and soluble salt concentration of 176 to 458 parts per million. Trees in mature stands averaged 23.0 …