Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Theses/Dissertations

2016

Terrestrial and Aquatic Ecology

Institution
Keyword
Publication

Articles 1 - 30 of 99

Full-Text Articles in Life Sciences

Flight Of The Freshwater Fish, Michael H. Wilson Dec 2016

Flight Of The Freshwater Fish, Michael H. Wilson

Capstones

Michael H. Wilson

Capstone Abstract

December 27, 2016

Flight of the Freshwater Fish

The Hudson River provides for millions of people as a path for commercial and private transportation, a source of food and energy, and perhaps most importantly for many living in the tri-state area as a destination for recreation and relaxation. The most overlooked feature of the river is how the wildlife shows clear signs of a changing climate and rapid environmental response to the impacts of global warming on the river.

Entire populations of fish species in the lower Hudson have been forced to leave the river ...


Vertical Movement Of The Endangered James Spinymussel (Pleurobema Collina) And The Notched Rainbow Mussel (Villosa Constricta) In Response To Floods At Different Temperatures And Substrates: Implications For Conservation And Management, Dorottya Boisen Dec 2016

Vertical Movement Of The Endangered James Spinymussel (Pleurobema Collina) And The Notched Rainbow Mussel (Villosa Constricta) In Response To Floods At Different Temperatures And Substrates: Implications For Conservation And Management, Dorottya Boisen

Masters Theses, 2010-2019

Freshwater mussels are keystone species in their ecosystems, improving water and substrate quality for other organisms while they are alive, and buffering stream pH and providing shelter with their shells after they die. Approximately 70% of all freshwater mussel species are endangered globally. The James Spinymussel (Pleurobema collina) is a critically endangered species that lives in disparate tributaries of the James River of Virginia. Like other freshwater mussels, they have a cryptic appearance and behavior, making them difficult to find and therefore, to study and conserve. Previous studies indicate a higher percentage of mussels are surfaced during their breeding season ...


The Forgotten Cousin In Freshwater Community Ecology: Tidal Freshwater Wetlands, Jack R. Mclachlan Dec 2016

The Forgotten Cousin In Freshwater Community Ecology: Tidal Freshwater Wetlands, Jack R. Mclachlan

Electronic Theses and Dissertations

Tidal freshwaters are unique in their placement in the landscape, forming where freshwater riverine flows are sufficient to overwhelm the saline water of the incoming tide, but not strong enough to suppress tidal water-height fluctuations. Tidal freshwaters and their wetlands have been overlooked by freshwater and marine researchers alike; neither discipline considers tidal freshwaters to fall under their purview. Invertebrate communities in tidal freshwaters are thought to be species depauperate; the consensus is that they support fewer taxa than nearby non-tidal freshwaters, but little is known about how these communities are structured. This study investigated how tidal hydrology, an atypical ...


Integrating Habitat Suitability Modeling And Radio Telemetry To Describe Habitat Use Of The Western Massasaugas, Sistrurus T. Tergeminus, In Texas, Mitchell R. Barazowski Dec 2016

Integrating Habitat Suitability Modeling And Radio Telemetry To Describe Habitat Use Of The Western Massasaugas, Sistrurus T. Tergeminus, In Texas, Mitchell R. Barazowski

Biology Theses

Habitat suitability modeling using the software package MaxEnt (Phillips, Anderson, & Schapire, 2006) is a popular method for describing the habitat of rare species. MaxEnt uses “presence only” data to develop models; however presence data are highly skewed towards areas of high detection probability and these areas may not represent the full range of habitat use. Thusly, predictions from models developed using only data from areas with high detection probability may not represent all suitable habitat. This study tested the ability of MaxEnt models developed using three different data sets to accurately describe Western Massasauga (Sistrurus t. tergeminus) habitat at a local scale. Models were evaluated by their ability to predict high suitability values at locations of known snake occurrence. The first ...


The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez Dec 2016

The Influence Of The Invasive Chinese Tallow (Triadica Sebifera) Leaf Litter On Aquatic Chemistry And Microbial Community Composition, Raymond D. Montez

Electronic Theses and Dissertations

Global climate change and anthropogenic activity have facilitated the movement and invasive potential of nonnative plants in native environments. These invasions can have negative effects on ecosystem diversity and function. The nonnative and invasive plant, Chinese Tallow (Triadica sebifera), has already invaded much of the south eastern US where it is outcompeting native tree species and changing ecosystem diversity in a variety of habitats. Leaf litter from the Chinese tallow has been shown cause changes in dissolved oxygen and pH in the aquatic environment. Turbidity is also affected when Chinese tallow litter is present in water. A series of experiments ...


Assessing The Climate Change Vulnerability Of Ecosystem Types Of The Southwestern U.S., Francis J. Triepke, Esteban H. Muldavin, Maximillian M. Wahlberg, Timothy K. Lowrey, Donald A. Falk, Megan M. Friggens, Karen E. Bagne Dec 2016

Assessing The Climate Change Vulnerability Of Ecosystem Types Of The Southwestern U.S., Francis J. Triepke, Esteban H. Muldavin, Maximillian M. Wahlberg, Timothy K. Lowrey, Donald A. Falk, Megan M. Friggens, Karen E. Bagne

Biology ETDs

Climate change is challenging scientists and decision-makers to understand the complexities of climate change and to predict the related effects at scales relevant to environmental policy and the management of ecosystem services. Extraordinary change in climate, and the ensuing impacts to ecosystem services, are widely anticipated for the southwestern United States. Predicting the vulnerability of Southwest ecosystems and their components has been a priority of natural resource organizations over the past decade. Supplementing vulnerability assessments in the region with geospatial inputs of high thematic and spatial detail has become vital for supporting local analyses, planning, and decisions. In this context ...


Salvinia Molesta: An Assessment Of The Effects And Methods Of Eradication, Arti Lal Dec 2016

Salvinia Molesta: An Assessment Of The Effects And Methods Of Eradication, Arti Lal

Master's Projects and Capstones

Salvinia molesta is an invasive aquatic fern. It is now the second worse aquatic invader in the world. Since the 1930s, it has invaded most tropical and some temperate countries. S. molesta plants grow vegetatively and can increase in size rapidly. S. molesta can form thick mats of up to 1-meter-thick. There are a number of ways these thick mats negatively affect the environment: 1) reduce light to benthic organisms, 2) reduce oxygen in the water column for other organisms, 3) accumulate as organic matter at the bottom of the water column, 4) decrease nutrients for other organisms, and 5 ...


Trophic Ecology Of Green Turtles (Chelonia Mydas) From Dry Tortugas National Park, Florida, David C. Roche Dec 2016

Trophic Ecology Of Green Turtles (Chelonia Mydas) From Dry Tortugas National Park, Florida, David C. Roche

HCNSO Student Theses and Dissertations

Located 100 km west of Key West, Florida, Dry Tortugas National Park (DRTO) is a largely untouched subtropical marine ecosystem that serves as an important developmental habitat, nesting ground, and foraging area for several species of sea turtles, including green turtles. The Park supports a recovering population of green turtles comprised of resident juveniles, subadults, and adults of both sexes; nesting females include residents and migrating females that only return to nest. Stable isotope analysis has been applied widely to describe the trophic ecology of green turtles, from urbanized bays with significant anthropogenic input, to relatively pristine ecosystems with healthy ...


Assessing The Functional Similarity Of Native And Invasive Anolis Lizards In The Food Webs Of Structurally-Simple Habitats In Florida, Nathan W. Turnbough Dec 2016

Assessing The Functional Similarity Of Native And Invasive Anolis Lizards In The Food Webs Of Structurally-Simple Habitats In Florida, Nathan W. Turnbough

Doctoral Dissertations

Invasive species often displace ecologically-similar native species, but the extent to which invading and displaced species function similarly in the food web processes of invaded communities is largely unknown. I investigated whether populations and individuals of an invasive Anolis lizard (the brown anole, Anolis sagrei) and the native congener it displaces in Florida (the green anole, Anolis carolinensis) are functionally equivalent in the food webs of open and structurally-simple habitats. In a system of invaded and uninvaded dredge-spoils islands, I found that both arthropod communities and winter bird communities covaried with brown anole abundance (and therefore the identity of the ...


Migration Ecology Of American Woodcock (Scolopax Minor), Joseph Daniel Moore Dec 2016

Migration Ecology Of American Woodcock (Scolopax Minor), Joseph Daniel Moore

Theses and Dissertations

Improving the understanding of American woodcock (Scolopax minor) migration ecology has been identified as a priority information need for woodcock management. Developments in remote tracking technology and analytical techniques present an opportunity to gain insight into woodcock migratory connectivity and migration phenology and to evaluate the degree in which the current two-region (Eastern and Central) basis for woodcock management represents migratory movements. To analyze woodcock migration using band return records, I excluded observations that took place during the migratory period. Using this dataset, 17.9% of records showed crossover between management regions, higher than the < 5% crossover found in studies including non-migratory band returns. During autumn migration, woodcock from the Central Region largely migrated to destinations within the Central Region, whereas woodcock from the Eastern Region migrated to destinations across their wintering range, mixing with individuals from the Central Region. Between 2013 and 2016, I deployed 75 satellite transmitters on woodcock. I tracked the migration paths of 61 woodcock and documented 88 woodcock migrations. Average migration duration was longer during spring migration (53 days) than during autumn migration (31 days) because woodcock made a higher number of close-together migratory stopovers, not because woodcock stayed at individual stopovers longer during spring migration. Woodcock captured in the Central Management Region used 2 primary migrations routes: a Western Route and a Central Route. The Western Route ran north-south, connecting the breeding and wintering grounds of the Central Management Region. The hourglass-shaped Central Route connected an area on the wintering grounds reaching from Texas to Florida, to sites throughout northeastern North America. Woodcock following the Central Route funneled between the Appalachian Mountains and the Mississippi Alluvial Valley in western Tennessee during both autumn and spring migration. A higher than anticipated percentage (36%, n = 12) of marked woodcock captured in Texas and Louisiana and monitored during spring migration migrated to breeding-period sites in the Eastern Management Region, raising questions about the biological basis of managing woodcock as separate populations. The supplementary material includes woodcock capture information (Appendix I), information on individual stopovers (Appendix II), and migration maps for individual woodcock (Appendix III).


Fishes As A Template For Reticulate Evolution: A Case Study Involving Catostomus In The Colorado River Basin Of Western North America, Max Russell Bangs Dec 2016

Fishes As A Template For Reticulate Evolution: A Case Study Involving Catostomus In The Colorado River Basin Of Western North America, Max Russell Bangs

Theses and Dissertations

Hybridization is neither simplistic nor phylogenetically constrained, and post hoc introgression can have profound evolutionary effects. Most studies have focused on tractable model systems, rather than organisms with complicated phylogenetic histories. Finescale Sucker (genus Catostomus) in western North America is recognized as a paradigm of fish hybridization. Yet, its extent of historic and contemporary introgression is largely unstudied, an aspect that impedes the resolution of its phylogeny as a baseline for conservation. To explore reticulation in this group, I assayed variation of 20 Catostomus species across temporal and geographic scales by analyzing hundreds of samples and employing a combination of ...


Developing Best Management Practices For Interior Least Tern Habitat Restoration On The Mcclellan-Kerr Arkansas River Navigation System, John Gordon T. Ross Dec 2016

Developing Best Management Practices For Interior Least Tern Habitat Restoration On The Mcclellan-Kerr Arkansas River Navigation System, John Gordon T. Ross

Theses and Dissertations from 2016

The interior least tern (Sternula antillarum athalassos) is an endangered shorebird that nests on sandbars in river systems throughout the central United States, and which has lost habitat due to damming and channelization of these rivers. My study sought to quantify the status and trends of the population nesting in the McClellan-Kerr Arkansas River Navigation System (MKARNS) within Arkansas, and to establish best practices for nesting habitat management. The local population of terns remained steady between 2010 and 2014, with approximately 450 adults breeding in this section of MKARNS. Regression tree analysis and principal component analysis showed that colonies on ...


Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann Dec 2016

Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann

Master's Theses

The Mississippi – Alabama barrier island chain is experiencing accelerated sea level rise, decreased sediment supply, and frequent hurricane impacts. These three factors drive unprecedented rates of morphology change and ecosystem reduction. All islands in the chain have experienced land loss on the order of hectares per year since records began in the 1840s. In 1969, Hurricane Camille impacted as a Category 5, breaching Ship Island, and significantly reduced viable seagrass habitat. Hurricane Katrina impacted as a Category 3 in 2005, further widening Camille Cut. To better understand the sustainability of these important islands and the ecosystems they support, sediment transport ...


Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) Pre-Restoration Occupancy Patterns On Ship Island, Mississippi Sound With An Evaluation Of Designated Critical Habitat Use By Eastern And Western Population Segments, Page Elizabeth Vick Dec 2016

Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) Pre-Restoration Occupancy Patterns On Ship Island, Mississippi Sound With An Evaluation Of Designated Critical Habitat Use By Eastern And Western Population Segments, Page Elizabeth Vick

Master's Theses

Critical spawning and feeding habitat was designated for federally threatened, anadromous Gulf Sturgeon (GS) to aid in population recovery. This study examined GS occupancy, habitat use, and movement through critical habitat monitored by the Ship Island (SI) acoustic array during overwintering periods from 2011 to 2015 prior to MsCIP SI restoration. An occupancy index analyzed patterns of spatial and temporal habitat use of both western and eastern population segments (WPS and EPS, respectively) of GS on the SI array. The ends of SI along with the passes and cuts of the island, especially Dog Keys Pass (DKP), were occupied by ...


Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam Dec 2016

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C ...


It’S Complicated: Does Food Web Structure Affect Detrital Processing In Streams?, Stephen H. Tentinger Dec 2016

It’S Complicated: Does Food Web Structure Affect Detrital Processing In Streams?, Stephen H. Tentinger

Biology Theses

Trophic cascades involve powerful feeding interactions that can alter the flow of energy and the abundance of species in an ecosystem. In western NY streams, the negative impacts of a new benthic invertivore, the round goby (Neogobius melanostomus) is altering benthic community structure and leaf litter decomposition. Streams with round gobies have a reduced abundance of shredders and slower leaf decay than streams without gobies. However, crayfish, as shredders of leaf litter, may be large or aggressive enough to avoid predation by round gobies. I used a 30-day full factorial field experiment with blocks to determine if round gobies affected ...


An Analysis Of Morphometric Differentiation In Lake And River Populations Of The Emerald Shiner, Notropis Atherinoides, John J.V. Lang Dec 2016

An Analysis Of Morphometric Differentiation In Lake And River Populations Of The Emerald Shiner, Notropis Atherinoides, John J.V. Lang

Biology Theses

Understanding mechanisms that account for phenotypic variation has been of interest to biologists since the advent of Darwin’s theory of evolution by natural selection. It is now understood that adaptive divergence is a key driving force of intraspecific differentiation. Further, differences in habitat (e.g., flow regime, prey regime) have been shown to drive adaptive divergence in fish. For instance, fish inhabiting faster flowing water generally exhibit more fusiform bodies than their lake counterparts. Similarly, the partitioning of benthic and pelagic morphs generally results in smaller heads with the latter. This study used geometric shape analysis to assess morphological ...


Evaluating Resistance Surfaces For Modeling Wildlife Movement And Connectivity, Katherine Zeller Nov 2016

Evaluating Resistance Surfaces For Modeling Wildlife Movement And Connectivity, Katherine Zeller

Doctoral Dissertations

The continued growth of human populations and associated development in many areas of the world is causing persistent fragmentation of natural habitats. In response, wildlife corridors are often promoted as essential for the conservation of wildlife species. Wildlife corridors allow for the movement of individuals between habitat patches and confer many benefits including the maintenance of metapopulations and metapopulation dynamics, the maintenance of seasonal migratory routes, genetic exchange, and the potential for individuals and populations to shift their ranges in response to climate change.

Wildlife corridors are modeled across a resistance-to-movement surface where resistance represents the willingness of an organism ...


Ecological Consequences Of Lost Anadromous Forage Fish In Freshwater Ecosystems, Steven R. Mattocks Nov 2016

Ecological Consequences Of Lost Anadromous Forage Fish In Freshwater Ecosystems, Steven R. Mattocks

Masters Theses

Beginning in the early 1600s, dam construction in New England obstructed anadromous fish access to spawning grounds during migration. As a result, anadromous forage fish populations have declined, which has impacted freshwater, marine, and terrestrial ecosystems. To determine the impacts of dams on anadromous forage fish and freshwater ecosystems, I used historical and current data to estimate population changes in alewives (Alosa pseudoharengus) from 1600-1900. A significant reduction in spawning habitat occurred in New England as a result of 1,642 dams constructed between 1600 and 1900, resulting in 14.8% and 16.6% lake and stream habitat remaining by ...


Factors Affecting Habitat Quality For Wintering Wood Thrushes In A Coffee Growing Region In Honduras, Brett A. Bailey Nov 2016

Factors Affecting Habitat Quality For Wintering Wood Thrushes In A Coffee Growing Region In Honduras, Brett A. Bailey

Masters Theses

Amongst the diversity of taxa that occur in the Neotropics, 200 migratory bird species that breed in temperate North America can be found. Many of these populations have seen significant declines since the 1960s. The Wood Thrush, Hylocichla mustelina, is one such species. Shade coffee and other agroforestry practices show potential for benefiting migratory species, but the quality of coffee habitat and optimal habitat characteristics for Wood Thrushes remain unknown.

I surveyed a spatially complex, agricultural landscape in Honduras outside the recognized winter range of the Wood Thrush and radio-tagged 46 individuals within rustic coffee farms during the winters of ...


Understanding The Impact Of Commercial Harvest On White Suckers (Catostomus Commersonii) In Maine, Megan A. Begley Nov 2016

Understanding The Impact Of Commercial Harvest On White Suckers (Catostomus Commersonii) In Maine, Megan A. Begley

Electronic Theses and Dissertations

The State of Maine issues an unlimited number of commercial permits for the harvest of White Suckers Catostomus commersonii in Maine’s inland waters. The fishery provides a necessary source of fresh lobster Homarus americanus bait to coastal communities at a time when other bait sources are scarce. The impacts of the increasing number of permits and subsequent numbers of fishermen on the white sucker population is unknown. The Maine Department on Inland Fisheries and Wildlife (MDIFW) has closed a number of waters due to concerns that overfishing and incidental catch of other fish species may occur.

In Chapter 1 ...


Population Dynamics And Genetic Differentiation Of The Threatened Freshwater Mussel Species Fusconaia Askewi, Fusconaia Lananensis, And Pleurobema Riddellii, Edith D. Plants-Paris Aug 2016

Population Dynamics And Genetic Differentiation Of The Threatened Freshwater Mussel Species Fusconaia Askewi, Fusconaia Lananensis, And Pleurobema Riddellii, Edith D. Plants-Paris

Biology Theses

North America has the most diverse freshwater mussel fauna in the world with approximately 300 species; unfortunately, extinction rates for freshwater mussels rivals the rates of many other groups of organisms. Population-level natural life history data is essential in the management of species of conservation concern, yet basic information about freshwater mussel life-history and demographic traits are unknown for many species. To further complicate matters, taxonomic uncertainty exists among some members of the group. The work detailed herein had two goals: to gain further understanding of the taxonomic relationship between Fusconaia lananensis and F. askewi by sequencing genes that had ...


Decomposition Dynamics Under Climate Change Conditions In Boreal Peat, Rosa Del Giudice Aug 2016

Decomposition Dynamics Under Climate Change Conditions In Boreal Peat, Rosa Del Giudice

Electronic Thesis and Dissertation Repository

Boreal peatlands currently act as carbon sinks, but are projected to become carbon sources under climate change. Shifts in plant community composition alongside increased decomposition rates are potential mechanisms precipitating this change. My objective was to determine the decomposition potential of different peatland plant litters (Sphagnum magellanicum (peat moss), Carex magellanica (graminoid) and Chamaedaphne calyculata (woody shrub)) during short-term (48 hour) leaching and microbial decomposition (20 week) phases. The 48-hour leaching experiment measured mass loss and leachate chemistry of litters grown under ambient and elevated CO2, while the 20-week experiment measured heterotrophic respiration and mass loss of litters incubated ...


Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson Aug 2016

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment ...


Exploring The Threats Of Dams And Ocean Conditions: In-River Movements And Ocean Growth Of Atlantic Salmon (Salmo Salar) From Maine's Rivers, Lisa K. Izzo Aug 2016

Exploring The Threats Of Dams And Ocean Conditions: In-River Movements And Ocean Growth Of Atlantic Salmon (Salmo Salar) From Maine's Rivers, Lisa K. Izzo

Electronic Theses and Dissertations

Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout the range of the species, with many populations at the southern extent of the distribution being extirpated or endangered. While Maine is the last state in the country where adult Atlantic Salmon return to rivers each year to spawn, numbers have decreased dramatically in recent decades, with typically less than 2,000 spawners returning to all Maine's rivers combined. The complex life history of this species, which involves a juvenile freshwater phase followed by a marine phase that can last one to five years before returning to freshwater ...


Incomplete Denitrification In Thermus Species, Chrisabelle Mefferd Aug 2016

Incomplete Denitrification In Thermus Species, Chrisabelle Mefferd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Members the bacterial genus Thermus have been shown to be incomplete denitrifiers, terminating with nitrite or nitrous oxide (N2O). However, the ability to carry out denitrification and the evolution of nitrogen oxide reductase genes in Thermus remains poorly understood. This study tests the hypothesis that incomplete denitrification is common in Thermus and seeks to uncover patterns in the evolution of denitrification pathways in Thermus. Denitrification capacity was determined in a collection of 25 strains representing ten species of Thermus and phylogenetic analysis was performed to determine whether denitrification genes evolved horizontally in Thermus. No strains in this study reduced nitrate ...


Behavioral Differences Between Native And Exotic Invertebrate Prey Affect Susceptibility To Predation By A Native Amphibian Predator, Zachary Cava Aug 2016

Behavioral Differences Between Native And Exotic Invertebrate Prey Affect Susceptibility To Predation By A Native Amphibian Predator, Zachary Cava

Biology Theses

Invasive species threaten global biodiversity via mechanisms that include altering the dynamics and structure of native food webs. Whereas much research has focused on how exotic species respond to native predators, less is known about how native predators are affected by invasive prey. Here I investigate the response of a rare and threatened native predator—the Eastern Hellbender (Cryptobranchus alleganiensis) to a high-profile invasive crayfish species, Orconectes rusticus. Hellbenders have declined throughout much of their range, and although the potential for exotic predators (i.e. sport fish) to negatively impact C. alleganiensis has been addressed, effects of exotic prey on ...


Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe Aug 2016

Eucalyptus In Kenya; Impacts On Environment And Society, Brandy M. Garrett Kluthe

Theses and Dissertations

Eucalyptus trees were introduced to Kenya a little over a century ago. European colonization along with the development of a railway system increased the demand for a fast growing wood source. The expansion of the tree across the fertile lands in Kenya raises concerns about the environmental impact on ecosystems where it has been introduced. These concerns include degraded soils, loss of water resources, co-introduction of ectomycorrhizal species, and allelopathy. Economic benefits to local landowners were also explored as well as the potential for large Eucalyptus woodlots to maximize the sequestration of CO₂ from the atmosphere. This was examined through ...


The Interactive Effects Of Pesticide Exposure And Infectious Disease On Amphibian Hosts, Katherine M. Pochini Aug 2016

The Interactive Effects Of Pesticide Exposure And Infectious Disease On Amphibian Hosts, Katherine M. Pochini

Open Access Theses

Natural systems are home to a multitude of natural and anthropogenic stressors, which draw an array of effects on ecological communities. While these effects have been investigated individually, it is important, given the routine co-occurrence of these stressors, to understand their interactive effects. Pesticide exposure and infectious disease are two common, co-occurring stressors that each have documented detrimental effects on species and, as evidence suggests, may have interactive effects. Moreover, existing research suggests that these interactive effects are highly context dependent, eliciting different results based on species, disease agent, toxin, and environment. Given the variability with which species may experience ...


Ecosystem Level Effects Of Climate Change On Northern Peatlands, Catherine M. Dieleman Jul 2016

Ecosystem Level Effects Of Climate Change On Northern Peatlands, Catherine M. Dieleman

Electronic Thesis and Dissertation Repository

Northern peatlands are the world’s most efficient terrestrial ecosystems at storing carbon. The effects of global climate change are expected to be intensified in high latitude regions of the northern hemisphere, where peatlands are a dominant landscape feature. Accordingly, there is concern that climate change will change peatlands from carbon sinks into carbon sources. In order to better understand the impacts of climate change on peatland ecosystems, the research presented in this dissertation focuses on several mesocosm experiments conducted to develop a better understanding of the interactive effects of three key climate change stressors (increased atmospheric CO2, increased ...