Life Sciences Commons^™

Riparian Ecosystem Response To Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality In The Great Smoky Mountains National Park, Usa, Misty Dawn Huddleston

Doctoral Dissertations

An invasive insect, hemlock woolly adelgid (HWA), has initiated widespread hemlock decline and mortality in the Great Smoky Mountains National Park (GSMNP). Riparian hemlock mortality impacts on vegetative and aquatic systems of first-order, headwater streams were evaluated. Reference sites for this study were representative of the best available conditions within the GSMNP, with initial stages of HWA presence. Impacted sites were defined as areas with over 90 percent hemlock mortality. Impacted streams had decreased canopy coverage and increased light availability. Residual red maple, yellow birch, and sweet birch capitalized on the loss of hemlock, with increases in relative basal area …

Multiple Responses By Cerulean Warblers To Experimental Forest Disturbance In The Appalachian Mountains, Than James Boves

Doctoral Dissertations

The Cerulean Warbler (Setophaga cerulea) is a mature forest obligate and one of the fastest declining songbird species in the United States. This decline may be related to a lack of disturbance within contemporary forests; however, the consequences of disturbance on the species have not been rigorously evaluated. Thus, we assessed multiple responses by Cerulean Warblers to a range of experimental forest disturbances across the core of their breeding range in the Appalachian Mountains. We quantified individual and population responses to these manipulations, and assessed the potential consequences of disturbance on the sexual signaling system. Male ceruleans were …

Bycatch Of The Lake Pontchartrain Basin Inshore Shrimp Fishery And Its Effect On Two Sea Catfish Species: The Gafftopsail Catfish (Bagre Marinus) And The Hardhead Catfish (Ariopsis Felis), Scott P. Eustis

University of New Orleans Theses and Dissertations

In Lake Pontchartrain Basin, commercial fishing in estuarine habitats impacts many non-target species collected as bycatch. I investigated the bycatch assemblages collected by commercial vessels and compared these to assemblages collected by typical fishery-independent methods. I compared assemblages using analysis of similarity (ANOSIM) and determined important species by weight and abundance using similarity percentages analyses (SIMPER). I also examined differences in size-class distributions by gear type using density kernel plots and Mann-Whitney U tests. The two gear types collected significantly different assemblages (ANOSIM R = 0.522, p = 0.001) and gear type explained more composition differences than other factors such …

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation combines investigation of the large-scale responses of bryophyte species diversity and distribution with small-scale physiological adaptations to global change. These two areas of inquiry are linked because one way to predict plant species responses to global change is to examine their distribution across current ecological gradients produced by factors such as latitude and elevation. By examining these biogeographic patterns one can identify those species that have a narrow tolerance and therefore are most sensitive to change. Selected bryophytes might then be used as indicator species in long-term monitoring programs. Where historical data exist, these can be used to …

Microbial Impacts On Endocrine Disrupting Contaminants: Las Vegas Wash And Lake Mead, Nevada, Susanna May Blunt

UNLV Theses, Dissertations, Professional Papers, and Capstones

International concern over endocrine disrupting chemicals (EDCs) has become heightened in recent years as more studies reveal their persistence in the environment and their detrimental effects on wildlife. However, little is known about the role of microorganisms in the fate and transport of these compounds in surface waters. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater effluent, provided a unique experimental system in which to study the role microorganisms play in the dispersal of these compounds in aquatic systems. Samples were collected from the Las Vegas Wash downstream of the Las Vegas Valley's …

The Ecology Of The Timber Rattlesnake (Crotalus Horridus) In Southeastern Virginia, Scott M. Goetz

Biological Sciences Theses & Dissertations

Few studies have examined the relationship between forest canopy structure and the ecology of the timber rattlesnake (Crotalus horridus). I used radiotelemetry to compare the movements, activity range sizes and behaviors of timber rattlesnakes before and after a large-scale natural disturbance that opened a previously closed canopy. The disturbance was Hurricane Isabel which made landfall in northeast North Carolina and southeastern Virginia in 2003. Isabel created gaps in the canopy through tree blowdown, resulting in a 16.6% opening in the forest canopy at my study site, in southeastern Virginia. I compared six years of female tracking data from …

Trace Metal Limitation And Its Role In Oxidative Stress Of Coral Algal Symbionts; Implications For Thermally Induced Coral Bleaching Events., Katrina Lynn Iglic

Electronic Thesis and Dissertation Repository

Coral bleaching, the process in which corals expel their photosynthetic symbionts (Genus Symbiodinium), is caused by high temperature and irradiance stress. The synergistic effect of each stressor is the generation of damaging reactive oxygen and nitrogen species (ROS and RNS), which are normally mitigated physiologically by antioxidant enzyme activity. Antioxidant enzymes require iron, copper, manganese and zinc in their structure and the limited nature of these trace metals in reef environments may enhance ROS production under elevated temperature and irradiance. The hypothesis tested within this thesis was that a limited availability of the trace metals Fe, Mn, Cu and …

Classifying And Mapping Diversity In A Species-Poor System: The Mangrove Meta-Community Of Laguna Chacahua National Park, Oaxaca, Mexico, Elizabeth Kay Weisgerber

Master's Theses

ABSTRACT

Classifying and Mapping Diversity in a Species-Poor System: the mangrove meta-community of Laguna Chacahua National Park, Oaxaca, Mexico

by

Elizabeth Kay Weisgerber

Both field transects and imagery grid plots were analyzed with the goal of creating a community classification map for the mangrove forest of Parque Nacional Lagunas de Chacahua. In total, data was collected in 49 sites throughout the park, recording measures such as DBH, basal area, estimated dominance, frequency, cover and relative dominance. Field locations were marked and georeferenced with a GPS and grid plots overlaid on satellite imagery of the park were generated via a random …

Dissolved And Colloidal Element Transport Through The Coastal Transition Zone, Moo Joon Shim

Dissertations

There are several factors (e.g., hurricanes, floodplain, and anthropogenic sources) that could modify trace element behavior through the coastal transition zone (CTZ). However, there is still a lack of information about these variables in affecting trace elements in the CTZ. For this study, water samples were collected in the Pearl River (PR), Bay of St. Louis (BSL), and the Mississippi River plume to study the effects of these factors on trace element.

A possible effect of Hurricane Katrina on water quality was examined in the East Pearl River (EPR). Hurricane Katrina could have resulted in increased inputs of organic matter …

Rats As Forest Pests In Southeastern Virginia: Girdling By The Hispid Cotton Rat Sigmodon Hispidus As A Significant Source Of Mortality Of Loblolly Pines (Pinus Taeda) In A Successional Pine Forest, Robyn M. Nadolny

Biological Sciences Theses & Dissertations

The hispid cotton rat (Sigmodon hispidus) is a common field rodent throughout the southeastern US, where volunteer loblolly pine trees (Pinus taeda) invade open space and begin the process of ecological succession from field to pine forest. Recent analysis of the diet of S. hispidus indicates that loblolly pine bark is stripped and eaten during the winter months. In this study, we explored the extent of rodent girdling on a 1.23 ha grid in a successional pine forest in southeastern Virginia. During the winter of 2005 we observed damage to 65% of trees in our study area, with 98% …

Extent, Characteristics And Downstream Effects Of Stream Enclosure In Southwestern Ontario, Katie L. Stammler

Electronic Thesis and Dissertation Repository

In a 16000 km² area of southwestern Ontario, almost 15% of all streams have been enclosed (buried) largely for agricultural purposes. ArcGIS was used to characterize the natural features of catchments and to calculate enclosedness (proportion of stream network enclosed; x̅ = 16.5%, n = 10106). Catchments with the highest enclosedness received >990 mm of precipitation annually and had high drainage density (>1.9 km/km²), while catchments with the lowest enclosedness receivedannually, were characterized by clay and undrumlinized till plains and had relatively shallow water tables (m). These natural features influence where enclosure is likely to occur, …

Hydrologic Alteration And Sedimentation In The Upper Henry's Fork Watershed, Amelie Jeanne Charnaux

Master's Theses

Abstract

Hydrologic Alteration and Sedimentation in the Upper Henry’s Fork Watershed

Amelie Jeanne Charnaux

The Henry’s Fork of the Snake River is venerated by the global recreational community as one of the finest trout fishing streams on the planet. Furthermore, this remarkable waterway flows within the bounds of one of the most important ecological corridors in the equally world-renowned Greater Yellowstone Ecosystem. While the recreational and biological features of this corner of Idaho may capture the interest of the broader public, the waterway is equally significant to the livelihoods of local interests, such as the ranching and farming communities. With …

Harmful Algal Bloom (Hab) Communities And Co-Occurring Species In Relation To Near Shore Ocean Dynamics In San Luis Bay, California, Samuel Christopher Rankin

Master's Theses

The occurrence of phytoplankton taxa, with special focus on harmful algal bloom (HAB) taxa, was monitored for one year off the central coast of California to examine both their co-occurrence and physical and chemical variables influencing their temporal patterns. Bi-weekly samples were taken from October 6, 2008 to October 5, 2009 in San Luis Obispo Bay, CA. Canonical correspondence analysis (CCA) of weekly samples indicated that 46.1% of the variability in species abundance was explained by the variables in the model, higher than previous reports. Cluster analysis divided phytoplankton communities into HAB and non-HAB groups of species, while shared distribution …

Trophic Ecology Of Burrowing Owls In Natural And Agricultural Habitats And An Analysis Of Predator Communities Using Stable Isotopes Of Carbon And Nitrogen, Kathlyn Jean Mcvey

Boise State University Theses and Dissertations

Stable isotopes of carbon and nitrogen can provide powerful tools for estimating the trophic positions of animals and determining the source or the primary producer of a food web. I used stable isotopes analysis of carbon (δ¹³C) and nitrogen (δ¹⁵N) to investigate the trophic position of burrowing owls (Athene cunicularia) in agricultural and natural habitats and trophic relationships of a community of vertebrate predators in the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA), located in southern Idaho.

Burrowing owl populations have declined across much of North America owing to loss …

Co-Development Of Biological Soil Crusts, Soil-Geomorphology, And Landscape Biogeochemistry In The Mojave Desert, Nevada, U.S.A. – Implications For Ecological Management, Amanda Jean Williams

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are complex matrices of soil particles, mosses, lichens, and cyanobacteria that prevent erosion and influence water and energy balances, soil fertility, and vascular plant germination. The processes that form BSCs, the factors that control their distribution, and the ecosystem feedbacks that they sustain are poorly understood. This dissertation employed a novel interdisciplinary approach to address those research unknowns through investigations of the micromorphological structure, soil-geomorphic relationships, and biogeochemical feedbacks of BSCs in the Mojave Desert.

A micromorphological study of BSCs resulted in a succession model that illustrates how crust formative processes and structures change through time. …

Interannual Variability In American Lobster Settlement: Correlations With Sea Surface Temperature, Wind Stress And River Discharge, Mahima Jaini

Electronic Theses and Dissertations

Recruitment to benthic marine populations is fundamentally a biophysical problem. The American Lobster Settlement Index is an annual diver-based survey of the young-of-year American lobsters (Homarus americanus) found in inshore nurseries in New England, USA and Atlantic Canada at the end of the postlarval settlement season. The considerable interannual variability in the settlement index suggests that environmental factors play an important role in regulating planktonic larval supply and transport. In this study, I focused on the longest settlement time series from three oceanographically contrasting regions: Midcoast Maine, coastal Rhode Island and the lower Bay of Fundy. Sampling in these regions …

A Study Of Habitat Selection And Fluctuating Asymmetry Of Amybstoma Tigrinum At Henderson Island Wildlife Management Area In Jefferson County Tn., Christopher Scott Ogle

Electronic Theses and Dissertations

Studies were conducted on a population of tiger salamanders, Ambystoma tigrinum, at Henderson Island Wildlife Management Area in Jefferson County, TN. Tests were conducted to locate the nonbreeding habitat of the salamanders and to detect any difference in fluctuating asymmetry (FA) between larval populations in a large, permanent pond and an ephemeral wetland. Drift fences were installed with pitfall traps at selected locations around each pond to determine nonbreeding habitat use by adults. Most adult salamanders were found using a blackberry (Rubus sp.) dominated old-field, a grassy field, and a shrub-grass mix field, which were all adjacent …

Spatial Ecology Of The Spotted Salamander Ambystoma Maculatum During The Nonbreeding Season., Dale Patrick Ledford

Electronic Theses and Dissertations

Spotted Salamanders, Ambystoma maculatum, are a widely distributed pond-breeding amphibian that spends an estimated 95% of its life in woodlands surrounding breeding ponds. Their terrestrial ecology remains poorly understood. Few studies have tracked the movement patterns of Spotted Salamanders, and they have given limited information on fine scale patterns. Studies of distribution around vernal pool environments have brought increased attention to their terrestrial ecology. To this end I tracked a sample of Passive Integrated Transponder (PIT) tagged animals with a Radio Frequency Identification Device (RFID). Quadrat-variance methods and a Poisson distribution were used to analyze spatial distribution patterns over …

Activation Of Amp-Activated Protein Kinase As An Early Indicator For Stress In The Lobster, Homarus Americanus, Stephanie Podolski

All Theses And Dissertations

Variations in water temperature, salinity, pH, and oxygen concentration are stressors that marine invertebrates face on a daily basis. Each of these physiological stressors creates a large cellular demand for energy. In mammals, energy metabolism is regulated by the enzyme AMP-activated protein kinase (AMPK), which is highly conserved during evolution. This project was designed to test the hypothesis that AMPK is present and activated by temperature, hypoxia, and anoxia stress in the lobster, Homarus americanus.

Animals were exposed to a rapid and progressive increase in temperature (6ºC per hour) beginning at 14 ºC. We measured lactate concentrations and AMPK …

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997). As far as we know, no previous data have been compiled regarding hormones and condition index of guppies. In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River. Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator. The condition …

The River Continuum Redux: Aquatic Insect Diets Reveal The Importance Of Autochthonous Resources In The Salmon River, Idaho, Kathryn Vallis

Master's Theses

Along a river network, changes in the physical characteristics of a stream - changes articulated by the River Continuum Concept (RCC) - have been predicted to influence stream food webs, particularly the resources supporting aquatic macroinvertebrates. Although diets of macroinvertebrates can track resource availability along the longitudinal gradient of streams, insect diets were not assessed in the original RCC study; rather, insects were grouped into functional feeding groups (FFGs). In addition, global climate change is increasing the frequency and spatial extent of wildfire and beetle outbreaks throughout the western United States and could affect riparian vegetation and the amount of …

Community Structure And Secondary Production Of Aquatic Macroinvertebrates In Coastal Wetland Ponds Of The West Copper River Delta, Alaska, Following Tectonic Uplift, Ryan Glen Van Duzor

Master's Theses

The Great Alaska Earthquake of 1964 (magnitude 9.2) greatly altered the coastal landscape in southcentral Alaska and had particularly dramatic effects on the Copper River Delta (CRD), an ecologically and economically important area within the Chugach National Forest. The earthquake caused tectonic uplift (up to 3.5m) of the CRD coastal tidal marsh and transformed it into a perched freshwater marsh. Copper River Delta ponds, which are crucial habitat to a myriad of migrating songbirds, shorebirds, and waterfowl, are of particular interest to wildlife managers in the CRD and along the Pacific coasts of North, Central and South America. This study …

A Virtual Phytosaur Endocast And Its Implications For Sensory System Evolution In Archosaurs, Waymon Holloway

Theses, Dissertations and Capstones

Due to the overall morphological similarities between the Triassic archosaurs of the order Phytosauria and extant crocodilians, most studies have assumed that the two shared similar lifestyles. Many studies involving phytosaurs have focused on the external cranial morphology of various taxa. Internal cranial anatomy has received relatively little attention. As a result, comparative morphology studies of the braincases interior, or endocast, of phytosaurs are an area of potential exploration. Just as modern medical Xray computed tomography (CT) can be used to create three-dimensional images of internal structures of living subjects, such technology offers a non-invasive means of studying the internal …

Plesiosaur Body Shape And Its Impact On Hydrodynamic Properties, Courtney D. Richards

Theses, Dissertations and Capstones

Despite the variability of cross-sectional body shape within Plesiosauria, its impact on plesiosaur buoyancy and stability has never been investigated. This study focused on Tatenectes, Cryptoclidus, and Muraenosaurus due to their variable body morphologies. Reconstructions were created based on measurements and photographs from fossil remains. The ability of computer models, based upon the reconstructions, to reach equilibrium after submersion, sink via lung deflation, and recover from a lateral roll was tested. For the computer models, Muraenosaurus was replaced with Thalassomedon, which had a similar morphology. Cryptoclidus and Thalassomedon recovered from submersion faster than Tatenectes. All models achieved negative buoyancy with …

The Little Coal River Improvement Project, West Virginia: An Initial Study Of Sediment, Bacteria And Benthic Macroinvertebrates, Emily Vargo

Theses, Dissertations and Capstones

The Little Coal River, located in southern West Virginia, has undergone many changes over the last few years in an effort to reverse the negative effects of various point source and non-point source pollutions. Marshall University, in cooperation with the West Virginia Department of Environmental Protection, Army Corp of Engineers, and the Coal River Group, has designed and implemented a plan for rehabilitation known as the Little Coal Improvement Project. Several improvement structures were strategically installed within the Little Coal River during the summer of 2007. The functions of these structures include sediment flushing and overall habitat improvement. Monitoring these …

Phylogenetic Analysis Of Blacknose Dace (Rhinichthys) In West Virginia Streams, Samantha Taylor

Theses, Dissertations and Capstones

Blacknose dace (Rhinichthys) are one of the most common cyprinid fishes in eastern North America. They also have been a topic of debate for over 30 years because morphology-based systematics has failed to clearly define their taxa. Taxonomists classify the complex into two species and one subspecies: the eastern form, R. atratulus atratulus; and the western form R. obtusus obtusus, and southern form R. obtusus meleagris. This research uses the mitochondrial cytochrome b gene and genomic RAG 2 gene in a phylogenetic analysis to help clarify species relations according to differences between each current species. Maps have been created to …

Forest Succession And Amphibian Migrations: Implications For Landscape Connectivity, Viorel Dan Popescu

Electronic Theses and Dissertations

Conservation of forest-dependent amphibians is dependent on finding a balance between timber management and species’ habitat requirements. Accurate predictions of the response of amphibian communities to disturbance rely on a good understanding of the scales at which ecological processes affect distribution and abundance through space and time. I investigated the response of 14 species to four different forestry treatments (partial harvest, clearcut with coarse woody debris [CWD] removed, clearcut with CWD retained, and uncut control) over a six-year period, using 2.1-ha experimental treatments. Forest amphibians showed a strong negative response to complete canopy removal at a broad spatial scale, but …

Floristic And Environmental Characteristics Of Sub-Boreal Peatlands Of Minnesota And Western Wisconsin, Kevin Douglas Clement

All Graduate Theses, Dissertations, and Other Capstone Projects

Peatland communities in the sub-boreal region of Minnesota and western Wisconsin were characterized by floristic composition, structure and environmental characteristics to determine the natural variation among peatland communities in the region and their shared associations with the boreal and temperate peatlands of North America. Floristic classification revealed five, distinct peatland community types, identified as Sphagnum Bogs, Herbaceous Fens, Forested Fens, Rich/Calcareous Fens and Phalaris anrundinacea dominated peatlands. Differences among sub-boreal peatlands largely reflected changes in the significant indicator and dominant plant species identified, which were found to exhibit high fidelities to a particular peatland community type. Floristic variations among sub-boreal …

Buffernomics: Assessing Willingness To Pay For Lake Conservation On North Pond And East Pond, Sophie D. Sarkar

Honors Theses

Hedonic property valuations in Maine have estimated that a one-meter decrease in water clarity can reduce shoreline property values by 4 to 16%. To avoid a loss on their lakefront investment, shoreline property owners have a particularly large incentive to conserve lake water quality. Nevertheless, while some shoreline residents voluntarily install vegetated buffers and actively participate in lake stewardship, others continue to ignore shoreline zoning laws at the expense of lake health. In this thesis, I examine the dichotomy of active and indifferent shoreline residents by analyzing the motivations that distinguish residents who are willing to pay (WTP) for and …

Zooplankton Of The Belgrade Lakes: The Influence Of Top-Down And Bottom-Up Forces In Family Abundance, Kimberly M. Bittler

Honors Theses

The purpose of this study was to assess the abundance and family diversity of zooplankton communities in the Belgrade Lakes, and to identify the broad scale and local variables that structure zooplankton communities in this region. The local effects of shoreline development and the presence of macrophyte patches were compared to larger scale variables, such as watershed wide residential development. Zooplankton are an intermediate link in the freshwater food web, and communities respond both to predation pressures as well as nutrient inputs. Shoreline development was expected to influence zooplankton densities by the increased nutrient inputs via erosion off developed sites …