Ecology and Evolutionary Biology Commons^™

Prymnesium Parvum And Fish Kills In A Southern Nevada Man-~Made Reservoir, Tara Gregg

UNLV Theses, Dissertations, Professional Papers, and Capstones

The water chemistry of Lake Las Vegas (LLV), a Southern Nevada man-made reservoir, is influenced by both anthropogenic and natural sources. These sources affect the reservoir's water chemistry, which may promote harmful algal blooms (HABs) leading to massive fish kill events. Fish kills, caused by the golden algaePrymnesium parvum (P. parvum), continue to pose a threat in the reservoir. However, no effective treatments to controlP. parvumin large reservoirs such as LLV have been determined. This cross-sectional study evaluated important variables that may affectP. parvumHABs in LLV, including non-P. parvumbiomass (mg/m3), total zooplankton abundance (#/m3), temperature, TDS (salinity), mineral concentration (Ca, …

Pronghorn (Antilocapra Americana) Offspring Recruitment On The Carrizo Plain National Monument: Evaluating The Effects Of Low Population Density And Marginal Habitat Quality., Diego Ramirez Johnson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Demographic fluctuation among ungulate populations is strongly linked to variability in recruitment. Rates of recruitment are subject to various forms of density-dependent and density-independent regulation. For species which benefit from the presence of conspecifics, reduced population density can decrease rates of recruitment and trigger a decline in per capita growth. Termed the Allee effect, this scenario can cause demographic collapse and population extinction. For many ungulate species, predation on juveniles is reduced when the timing and distribution of births is synchronized within a local population. Because birth synchrony is density-dependent, it may act as a mechanism for the Allee effect …

Religion, Partisanship, And Attitudes Toward Science Policy, Ted G. Jelen, Linda A. Lockett

Political Science Faculty Research

We examine issues involving science which have been contested in recent public debate. These “contested science” issues include human evolution, stem-cell research, and climate change. We find that few respondents evince consistently skeptical attitudes toward science issues, and that religious variables are generally strong predictors of attitudes toward individual issues. Furthermore, and contrary to analyses of elite discourse, partisan identification is not generally predictive of attitudes toward contested scientific issues.

Impacts And Management Of Hemlock Woolly Adelgid In National Parks Of The Eastern United States, Scott R. Abella

Life Sciences Faculty Research

No abstract provided.

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

Time-Dependent Random Effect Poisson Random Field Model For Polymorphism Within And Between Two Related Species, Shilei Zhou

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molecular evolution is partially driven by mutation, selection, random genetic drift, or combination of the three factors. To quantify the magnitude of these genetic forces, a previously developed time-dependent fixed effect Poisson random field model provides powerful likelihood and Bayesian estimates of mutation rate, selection coefficient, and species divergence time. The assumption of the fixed effect model that selection intensity is constant within a genetic locus but varies across genes is obviously biologically unrealistic, but it serves the original purpose of making statistical inference about selection and divergence between two related species they are individually at mutation-selection-drift inequilibrium. By relaxing …

Ichnology And Paleoecology Of The Jurassic Aztec Sandstone, Heather Marie Stoller

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study I describe and interpret tracks and trackways of the Jurassic Aztec Sandstone of southern Nevada and southern California. This study involved mapping of all known tracks and trackways, including foot length, stride length, and trackway width. Photogrammetric data, collected by Bureau of Land Management scientists, were utilized for several trackways in Red Rock Canyon National Conservation Area.

More than three hundred tracks belonging to five ichnotaxa were documented within the Aztec Sandstone, including about 165 tridactylGrallator, 250 tetradactyl (four-toed)Brasilichniumtracks, and 7 arthropod trackways ofOctopodichnusandPaleohelcura. Four of the five ichnotaxa were not previously reported from the Aztec Sandstone. …

Custodianship Of The Walking Box Ranch Property: Project Compendium, Margaret N. Rees

Walking Box Ranch

This Project Compendium contains information and products resulting from a multi-year cooperative effort between the Bureau of Land Management (BLM) Las Vegas Field Office and University of Nevada, Las Vegas (UNLV) to care for and make available a BLM-owned Southern Nevada historic property: Walking Box Ranch. This project was focused, primarily, on the custodianship of the site through UNLV’s design, management, and coordination of a resident caretaker program, which was carried out by a series of excellent volunteers. University experts contributed to the decision-making process for necessary repairs and site security was enhanced through an innovative volunteer project open to …

Paleoecology Of Late Pleistocene Megaherbivores: Stable Isotope Reconstruction Of Environment, Climate, And Response, Aubrey Mae Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Late Pleistocene megaherbivore communities of the Pacific and Mountain West states of California and Nevada are under-analyzed in regard to ecological function (diet, mobility, niche partitioning, and range of ecological tolerance). Stable isotope analysis is a powerful tool that is known to recover primary paleodiet and paleoenvironmental information from biogenic materials, such as enamel and dentin. This dissertation explores the use of carbon and oxygen stable isotopes in Late Pleistocene (40-10 Ka) megaherbivore teeth to gain a better understanding of inter- and intra-specific behavior and reconstruct Late Pleistocene ecosystems of California and Nevada. Radiocarbon dates exist for most of the …

Understanding Basin Specific Life History Characteristics Of Lake Mead Quagga Mussels (Dreissena Bugensis) And A Potential Treatment Using Uv Radiation In Laboratory Studies, Melissa Thaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

The quagga mussel (Dreissena bugensis) is an aquatic invasive species that is spreading throughout Lake Mead and other western waterways. Unlike their native waters in Eurasia, Lake Mead exhibits year round warm temperatures, high calcium levels and a lack of natural predators, all of which are very favorable conditions for their growth and spread. Dreissena bugensis reproduce and colonize hard surfaces rapidly, where they filter large amounts of water. They disrupt the aquatic food chain and interfere with infrastructure that is exposed to lake water. There is an urgent need to understand Dreissena bugensis life history characteristics within this new …

Integrating, Developing, And Testing Methods To Generate More Cohesive Approaches To Biogeographic Inference, Mallory Elizabeth Eckstut

UNLV Theses, Dissertations, Professional Papers, and Capstones

As a fundamental component of the developing discipline of conservation biogeography, broadscale analyses of biotic assembly and disassembly across multiple temporal and spatial scales provide an enhanced understanding of how geologic transformations and climate oscillations have shaped extant patterns of biodiversity. As with any scientific field, there are limitations in the case of biogeographic historical reconstructions. Historical reconstructions are only as robust as the theoretical underpinnings of the methods of reconstruction (including data collection, quality, analysis, and interpretation). Nevertheless, historical reconstructions of species distributions can help inform our understanding of how species respond to environmental change.

My dissertation takes a …

Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the variation in plant communities can be explained by the dispersal of individuals across landscapes, an ecological process that contributes to clinal variation, post-disturbance recovery and habitat occupancy. The role of dispersal is of particular concern for Mojave Desert plant communities that may not be able to tolerate recent departures from historical fire regimes. The aim of this thesis was to infer how dispersal is reflected by patterns of diversity in disturbed and undisturbed bryophyte communities in the Spring Mountains of southern Nevada. Chapter 2 presents an examination of sub-surface bryophyte communities (propagule "soil-banks") along a 1400 m …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …

Understanding Effects Of Changes In Land Use, Environmental Parameters, Habitat Characteristics On The Great Basin Aquatic Invertebrates Using Ecological Stoichiometric Theory, Knut Mehler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many freshwater ecosystems in the Great Basin have undergone dramatic alteration over the past decades due to groundwater withdrawal, water diversion and changes in land use. These changes have affected benthic food web dynamics by altering the availability of chemical key elements for primary and secondary producers, by loss of biodiversity and extinction of endemic species. However, only few studies are available that addresses the link between changes in land use, habitat characteristics and its effects on benthic macroinvertebrates (BMI) communities comprehensively and little attention has been given to integrating physiochemical aspects to link ecosystem functions.

This dissertation analyzes the …

The Effects Of Starvation Selection On Drosophila Melanogaster Life History And Development, Lauren A. Reynolds

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, animals may endure periods of famine to complete their life cycles. Starvation stress will increase in populations as climates around the world change. To predict how populations may respond to such a stress, laboratory experimentation becomes essential. The evolutionary process of adaptation, its innovations and their trade-offs, can be studied in populations experiencing starvation stress. For this purpose outbred populations ofDrosophila melanogasterwere selected for starvation resistance in the laboratory.

After 60+ generations of starvation selection the starvation-selected flies have gone from surviving 2-3 days without food to 12-14 days without food. How this amazing feat of resistance is …

Soil Moisture Recognition And The Spatial Distribution Of Storm Activity In The Mojave Desert Using High-Resolution Aster And Modis Imagery For Thermophysical Mapping, Russell J. Skuse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate models suggest that the Mojave Desert ecoregion is vulnerable to becoming drier in the future, and as the human population grows and development increases, environmental stresses will likely increase. Determining the spatial distribution and variation of soil moisture on a regional scale is an essential component to climate change, hydrologic, and habitat analyses. Soil permeability and sediment stability are characteristics that have been shown to be measurable from remote sensing observations. The primary objective of this project is to map the mechanical composition of the surface materials in the Mojave Desert ecoregion with implications for soil permeability, sediment stability, …

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending January 10, 2013, Margaret N. Rees

Walking Box Ranch

• BLM notified UNLV on Nov 7, 2012 that they had cancelled the WBR solicitation for a general contractor and that they were reconsidering the scope of the project. BLM and UNLV met on Nov. 22, 2012 and BLM updated UNLV on their decision to terminate the task agreement for the field and research station, and to modify plans for interpretation at the future WBR Visitor Center. BLM and UNLV will meet Feb. 7, 2013 to discuss the path forward regarding interpretation and the Visitor’s Center.
• UNLV is continuing to work with direction from Carolyn Shelton, BLM interpreter, to collect interpretive …

Evolution Of The Human Diet: What We Can Learn From Hunters And Gatherers, Kara Osborne, Alyssa Crittenden

McNair Poster Presentations

The study of hunter-gatherer populations around the world can greatly inform our understanding of the evolution of the human diet. Ethnographic research of modern hunter-gatherers has been used to infer the possible food consump­tion and acquisition patterns of our ancestors. Hunter-gatherers provide the in­formation necessary for the understanding of the past human diet, due to these populations living similar lifestyles in similar environments, therefore procuring similar foods.

The Hadza, a group of nomadic hunters and gatherers living in Tanzania, East Africa, are one of the primary populations that nutritional anthropologists study to infer what possible foods our ancestors acquired and …

Moving Forward: Preventing Water Shortage For Nevada, Sandra Blandon, Brianna Lyon

Anthropology 100: Feast and Famine In a Global World Poster Assignment

Southern Nevada is located in the arid Mojave Desert, which averages about 4 inches of rain each year. Southern Nevada gets about 90% of its water supply from the Colorado River. Seven western states and Mexico share the river. This means that The Colorado River provides water to 25 million people.

Restoration Of Biological Soil Crust On Disturbed Gypsiferous Soils In Lake Mead National Recreation Area, Eastern Mojave Desert, Lindsay P. Chiquoine

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are sensitive to anthropogenic disturbances. Natural recovery takes many years. Active restoration decreases recovery time. Native BSC inocula, which included lichens and mosses, salvaged from gypsiferous soil habitats in Lake Mead National Recreation Area (LMNRA) in the eastern Mojave Desert were stored dry for two years and applied to disturbed soil after a road reconstruction in LMNRA and also used in laboratory experiments to test inoculation technique effectiveness. After 18 months, field results revealed positive relationships between inoculation and the presence of macroscopic BSC cover, cyanobacteria abundance, soil stability, and ammonium concentrations. Chlorophyll fluorescence monitoring of …

The Abundance And Distribution Pattern Of Quagga Mussels In The Las Vegas Bay Of Lake Mead, Nevada And Potential Correlation With Environmental Parameters, Scott Rainville

UNLV Theses, Dissertations, Professional Papers, and Capstones

The non-native quagga mussel [Dreissena bugensis (Andrusov, 1897)] was initially discovered in Boulder Basin of Lake Mead, Nevada-Arizona on January 6, 2007. This occurrence marked the first biological invasion of dreissenid mussels in the Western U.S., following a significant North American range expansion of invasive quagga mussels from populations that invaded and colonized the Great Lakes Region in the Northeastern U.S. during 1991. This nonindigenous mollusk species quickly spread from Boulder Basin and became established throughout the entire reservoir by the end of 2007, with the exception of the inner Las Vegas Bay. There was an apparent absence of settled …

Dreissena Rostiformis Bugensis: Desiccation Of Adult Quagga Mussels Found In Lake Mead As A Preventive Measure Against Overland Dispersal In The Western United States, Matthew Kappel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The expansion of civilization across all borders of the world has proven to affect major components of ecosystems. Since the introduction and establishment of the aquatic invasive species (AIS),Dreissena rostiformis bugensis, commonly known as the quagga mussel, into the United States there has been an extensive amount of time and money spent on controlling and preventing their expansion across the United States. The quagga mussel is of major concern because of its ability to disrupt the ecological communities in previously non-infested bodies of water, which may cause a loss in biodiversity and effect environmental health. The quagga mussel has spread …

The Impact Of Creosote Bush (Larrea Tridentata) And Biological Soil Crust On Ca Distribution In Arid Soils Of The Mojave Desert, Brittany Myers

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ca is an important nutrient that plays a role in membrane stability and cell repair in plant life. This study examines the impact of creosote bush (Larrea tridentata) and biological soil crust on calcium cycling and distribution in desert soils in order to explore the use of Ca as a biosignature. Samples of creosote bush, biological soil crust and eolian dust were taken at two field sites in the Mojave Desert. The first site is located in Eldorado Valley, NV, a soil formed on a young (800-1200 years) alluvial fan deposit; the second site is located on a late Holocene-aged …

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending September 30, 2012, Margaret N. Rees

Limnological Studies

Continuation of Project 1

• The research effort titled Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay is ongoing.

Continuation of Project 2

• Additional content was contributed to the future NPS-funded U.S. Geological Survey Circular ‘state-of-the-science’ report for Lakes Mead and Mohave. UNLV performed a new co-editing and coordinating task related to this product as the major focus of this quarter’s effort; the master version of this report is on schedule for delivery to the editorial team during the first week of October 2012.

Modification Activities:

Extended Short-term Continued Limnological Assistance

Quagga Mussel Objectives:

• Most juvenile/adult quagga mussel …

Scorpion Phylogeography In The North American Aridlands, Matthew Ryan Graham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding the geographic, geologic, and climatic forces responsible for generating current patterns of biodiversity has been a central objective of phylogeography. To develop a better understanding of these processes in the North American arid lands, I used DNA sequence data and species distribution modeling to conduct three phylogeographic assessments incorporating four species of arid-adapted scorpions:Hadrurus arizonensis, H. jedediah, H. spadix,and Paruroctonus becki. In an assessment of H. arizonensis, phylogeographic patterns indicate that Pleistocene climate cycles and associated glacial refugia played a central role in structuring the genetic diversity of this species in the Mojave and Sonoran deserts, mostly supporting predictions …

Take Pride In America Phase Iii: Quarterly Progress Report, Period Covering April 25, 2012-July 24, 2012, Margaret N. Rees

Anti-littering Programs

• The GIS database continued to be populated with data.
• Hector’s Helpers added an additional youth group.
• The new website launched and social media efforts began.
• The pilot testing of the litter monitoring program continued.

The University of Nevada Las Vegas Public Lands Institute (PLI) designed the Take Pride in America (TPIA) Phase III work plan based on the strategic plan developed by the Southern Nevada Agency Partnership (SNAP) anti-litter and desert dumping team during Phase II of the program.

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending July 10, 2012, Margaret N. Rees

Walking Box Ranch

• BLM informed UNLV that after investigating a concession contract as the appropriate BLM document for the future operating partner, they have concluded that an operating agreement is the preferred document and they are proceeding to complete such an agreement as soon as possible.
• Following a visit to the ranch with BLM, UNLV has completed temporary repairs to ranch house windows, which should mitigate deterioration of the ranch house from water
• UNLV participated in a one-half day meeting with BLM to review Condit’s Extended Content Package #1. As a result of the lack of progress by Condit, UNLV was requested to …

Exploring The Seed Bank Dynamics Of Red Brome: Longevity, Density, And Relationship To Fire, Benjamin S. Jurand

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research explores several untested aspects of the seed bank characteristics of red brome (Bromus rubens), an invasive annual grass in southwestern United States arid lands. Red brome is a formidable competitor to native plant species, both annual and perennial alike, and produces many seeds that germinate easily. The stalks of red brome contribute continuous-cover fuel loads that facilitate wildfires destructive to mature native Mojave Desert plant communities. This makes it a priority species for land managers, particularly when dealing with recovery after fire.

This project addressed questions related to the longevity of red brome seeds in soil seed banks …

Investigating Three Decades Of Vegetation Change In A Mojave Desert Mountain Range, Chris Lee Roberts

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project is a vegetation change study spanning 29 years in the Newberry Mountains of Southern Nevada. Long term monitoring data are crucial for understanding the effects of climate change on vegetation dynamics. Successful management intervention in vegetation change will require identification of early indicator plant species and their responses to climatic cues. This project is one of the oldest comparisons of resurveyed Mojave vegetation community plots with repeatable methodology and the longest survey interval reported for the southeastern Mojave Desert. 103 plots were relocated and resurveyed based on data methods in Jim Holland's thesis titled "A Vegetative Analysis of …

Natural And Constructed Wetlands For Ecosystem And Engineering Services In The Arid And Semi-Arid Regions, Achyut Raj Adhikari

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Las Vegas Wash (LVW) has undergone significant wetlands degradation and soil erosion over the past thirty years due to increasing flow resulting from urbanization and large rainfall events in the Las Vegas Valley Watershed. The increased flow and associated pollution load in the LVW and its adverse impact in Lake Mead have alerted stakeholders to pay a greater attention to explore alternative measures for rehabilitation of wetland ecosystems. This dissertation, using the case of changes in LVW, analyzes and describes ecological and engineering services provided by wetlands in arid and semi-arid regions and provides a knowledge base that can …