Environmental Sciences Commons^™

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, …

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 …

The Hospitality Industry’S Response To Climate Change: Is The Response Sufficient?, Paul Michael Carlson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to explore the serious consequences that global warming and climate change pose for the planet and its inhabitants, and to shed light on the hospitality industry’s contribution to the problem. The study further sought to examine whether the hospitality industry is doing their part in implementing “green” programs to combat its negative contribution to climate change.

Environmental Impact Of The Three Kids Mine Tailings, Henderson, Nv, Ji Hye Park

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focused on the distribution of the Three Kids Mine tailings in surface soils in and around the mine in Henderson, Nevada. It is situated next to the communities of Calico Ridge and Lake Las Vegas Resort, and, just the west of the Lake Mead Recreation area. Even though the mine has been inactive for almost 50 years (1917-1961), tailing piles and other sources of contamination on the mine are currently exposed to the atmosphere. In this study, surface soil samples were collected along eight transects emanating from the center of Three Kids Mine tailing piles up to five …

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 …

Climate And Vegetation Change In The Newberry Mountains, Southern Clark County, Nevada, Ross Joseph Guida

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ecological studies have shown worldwide that vegetation is being affected by climate change. Species are shifting to new elevations and physiographic positions to adapt to changes in their environment. More specifically, paleoecology studies in the Mojave Desert have shown shifting vegetation patterns in response to past warming and precipitation changes. Recent studies have shown mortality among desert plants related to extended drought and warming. However, few studies have shown how the geographic distribution of Mojave Desert species has changed during this most recent period of warming. This study addresses this gap in the literature by focusing on several plant species …

Assessing A Combined Theories Approach To Climate Change Communication, Ted Greenhalgh

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research examines the complexities of communicating climate change risk information and the underlying individual attitudes and message content that affect message reception. Using climate change messages incorporating fear appeals and normative information subject's reactions to the messages were evaluated using the Theory of Planned Behavior model. The study found that fear appeals did increase behavioral intention to adopt a lower carbon lifestyle among test group subjects. The Theory of Planned Behavior model showed that attitudes and self-efficacy were significant predictors of the behavioral intent to adopt a lower carbon lifestyle, while community norms were only marginally predictive. However, not …

Effectiveness Of Earthtec ® On Killing Invasive Quagga Mussels (Dreissena Rostriformis Bugenis) And Preventing Their Colonization In The Western U.S., Ashlie Watters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dreissena rostriformis bugensis, an invasive species, also known as the quagga mussel, was discovered in Lake Mead, NV in January of 2007. In the four years since detection, quagga mussels have created tremendous economical, ecological, and human health impacts. The mussels clog pipes, ruin boat motors, and damage recreational equipment, and once established in the lake, routine maintenance is necessary to avoid further damage. Because of quagga mussels' high fecundity, planktonic veliger stage, and ability to attach to substrates with byssal threads, they have easily and swiftly spread to other lakes and reservoirs in the Lower Colorado River Basin. …

Impacts Of Climate Change And Weather Modification On Hydrologic Characteristics Of Watersheds In The Western United States, Anil Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research quantifies the impacts of climate change and weather modification (WM) on hydrologic characteristics of watersheds in the arid regions of the western United States. This research performs a long-term simulation of streamflow for present and future climate conditions in the North Platte (NP) Watershed, Wyoming; a shorter duration simulation is then performed to observe the likely impacts of event based changes in an urban watershed in Las Vegas, Nevada.

First, a study is carried out in Chapter 3 that evaluates the impacts of WM on water supply by developing a hydrologic model for the NP Watershed. The variable …

Colonization And Decontamination Of Quagga Mussels In The Western United States: Monitoring Veligers In Lake Mead And Field Testing In The Effects Of Hot-Water Spray As A Means Of Watercraft Decontamination, Sean Robin Comeau

UNLV Theses, Dissertations, Professional Papers, and Capstones

The introduction and establishment of aquatic invasive species (AIS) is one of the top causes of global biodiversity loss and ecological change, and is also financially costly for taxpayers and agencies managing protected areas. This is especially true regarding the nationwide spread of dreissenid mussels to various bodies of freshwater. The discovery of invasive quagga mussels (Dreissena rostriformis bugensis) in Lake Mead on January 6, 2007 has changed the popular recreation area into a potential vector of the destructive AIS. This location could allow for an increased spread of these dressenid species to uninfested bodies of water in the western …

An Ecological Study Of Peregrine Falcons (Falco Peregrinus) At Lake Mead National Recreation Area, 2006-2010, Joseph Graham Barnes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Peregrine Falcons (Falco peregrinus) represent an encouraging conservation biology success story in North America during the twentieth century. Their distribution and population size suffered major restrictions after the initiation of widespread application of the synthetic pesticide dichloro-diphenyl-trichloroethane (DDT) within the U.S. in the 1940s. The species was federally listed as endangered in the U.S. in 1969 and was then delisted in 1999 after DDT was banned in 1972. Herein, I present my ecological research of peregrines within Lake Mead National Recreation Area (LMNRA), concentrating on the years 2006-2010. This thesis is comprised of two chapters. In the first chapter, I …

Evidence Of An Active Enso And Pdq During The Mid-Holocene From A Costa Rican Speleothem, April D. Azouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although the El Nino/Southern Oscillation (ENSO) is the most important source of inter-annual climate variability in the tropics, its Holocene history is poorly understood, particularly in Central America. A high resolution (-3.8 years/sample) paleoclimate record of Central American rainfall variability has been reconstructed from a U /Th-dated stalagmite (7890 to 6490 yrs B.P.) from Costa Rica to constrain the onset and variability of ENSO throughout the Holocene, and to determine its role in generating regional climate anomalies. I suggest drier conditions, forced by El Nino, are represented by higher 5180 values, and are correlative with higher 513C values, indicating that …

Odonates At The Clark County Wetlands Nature Preserve: A Look At Habitat And Relative Abundance, Erin Jolley

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to identify the various species, relative abundance and habitat of dragonfly and damselfly larvae at the Clark County Wetlands Park Nature Preserve (WPNP). An accurate assessment of these insects can be useful in interpreting potential indications of environmental problems at the Wetlands. From this data, necessary improvements can be made to the dragonfly habitat as well as the habitat of other surrounding organisms. Habitat identification is considered especially important because it is "structured by instream and surrounding topographical features, and is a major determinant of aquatic community potential" (Southwood, 1977). For purposes of this …

The Effects Of Off-Road Vehicle Use In Desert Tortoise (Gopherus Agassizii) Habitats, Brent D. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The desert tortoise (Gopherus agassizii) populations have been in decline and have been placed on the endangered species list. No single factor is ultimately responsible for the tortoise decline. It is a combination of events that collectively have a negative impact. I chose to focus my study on only one factor, off-road vehicles. By evaluating the damage done to the terrain by off-road vehicles, a better understanding of their impact on the tortoise populations can be assessed and protective measures taken.

The amount of available vegetation does not seem to play a role in their decisions of which plants to …

Defining Soil Type And Habitat Characteristics Of The Arctomecon Californica, Philip S. Childers

UNLV Theses, Dissertations, Professional Papers, and Capstones

A. californica can be considered a rare endemic species, which is believed to be restricted by unique soil relationships. These relationships make the species vulnerable to anthropogenic habitat disturbance. Although A. californica is listed as critically endangered by the state of Nevada, further research is needed before the species can be listed as federally endangered or threatened. This study used primary observational data and secondary GIS compatible data to characterize A. californica habitat. Representative sampling techniques were used to select observations from derived soil types. Although a majority of A. californica populations were found to occur in gypsic soil types, …

The Effects Of Environmentally Relevant Doses Of Perchlorate (Clo4-) On Rana Pipiens Metamorphosis And Development, Andrea N. Golli

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to assess the effects of environmentally relevant concentrations of perchlorate on the development and growth of Rana pipiens. Ammonium perchlorate is a rocket fuel oxidizer that is known to interfere with the function of the thyroid gland and some of the highest United States surface water concentration exists in the Las Vegas Wash, NV. Perchlorate not only blocks the body’s ability to incorporate iodine into T3 and T4 hormones through the sodium iodine symporter system, but also depletes the thyroid glands’ internal stores of iodine. Many of the steps that regulate metamorphosis in amphibians …

Fluctuations In Chinook Salmon (Oncorhynchus Tshawytscha) Counts At Three Lower Columbia River Spawning Sites, Eric Michael Loomis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Several hypotheses were developed to explore the pronounced increase in Chinook salmon (Oncorhynchus tshawytscha) returning to spawning grounds at the Cowlitz, Kalama, and Lewis Rivers, three tributaries of the lower Columbia River. The study was conducted using data compiled over a ten-year span from 1991-2001. Preliminary indications are that trends in climate are linked to these increases, with the absence of El Niño events and fluctuations in winter precipitation as likely explanations of these phenomena. The unique nature of Chinook life cycles causes them to utilize a variety of habitats that require ideal conditions for maximum survival rates. Correlations between …

Assessment Of Potential Environmental Impacts Of Nature-Based Tours Originating Within Clark County, Nevada, Beth Domowicz

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this thesis was to assess the potential magnitude of negative environmental damage of nature-based tours originating in Clark County, Nevada. An ordinal ranking system was used for assessment of five variables. These variables were resource use, noise pollution, soil degradation, vegetation degradation, and wildlife disturbance. There were two proposed answers. The first was that as distance increased, negative tour impact would increase. This was not supported, since tours had high impacts for destinations that were close by and far away. The second was that most tours were not causing high damage to the environment. This hypothesis was …

Remote Sensing And Geographic Information Systems For Decision Analysis In Public Resource Administration: Case Study In A Southwestern Watershed, William G. Kepner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alternative futures analysis is a scenario-based approach to regional land planning that attempts to synthesize existing scientific information in a format useful to community decision makers. Typically, this approach attempts to investigate the impacts of several alternative sets of choices preferred by representative stakeholder groups relative to selected environmental or economical endpoints. Potential impacts from each of the scenarios are compared to current conditions of the region in terms of a set of processes that are modeled within a geographic information system. Future conditions are generally examined from the perspective of a recent baseline condition (versus empirically determined using a …

Two Different Soil Sampling Techniques For Assessing Soil Lead Concentrations At The Overton Wildlife Management Area, Nevada, Kristen E. Falc

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the summer of 1999, soil samples were taken from the Overton Wildlife Management Area (OWMA), located in the Moapa Valley of Clark County, Nevada. Although lead shot has been banned for the hunting of waterfowl since 1986, it is still legal for upland game hunting. The field sampled serves primarily as a dove hunting area and is cultivated. A large sample size was taken to indicate the short-term effects of the deposition of lead shot in the area and a small sample size, the long-term. Lead shot was recovered from 64% of the small samples and the estimated concentration …

Mapping The Boulder City Wetlands Using A Global Positioning System (Gps) And A Geographic Information System (Gis), Jennifer Lea Bishop

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Boulder City Wetlands is a constructed wetlands park located in Boulder City, Nevada, approximately 23 miles southeast of Las Vegas, Nevada. Currently, a baseline study of water quality is being conducted in the Boulder City Wetlands. This baseline study of the wetlands is an important step in understanding the development of the Boulder City Wetlands over time. As wastewater is eventually introduced into the existing community tap water running through the wetlands, it is expected that the nitrogen within the water will enhance the growth of vegetation in the surrounding area. Comparing the vegetation growth over time is only …

Lead Shot Concentration In Soil At The Overton Wildlife Management Area, Nevada, George R. Bertoty

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the spring of 1998, soil samples were collected from two areas at the Overton Wildlife Management Area (OWMA), located in the Moapa Valley of Clark County, Nevada. Lead shot has been banned for the hunting of waterfowl since 1986 but is still legal for upland game hunting. Both types of hunting occur at OWMA. One area sampled is a cultivated field and serves primarily as a dove hunting area. The other area is primarily a waterfowl hunting area and is flooded during the waterfowl-hunting season. Lead shot was recovered from 83% of the samples from the dove hunting area, …

A Strategic Analysis Of The Rocky Flats Cleanup, Patrick Mccann

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Rocky Flats Environmental Technology Site is located in Golden, Colorado. It is situated on 384 acres in a 6,550-acre natural preserve. Rocky Flats ended its original mission in 1989, after raids on the site by both the FBI and the EPA for illegal dumping and other environmental violations. Since then the site has been scheduled for cleanup. This thesis will provide background information on the site and on the company hired to perform the cleanup. It also provides an evaluation of some key policies regarding the cleanup procedures. Since the end of the cold war, the production of nuclear …

A Comparison Of Astm Standard E1599-94 And A Site Assessment Project Located In North Las Vegas, Kenneth Anthony Katsuda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This document provides a comparison of ASTM E-1599-94 Standard for a petroleum release and the procedures performed on a site assessment project in North Las Vegas. The major elements of a site assessment are thoroughly discussed in this document. They elements consist of the Initial Site Assessment, On-Site Delineation, Off-Site Delineation, Sampling/Analysis, and Site Assessment Methodologies.

The data was obtained through extensive research, utilizing reference documents,on-site experience, and the knowledge of Keith Stewart of Stewart Environmental.

After reviewing and comparing the data of my research, the procedures applied to the North Las Vegas Site (NLVS) were quite similar to the …

The Use Of Spectrofluorimetry And Capillary Electrophoresis/Laser-Induced Fluorescence For The Detection Of Fluorescent Dyes In Groundwater Migration Studies, Patrick Ferguson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis involves work that was accomplished during a two-year internship at the Environmental Protection Agency's (EPA), Environmental Chemistry Branch. The research is an application of trace level determination of fluorescein dyes used as groundwater tracers. The work was performed to determine whether groundwater could migrate from a Resource Conservation Recovery Act (RCRA) site to an adjacent Superfund site. The research involved using Spectrofluorimetry and a new technique called capillary electrophoresis/laser induced fluorescence (CE/LIF) to determine tracer dyes that were injected at the RCRA site and monitored at the Superfund site. Results from Spectrofluorimetry were compared to those of CE/LIF. …

Blm Rangeland: Has The Condition Improved?, Angela C. Dudley

UNLV Theses, Dissertations, Professional Papers, and Capstones

"Whose Home Is the Range, Anyway?: The latest research is confirming that in the West's fragile public lands, cattle are often bad news for wildlife." This is the title and headline of Lisa Drew's article in the December/January 1994 issue of National Wildlife. It shows a picture of what looks like a wasteland with only cattle, manure and a fence, no vegetation (Drew, 1994). Inside the article, Drew quotes biologist Bob Ohmart at Arizona State University's Center for Environmental Studies as saying, "Livestock grazing is without a doubt the greatest threat to western wildlife" (p. 15). Drew contends that, "The …