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Environmental Monitoring

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Full-Text Articles in Desert Ecology

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending June 30, 2008, Margaret N. Rees Jun 2008

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending June 30, 2008, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Translocation program completed this quarter at current active translocation sites.
  • Egg mass surveys at Blue Point Spring conducted approximately weekly; two additional egg massed collected from site for head-starting.
  • Frogs released at Blue Point and Rogers from egg masses collected at Blue Point in March and April, further augmentations planned.
  • Spring nocturnal surveys completed.
  • Coordination for potential translocation sites on BLM lands ongoing.
  • Habitat improvements coordinated and conducted at one new translocation site on BLM lands in the Gold Butte; site received frogs in April.
  • All milestones and deliverables associated with …


An Overview Of The Vegetation Research Program: Knowledge Services For Land Management, Scott R. Abella Apr 2008

An Overview Of The Vegetation Research Program: Knowledge Services For Land Management, Scott R. Abella

Fire Science Presentations

  • Provide knowledge services about the ecology and management of southwestern dryland ecosystems
  • Specialize in working with resource managers to conduct applied research
  • Conduct and provide research, monitoring, scientific literature synthesis, and technical assistance


Plant Community Response To Fire: A Chronosequence Study, Scott R. Abella, E. Cayenne Engel Apr 2008

Plant Community Response To Fire: A Chronosequence Study, Scott R. Abella, E. Cayenne Engel

Public Policy and Leadership Faculty Research

Fires are becoming more prevalent events across the landscape in the southwestern US. Over the next several decades the already arid southwest is predicted to become warmer and drier, with longer summers, and an increase of “extreme” weather events such as lightening inducing thunderstorms. While the “hotter and drier” forecast may indicate less abundant plant life, and thus less available biomass for fuel, exotic invasive plant species are becoming more dominant across the landscape with increases in human travel and commerce. Exotic species (particularly many of the invasive grasses) are adding fuel for the fires to burn when the annuals …


Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, January 1— March 31, 2008, Margaret N. Rees Mar 2008

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, January 1— March 31, 2008, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • The Weed Sentry program surveyed 104 miles of transportation corridors on federal land in Clark County for incipient populations of exotic plants.
  • Seven manuscripts attained in-press or published status and two manuscripts were submitted for review this quarter. Among other in-press manuscripts, are one documenting Sahara mustard germination patterns (Western North American Naturalist), one assessing exotic species distributions in Clark County (Environmental Monitoring and Assessment), and another is a synthesis of burro effects on Mojave Desert vegetation (Environmental Management).
  • Staff delivered four presentations this quarter at conferences or at agency meetings. Twenty-six Las Vegas bearpoppy sites were assessed …


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2008, Margaret N. Rees Mar 2008

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2008, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Translocation program initiated this quarter, egg mass collections completed, tadpole rearing underway.
  • Egg mass surveys at Blue Point Spring conducted approximately weekly; one egg mass collected from site for headstarting.
  • Spring nocturnal surveys in progress.
  • Coordination for potential translocation sites on BLM lands ongoing.
  • Habitat improvements coordinated and conducted at one new translocation site on BLM lands in the Gold Butte; site scheduled to receive frogs in April.
  • All milestones and deliverables associated with the MSHCP project on schedule.

Project 2. Bald Eagle Winter Monitoring and Evaluation

  • Winter bald eagle count …


Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund Jan 2008

Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

1) Assessment of BLM seeding effectiveness in mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

2) Patterns driving fire recovery at the landscape scale:

  • Link initial vegetation, environment, and soils
  • Are there patterns that can be gleaned that can then be applied to management prescriptions?


Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute, Jan 2008

Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

Invasive exotic plants provide an unnatural conduit for fires in the Mojave Desert. For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a …


Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella Jan 2008

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …


Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees Dec 2007

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, October 1, 2007 To December 31, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • The Weed Sentry program surveyed more than 750 miles of federal lands in Clark County for invasive, exotic plant species.
  • Weed Sentry also removed more than 600,000 individual invasive plants from federal
    lands. These removals represent pro-active efforts that may have forestalled large
    infestations difficult and costly to eradicate.
  • In response to a request by the manager of the Fish and Wildlife Service Desert National
    Wildlife Refuge, a major effort of surveying springs for plant community composition
    and invasive plants provided unique knowledge services by the Weed Sentry program.
    No such baseline information existed for the Sheep Range. …


Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2007, Margaret N. Rees Dec 2007

Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2007, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Fall surveys completed at all natural and translocation sites.
  • Coordination for a potential translocation site on BLM lands in the Gold Butte area ongoing – the aim is that this site will be ready for translocations in 2008.
  • Coordination ongoing for evaluation of a translocation site on BLM lands in the Black Mountains, AZ – the plan is to complete compliance in 2008.
  • Coordination and assistance provided to UNLV research efforts on habitat improvements at Blue Point, Rogers, and Pupfish Refuge springs.
  • Relict Leopard Frog Conservation Team meeting held in December. …


Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Year-End Progress Report, October 1, 2006 To September 30, 2007, Margaret N. Rees Sep 2007

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Year-End Progress Report, October 1, 2006 To September 30, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • The Weed Sentry program surveyed more than 750 miles of federal lands in Clark County for invasive, exotic plant species.
  • Weed Sentry also removed more than 600,000 individual invasive plants from federal
    lands. These removals represent pro-active efforts that may have forestalled large
    infestations difficult and costly to eradicate.
  • In response to a request by the manager of the Fish and Wildlife Service Desert National
    Wildlife Refuge, a major effort of surveying springs for plant community composition
    and invasive plants provided unique knowledge services by the Weed Sentry program.
    No such baseline information existed for the Sheep Range. …


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Annual Progress Report, Period Ending September 30, 2007, Margaret N. Rees Sep 2007

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Annual Progress Report, Period Ending September 30, 2007, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Diurnal and nocturnal surveys completed at all natural and translocation sites during the spring – the most striking finding was the lack of frogs observed at Rogers Springs and lower Blue Point despite repeated survey efforts.
  • Relict leopard frog annual translocation effort completed – a total of 1365 late stage tadpoles and 592 post-metamorphic frogs from the head-start facilities were released at existing translocation sites.
  • Mark-recapture effort at Rogers Spring abandoned because of the lack of frogs; assistance provided for a mark-recapture study at upper Blue Point Spring.
  • Potential translocation sites …


Land Cover Types Of The Las Vegas Wash, Nevada, Seth A. Shanahan, Dave Silverman, Art Ehrenberg Sep 2007

Land Cover Types Of The Las Vegas Wash, Nevada, Seth A. Shanahan, Dave Silverman, Art Ehrenberg

Publications (WR)

Vegetation type, extent, continuity, and structure are some of the most important factors that determine wildlife diversity and distribution. Other contributing factors that shape wildlife communities include disturbance, competition, climate, and water availability. Because vegetation communities in the southwestern U.S. gradate sharply along zones of soil moisture, wildlife are often restricted to specific vegetation types. Along the Las Vegas Wash (Wash), Nevada, more than 250 wildlife species have been documented to occur in distinct wetland, riparian, and upland vegetation types. Recent studies have investigated the diversity and distribution of amphibians, birds, fishes, mammals, and reptiles (Shanahan 2005, 2005a, Van Dooremolen …


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending June 30, 2007, Margaret N. Rees Jun 2007

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending June 30, 2007, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Nocturnal surveys completed at all natural and translocation sites – the most striking finding was the lack of frogs observed at Rogers Springs and lower Blue Point despite repeated survey efforts.
  • Relict leopard frog annual translocation effort completed – a total of 1957 tadpoles and juvenile frogs released at six translocation sites.
  • Potential translocation sites within Gold Butte assessed during site visits in late March.
  • Coordination and assistance provided to UNLV research efforts on habitat improvements at Blue Point and Rogers Springs, and with proposed FWS actions to construct a tadpole …


Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, Period Ending March 31, 2007, Margaret N. Rees Mar 2007

Lake Mead National Recreation Area Vegetation Monitoring And Analysis: Quarterly Progress Report, Period Ending March 31, 2007, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • Weed Sentry staff surveyed for exotic species on 208 miles of roads on NPS land and on 61 miles of BLM land. Due to sparse precipitation this winter, exotic species are much less abundant this year compared to last year at this time.
  • Other exotic species projects initiated this quarter included an assessment of invasion patterns below native shrubs for early detection of potential invasion “hotspots,” and a community invasibility experiment established near the NPS nursery with substantial involvement from NPS ATR Ms. Alice Newton.
  • A manuscript detailing several experiments with the invasive species Sahara mustard was submitted …


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2007, Margaret N. Rees Mar 2007

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2007, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • Spring-time diurnal surveys for relict leopard frogs were conducted at all sites.
  • Relict leopard frog annual translocation effort was initiated. Currently, 2,153 tadpoles are being reared at the Hill Top and Willow Beach Fish Hatchery facilities. Quagga mussels found at the hatchery might not be as problematic for this program as originally thought. Current prophylactic protocols for disease treatment in tadpoles and frogs are being evaluated for their ability to kill quagga mussel larvae.
  • Coordination and monitoring was provided to EPMT crews conducting tamarisk control at relict leopard frog sites in …


Vegetation Re-Establishment Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella Jan 2007

Vegetation Re-Establishment Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella

Fire Science Presentations

Examine biotic and abiotic patterns that determine vegetative regrowth after wildfires to better inform land managers about what to expect after fires and how to manage restoration efforts.


Seeding Effectiveness For Eight Mojave Desert Perennials After A 2005 Wildfire, E. Cayenne Engel, Scott R. Abella, Christina L. Lund Jan 2007

Seeding Effectiveness For Eight Mojave Desert Perennials After A 2005 Wildfire, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

To assess BLM seeding effectiveness in a mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.


Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke Jan 2007

Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke

Civil and Environmental Engineering and Construction Faculty Research

Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this …


Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees Dec 2006

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • Two new Weed Sentry research assistants were hired.
  • Weed Sentry staff surveyed for exotic species on 89 miles of roads on NPS and BLM land and treated more than 21,000 exotic plants in incipient populations.
  • A grid-based rare plant monitoring method was tested this quarter.
  • A manuscript detailing vegetation succession on a water pipeline at Lake Mead NRA was submitted for review to the journal Crossosoma.
  • New integrative projects undertaken this quarter included establishing a competition study between a native grass and the exotic Sahara mustard, salvaging plants for research purposes from private sites with permission from landowners, …


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees Dec 2006

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending December 31, 2006, Margaret N. Rees

Wildlife Monitoring

  • Research assistant hired for Relict Leopard Frog conservation project.
  • High school minority intern hired to assist with research efforts.
  • Nocturnal visual encounter surveys for Relict Leopard Frogs conducted at all established natural sites and at 6 of 7 translocation sites.
  • Vegetation management conducted to decrease tamarisk cover along the stream at the Pupfish Refuge Spring – a Relict Leopard Frog translocation site.
  • New draft guidelines and field count protocols developed for midwinter bald eagle count.
  • Preliminary analysis and modeling of thrasher habitat selection conducted and sampling assessed
  • Call-broadcast surveys for thrasher species conducted at 43 points countywide, focusing on vegetation …


Lake Mead National Recreation Area Vegetation Monitoring And Management: Final Close-Out Report, Time Period: October 1, 2005 To September 30, 2006, Margaret N. Rees Sep 2006

Lake Mead National Recreation Area Vegetation Monitoring And Management: Final Close-Out Report, Time Period: October 1, 2005 To September 30, 2006, Margaret N. Rees

Vegetation Monitoring

The National Park Service (NPS) at Lake Mead National Recreation Area (LAME) entered into a cooperative agreement with the University of Nevada, Las Vegas (UNLV) to accomplish vegetation monitoring and management activities. This report summarizes activities that took place by UNLV under this task agreement between October 1, 2005, and September 30, 2006. The activities included:

  • Weed Sentry mapping and treating incipient populations of exotic invasive plants throughout Clark County, including along shorelines of Lakes Mead and Mohave;
  • Monitoring of targeted rare native plant species;
  • Sahara mustard research; and
  • Providing technical assistance upon request to the NPS vegetation manager.

In …


Lake Mead National Recreation Area National Park Service: Final Progress Report, Period Ending September 30, 2006, Margaret N. Rees Sep 2006

Lake Mead National Recreation Area National Park Service: Final Progress Report, Period Ending September 30, 2006, Margaret N. Rees

Wildlife Monitoring

This task agreement was awarded by the National Park Service (NPS), Lake Mead National Recreation Area (LAME), to the Public Lands Institute (PLI) at the University of Nevada, Las Vegas (UNLV) on October 1, 2005. This monitoring, research, and management project consisted of several project elements focused on: bald eagles, peregrine falcons, rare songbird species (including southwest willow flycatcher); aquatic birds, relict leopard frog, desert tortoise, and bighorn sheep. In general, actions associated with this project focused on the development and implementation of inventory and monitoring programs to determine the distribution, status, abundance, trends, and potential threats to these animals, …


Inventory And Monitoring Of Aquatic Bird Species On Lakes Mead And Mohave 2004 - 2006, Joseph Barnes Sep 2006

Inventory And Monitoring Of Aquatic Bird Species On Lakes Mead And Mohave 2004 - 2006, Joseph Barnes

Wildlife Monitoring

This project was completed as part of a task agreements awarded by the National Park Service (NPS), Lake Mead National Recreation Area (LAME), to the Public Lands Institute (PLI) at the University of Nevada, Las Vegas (UNLV). This final report was completed under a task agreement ending on September 30, 2006, and was completed in support of an NPS project funded by the Southern Nevada Public Lands Management Act (PLMA) to inventory and monitor shoreline and near-shore natural resources on Lakes Mead and Mohave (DOI 2005). This report details inventory and monitoring efforts on shoreline and aquatic bird species between …


Factors Contributing To Dust Emissions In Clark County, Nevada Quarterly Progress Report: Period Ending July 15, 2006, Margaret N. Rees Jul 2006

Factors Contributing To Dust Emissions In Clark County, Nevada Quarterly Progress Report: Period Ending July 15, 2006, Margaret N. Rees

Dust Emissions from Public Lands

  • Hiring of post-doctoral scholar is currently being finalized.
  • Modification to task agreement has been processed.


Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending June 30, 2006, Margaret N. Rees Jun 2006

Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending June 30, 2006, Margaret N. Rees

Wildlife Monitoring

  • Tortoise and tortoise habitat monitoring was conducted on the Northshore Road construction project, on the Southern Nevada Water Authority intake pipe project, the Frontier Telephone-Willow Beach project and the movie film at Temple Bar.
  • A total of 25 tortoise education classes were given to 90 individuals.
  • Evaluation of 3 potential sites for relict leopard frog translocations conducted but sites were not recommended.
  • Head-starting and translocation efforts for relict leopard frogs continued. 1183 animals translocated so far this year.
  • Relict Leopard Frog Conservation Team meeting held and yearly report completed.
  • Continuation of data management and QA of GPS collar information from …


Odonates At The Clark County Wetlands Nature Preserve: A Look At Habitat And Relative Abundance, Erin Jolley May 2006

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 Contribution Of Environmental Variables On Small Mammal Species Richness And Relative Abundance In Eastern Nevada, Stephanie Harris May 2006

The Contribution Of Environmental Variables On Small Mammal Species Richness And Relative Abundance In Eastern Nevada, Stephanie Harris

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to determine how four environmental variables: elevation, latitude, soil type, and vegetation impact the relative abundance of Peromyscus maniculatus and the species richness of small mammal populations in Eastern Nevada. In order to complete this study, a survey of small mammals was completed in the following 8 Eastern Nevada valleys: Delamar, Dry Lake, Dry Lake- Muleshoe,Cave, Lake, Snake, Spring, White River. In each valley, transects of Sherman live traps will be set up for 3 consecutive nights (O'Farrell et al 1977). Data on elevation, latitude, soil type, and vegetation were taken at each trap …


The Fate And Transport Of Nitrogen (N) And The Effect Of Emergent Plants On Natural Treatment Of N-Species At Las Vegas Wash, Nevada, Tanju Kiriscioglu May 2006

The Fate And Transport Of Nitrogen (N) And The Effect Of Emergent Plants On Natural Treatment Of N-Species At Las Vegas Wash, Nevada, Tanju Kiriscioglu

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to analyze the effect of emergent plant communities at Las Vegas Wash (the System) using a system dynamics modeling approach. Understanding the dynamics of nitrogen (N —major polluting nutrient in the Wash) that enters the System is important because it occasionally causes algal blooms, choking Lake Mead through excessive eutrophication. Emergent plant communities are an integral part of wetland ecosystems and they play a crucial role in natural treatment of nutrients. This study is intended to test this hypothesis.

The study makes use of Wash data from reliable sources (Las Vegas Valley Water District, …


Population Trends Of Wintering Bald Eagles (Haliaeetus Leucocephalus) At The Lake Mead National Recreation Area, Nevada, Deanna Morrell May 2006

Population Trends Of Wintering Bald Eagles (Haliaeetus Leucocephalus) At The Lake Mead National Recreation Area, Nevada, Deanna Morrell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to look at population trends of wintering bald eagles (Haliaeetus leucocephalus) at the Lake Mead National Recreation Area, Nevada from 1991 to 2006. Bald eagles were counted on January 5, 2006 along the entire shoreline of Lake Mead and Lake Mohave. This study focused on two questions: (1) how has the population changed over time? (2) How has the proportion of juvenile eagles to adult eagles changed over time? Question one was supported with the number of bald eagles significantly increasing (r=0.76, p=0.002). Question two was supported as the proportion of juveniles to adults …