Desert Ecology Commons^™

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 …

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending July 10, 2010, Margaret N. Rees

Walking Box Ranch

• UNLV participated in several meetings with BLM regarding updating the current Task Order, obtaining a two-year no-cost extension for the two Assistance Agreements, and to develop the future WBR operating agreement between BLM and UNLV
• UNLV met with Sara Moffatt, one of Senator Reid’s staff, to provide an update on project progress. UNLV also requested the Senator’s support in obtaining additional funding for the project for construction, and also for UNLV to bridge the transition from construction through the first two years of operation.
• UNLV held several internal meetings to advance planning for a July VA meeting with BLM to …

Mojave Applied Ecology Notes Summer 2011, Scott R. Abella, Charles W. Denton, David G. Brewer, Rory W. Steinke, Wayne A. Robbie, W. Wallace Covington, E. Cayenne Engel, Ross Guida

Mojave Applied Ecology Notes

Thoughts on fire possibilities on Mount Charleston, estimating historical densities of Ponderosa pine in northern AZ, over-understory changes in the Spring Mountains, seeding effectiveness in Red Rock Canyon, workshop announcements.

The Effects Of Social Context And Cache Survival On Pinyon Jay Caching Behavior, Christine L. Keefe

School of Biological Sciences: Dissertations, Theses, and Student Research

I examined how pinyon jays (Gymnorhinus cyanocephalus) assess and determine the risk of pilferage to their caches. Jays were allowed to cache in an open room while alone or while being observed by a conspecific. In a counterbalanced design, jays cached in the opposite treatment once they had finished recovering their caches. I compared birds’ behaviors between treatments in order to determine whether jays consider the presence of an observer in measuring the local competitive environment. Once all jays had completed alone- and observed- treatments, I ran the experiment once more to determine if individuals were consistent in …

Relationships Of Exotic Plant Invasions With Biological Soil Crust, Desert Pavement, And Soil Carbon In The Eastern Mojave Desert, Adria Decorte

UNLV Theses, Dissertations, Professional Papers, and Capstones

In a matter of 50 years, exotic annual plants have become widespread in the Mojave Desert, contributing to drastic landscape changes such as those caused by recent fires. Invasions by exotics threaten native Mojave Desert plant communities by altering community functions (e.g. fire regimes) and by reducing plant diversity. Because it is not practical, or even possible, to eradicate these exotics, developing effective prevention techniques is the key to controlling these invasions.

This thesis used a greenhouse experiment, a field experiment, and a correlational field study to examine the affect soil surface types have on the establishment of three exotic …

Estimating Wildfire Potential On A Mojave Desert Landscape Using Remote Sensing And Field Sampling, Peter F. Van Linn Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

Landscape level wildfire prediction can be used to allocate wildfire resources and guide land management practices. Wildfire prediction in arid habitats in the Southwestern United States is of specific concern because of the negative ecological impacts of fire on desert habitats and the current lack of accurate fire prediction tools for such areas. This study examines the ability to predict previous fire occurrences and estimate future fire potential using satellite imagery and on the ground field survey techniques along with ignition potential data (lightning strikes and distance to roads), topographical data (elevation and aspect), and climate information (maximum and minimum …

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. …

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 …

Phylogeography Of Three Heteromyid Taxa: Insight On The Evolution Of A North American Arid Grassland Rodent Guild, Sean A. Neiswenter

UNLV Theses, Dissertations, Professional Papers, and Capstones

Revealing how communities are shaped by abiotic and biotic factors plays a central role in biogeographic and comparative phylogeographic studies. The biogeography of North American arid grasslands is explored using nuclear and mitochondrial DNA from three groups of heteromyid rodents that are broadly sympatric in aridlands across western North America. Phylogenetic and molecular clock analyses are used to estimate the timing of divergences within each group. A general pattern of late Miocene divergence and expansion of lineages in each of the groups that is coincident with the rapid expansion of arid grasslands at the time. The initial divergence is followed …

Oral Presentation: Plant Genes And Drought Tolerance, Norris Lam

Festival of Communities: UG Symposium (Posters)

Research has shown that a gene from C3 xerophyte Larrea tridentata (creosote bush), LtWRKY21, is involved in pathways governing creosote bush’s high tolerance to environmental stress. By understanding the way in which creosote bush adapts to drought, crop plants can be engineered to be more drought tolerant during times of imminent global climate change. To study the underlying mechanisms of creosote bush drought response, the LtWRKY21 gene was mobilized into the model organism Arabidopsis thaliana. Chlorophyll degradation, cellular electrolyte leakage, and water content in leaves will serve as indicators of drought tolerance in LtWRKY21-transgenic A. thaliana after treatment in chemically …

Review Of The Ecology And Management Of Prairies In The Central United States. By Chris Helzer., David J. Gibson

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

This relatively short book is an informative and easyto- read account of the author's philosophy and advice on how to manage prairies in the Central U.S., an area corresponding to the eastern portion of the Great Plains where tall- and mixed-grass prairie occurred. With fragmentation and huge losses of this region's natural prairie habitat, there is a growing appreciation for active management of remnants and prairie restoration. This book provides an excellent introduction to this topic.

Mojave Applied Ecology Notes Spring 2011, Scott R. Abella, Ross Guida, S. D. Smith, Christopher L. Roberts, Haroon Stephen, William J. Smith, Zhongwei Liu, James S. Holland, Aurore Giguet

Mojave Applied Ecology Notes

Red brome distribution in the eastern Mojave Desert, A look at the UNLV xeric gardens and Marjorie Barrick museum, Summary of recent science synthesis efforts

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Final Project Report, Margaret N. Rees, Jef R. Jaeger Ph.D.

Wildlife Monitoring

This task agreement was originally awarded by the National Park Service (NPS), Lake Mead National Recreation Area (LMNRA) to the Public Lands Institute at the University of Nevada, Las Vegas on September 30, 2006, and was amended to run through March 31, 2011. This agreement covered several project elements focused on:

• Monitoring and conservation actions for the relict leopard frog
• Coordinating and conducting annual bald eagle counts on Lakes Mead and Mohave
• Development and assessment of a habitat map for wintering bald eagles based on observations data collected during winter counts

• Monitoring of breeding peregrine falcons and assessment of reproductive …

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending January 10, 2011, Margaret N. Rees

Walking Box Ranch

• UNLV participated in three project workshops and one additional meeting to assist in planning and design of the future WBR museum and field/research station.
• Weather station progress included design of programming software that will provide past weather information to website user, two abstracts have been submitted to an energy sustainability meeting, and a paper reviewing energy efficient building envelope components has been prepared and submitted for publication.
• Work has begun on a new education project titled “Multimedia Field Guides for Public Engagement at Walking Box Ranch, Mojave Desert.” The project will develop and disseminate a modern geological and environmental field …

Environmental Factors Affecting Settlement Of Quagga Mussel (Dreissena Rostriformis Bugensis) Veligers In Lake Mead, Nevada-Arizona, Usa, Dong Chen, Shawn Gerstenberger, Sara Ann Mueting, Wai Hing Wong

Environmental & Global Health Faculty Research

Environmental factors that can affect the settlement rate of quagga mussel veligers include flow velocity, water temperature, pH, dissolved oxygen (DO), conductivity, total organic carbon (TOC), and the surface roughness of monitoring substrates. In the present study, six artificial substrates, Acrylonitrile Butadiene Styrene (ABS) plastic, High Density Polyethylene (HDPE) plastic, Concrete Underlayment Board (CUB), aluminum, stainless steel and fiberglass, were used to monitor the settlement of quagga mussel veligers at different water depths in Lake Mead, Nevada-Arizona, USA. Considering the hierarchical data structure of observed mussel densities, we investigated the relationship between mussel settlement on monitoring substrates and the surrounding …

Mojave Applied Ecology Notes Winter 2011, Scott R. Abella, Alice C. Newton, Kenneth Chittick, Pam Sinanian

Mojave Applied Ecology Notes

Lake Mead’s collaborative applied science research program; “annoying the elephant” - ruminations on active management by Alice Newton, Lake Mead NRA vegetation manager; 2012 NWRA Lake Mead symposium sneak peak; assessing forest change using dendrochronology in the Spring Mountains.

Can Resource-Use Traits Predict Native Vs. Exotic Plant Success In Carbon Amended Soils?, Robert J. Steers, Jennifer L. Funk, Edith B. Allen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Productivity in desert ecosystems is primarily limited by water followed by nitrogen availability. In the deserts of southern California, nitrogen additions have increased invasive annual plant abundance. Similar findings from other ecosystems have led to a general acceptance that invasive plants, especially annual grasses, are nitrophilous. Consequently, reductions of soil nitrogen via carbon amendments have been conducted by many researchers in a variety of ecosystems in order to disproportionately lower invasive species abundance, but with mixed success. Recent studies suggest that resource-use traits may predict the efficacy of such resource manipulations; however, this theory remains largely untested. We report findings …

Spatio-Temporal Variations In Soil Moisture And Physicochemical Properties Of A Typical Semiarid Sand-Meadow-Desert Landscape As Influenced By Land Use, L. Duan, T. Liu, X. Wang, G. Wang, L. Ma, Y. Luo

Civil & Environmental Engineering Faculty Publications

A good understanding of the interrelations between land cover alteration and changes in hydrologic conditions (e.g., soil moisture) as well as soil physicochemical properties (e.g., fine soil particles and nutrients) is crucial for maintaining the fragile hydrologic and environmental conditions of semiarid land, such as the Horqin Sandy Land in China, but is lacking in existing literature. The objectives of this study were to examine: (1) spatio-temporal variations of soil moisture and physicochemical properties in semiarid land; and (2) how those variations are influenced by land cover alteration. Using the data collected in a 9.71 km2 well-instrumented area of the …

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending December 31, 2010, Margaret N. Rees

Wildlife Monitoring

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

• Final milestones and deliverables for this project were completed this quarter.
• Fall monitoring surveys were completed at all sites.
• Habitat actions to improve breeding pools were conducted at one site.
• Data and associated metadata were compiled and quality assured.
• Final and annual reports were written and submitted in required formats for Clark County

and the Relict Leopard Frog Conservation Team.

Project 2. Bald Eagle Winter Monitoring and Evaluation

• This project was previously completed and all associated deliverables met.
• Efforts were provided this quarter in support of the 2011 winter count.

Project …

Effect Of Spatial And Temporal Variability Of Antecedent Moisture Content On Model-Generated Runoff From An Arid Watershed, William J. Meyer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Streams in the arid southwest are typically ephemeral, and stream gages are not commonly available. Consequently, runoff data from storm events is not available, and flood control facility design or other water resource related decisions are based on synthetic hydrographs. In the Mojave Desert region of Southern Nevada, the duration of storm used to develop these synthetic hydrographs is the 6 hour storm. The 6 hour storm is used to simulate high intensity summer storms. Additionally, soils information used in the calculations for these synthetic hydrographs is taken from maps that are generally developed for a broad range of issues …