Desert Ecology Commons^™

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 …

Refining Thresholds In Coupled Fire–Vegetation Models To Improve Management Of Encroaching Woody Plants In Grasslands, Dirac L. Twidwell Jr, Samuel D. Fuhlendorf, Charles A. Taylor Jr, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

1. Restoration priorities are typically established without quantitative information on how to overcome the thresholds that preclude successful restoration of desirable ecosystem properties and services. We seek to demonstrate that quantifying ecological thresholds and incorporating them into management-oriented frameworks provide a more comprehensive perspective on how the threshold concept can be applied to achieve restoration goals.

2. As an example, restoration actions have been largely unsuccessful when based on prevailing ecological knowledge of fire-based thresholds in nonresprouting Juniperus woodland. We build on previous threshold-based research and link well-established models from applied fire physics with a widely applied ecological positive feedback …

Review Of Conspecific Attraction And Area Sensitivity Of Grassland Birds, David R.W. Bruinsma, Nicola Koper

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

Many species of grassland birds are area sensitive, which may exacerbate the ecological effects of the extensive loss and fragmentation of grasslands that has taken place across the northern Great Plains. However, the reasons for this area sensitivity are unclear, as vegetation structure, matrix composition, and restriction of movements among patches do not seem to provide viable explanations for species native to grasslands. Con specific attraction, whereby species are behaviorally stimulated to select habitat or establish territories near individuals of the same species, may help explain this area sensitivity. We review and discuss theoretical and empirical research on avian conspecific …

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 …

Comparative Study Of Constituents Of Essential Oils Of Ocimum Basilicum L. Cultivated In The Mongolian Gobi, Shataryn Altantsetseg, Sandui Shatar, N. Javzmaa

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The essential oils of the herb Ocimum basilicum L., cultivated in the Mongolian Gobi, have been examined. Oils were isolated by hydro-distillation and analyzed by GC-MS. The principle components of Common Basil were methyl chavicol (52.1 %), linalool (23.9 %). In the oils of the different varieties of Basil were the following compounds found: Sweet Basil: linalool (24.5–27.4 %), methyl chavicol (19.8–20.0 %), bergamotene (10.0 %), 1.8-cineole (8.5 %); Purple Basil: linalool (52.8 %), 1.8-cineole (8.7 %); Cinnamon Basil: methyl chavicol (60.4 %), 1.8-cine-ole (6.3 %), linalool (3.3 %) and cadinol (3.2 %); Italian large leaf Basil …

Herpetological Diversity Of Mongolia And Its Conservation Issues, Khorloo Munkhbayar, M, Munkhbaatar

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

From the viewpoint of evolution, the classes of amphibians and reptiles could be considered as relicts, and because they are poikilothermic animals, it’s very difficult for these species to live under the dry and cold climatic conditions in Mongolia. Even species diversity is poor, Mongolian herpetological composition is unique, highly adopted to the country’s harsh climate and originated a long time ago.

In Mongolia, six species of amphibians belong to four genera, four families and two orders and the recorded 21 species of reptiles belong to 13 genera in six families of two suborders.

Structure And Productivity Of Haloxylon Ammodendron Communities In The Mongolian Gobi, Tamara I. Kazantseva, Nikolay N. Slemnev, Pjotr D. Gunin, Sh. Tsooj

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Communities of Haloxylon ammodendron are widespread in the Mongolian Gobi where they play a significant role in biodiversity preservation. They occupy several main types of habitats, showing differences in density, projective cover, and productivity. Haloxylon ammodendron plays a similar, if not even more important role in the arid zone of Mongolia as the principal forest-making trees in the Northern part of the country. The complex set of quantitative parameters of Haloxylon ammodendron stands studied here in respect to temporal dynamics can serve as an indicator of both the vitality of desert ecosystems, and of environmental change.

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 …

Effects Of Climate Change On Spring Ecosystem Hydroecology As A Guide To Developing Alternative Water Policies, Scott Mensing, Saxon E. Sharpe, Scott Bassett, Don Sada, Jim Thomas

Climate Change Seminar Series (NNE)

Hydroecology: the interface of ecological systems and water which combines the scientific disciplines of hydrology and ecology

Goal: evaluate the hydrologic and climate history using pollen, loss on ignition, total inorganic carbon, and invertebrates from spring sediments in Spring Valley, Eastern Nevada and Snake Valley, Western Utah

Review Of Grass: In Search Of Human Habitat. By Joe C. Truett. Foreword By Harry W. Greene., Mary Ann Vinton

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

Much of the book is devoted to discussing the heavy human dependence on grasslands and whether this relationship can be maintained in company with grassland conservation. Can humans continue to use grasslands for food, fiber, and newer uses like biofuels and carbon banking while still sustaining the ecosystem? Many of us in academic ecology struggle with resolving perceived conflicts between conservation and human grassland use. In many cases, a "win-win" scenario exists in which, for example, the proper use of livestock grazing is perfectly compatible with a healthy grassland ecosystem. In other cases, such as conserving prairie dog populations, tensions …

The Use Of Chloramines To Eradicate Quagga Mussel Larvae, Trea Lacroix, Kumud Acharya

Undergraduate Research Opportunities Program (UROP)

Quagga Mussels, Dressenia bugensis, are a growing problem in the western United States, particularly in their ability to infest underwater infrastructures and clog water intake pipes and screens of power and treatment plants. Chlorine has been found to be the most effective chemical to get rid of veligers (planktonic larval form of quagga mussels) in the pipes. However, chlorine leaves a residue called trihalomethane, which is a carcinogen at higher concentrations. The purpose of this project is to test the effectiveness of an alternate chemical, chloramines (chlorine and ammonia), which leaves behind little to no residual trihalomethane. Upon experimentation with …

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. …

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.

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 …

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 …

Reconstructing Species Responses To Past Climatic Changes Using Niche Modeling And Genetic Data, Tereza Jezkova

UNLV Theses, Dissertations, Professional Papers, and Capstones

Glacial – interglacial cycles have a pronounced impact on species distributions and genetic structure. Many species shift their distributions to lower latitudes and altitudes during the colder glacial periods and expand northwards and up the elevation during warmer interglacial periods. Some species however are capable of adapting to changing environment which allows them to persist in place despite climatic changes. I explored how climatic changes after the last glacial maximum (LGM) effected two species inhabiting the deserts of western North America: one mammal (Chisel-toothed Kangaroo Rat, Dipodomys microps) and one reptile (Desert Horned Lizard, Phrynosoma platyrhinos). I used …

New Mexico Environmental Flows Workshop Report And Synthesis, From The Environmental Flows Workshop At The University Of New Mexico School Of Law March 15, 2010, Utton Transboundary Resources Center, Unm, Adrian Oglesby

Publications

This report is a synthesis of the presentations and discussions featured at the Utton Transboundary Re-sources Center’s March 15, 2010 Environmental Flows Workshop at the University of New Mexico School of Law. Over 100 stakeholders, lawyers, scientists, and decision-makers gathered to develop a better understanding of how environmental flows are successfully implemented across the West and in New Mexico. They also began the process of evaluating the condition of New Mexico’s rivers and identifying opportunities to conserve and enhance their natural functions.

The goal of the Workshop was to inform a wide range of policy-makers, agency managers and stakeholders of …

Temporal Dynamics Of Group Size And Sexual Segregation In Ibex, N. J. Singh, S. Amgalanbaatar, Richard P. Reading

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Group size is an important variable describing behavioral ecology of animals. A variety of factors such as habitat characteristics, life history, spatio-temporal resource dynamics, population density, predation risk, competition with kin, and social learning often determine group size in large mammals. We studied temporal dynamics of group size in Siberian ibex (Capra sibirica) in a protected area in Mongolia. We measured monthly and yearly variations in typical group size and used the sexual segregation and aggregation statistic to assess sexual segregation. Ibex formed the largest groups in November and smallest groups in July. However, group sizes did not …

An Inventory And Condition Survey Of The Western Australian Part Of The Nullarbor Region, Peter-Jon A. Waddell, A K. Gardner, P Hennig

Technical Bulletins

The inventory and condition survey of the Western Australian part of the Nullarbor region, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2005 and 2007, describes and maps the natural resources of the region. This survey report provides a baseline record of the existence and condition of the area's natural resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The Nullarbor region has …

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Report, Period Ending September 30, 2009, Margaret N. Rees

Limnological Studies

Project 1: Two advisory team meetings were attended this year; technical input was provided as appropriate; and summaries were prepared and delivered to Kent Turner. The SCOP Selenium Management Plan has been reviewed with two reports provided.

Project 2: Whitepapers on the carp die-off due to Koi Herpes Virus (KHV) and on lead-base paint use on launch ramps were finalized and delivered to Mr. Turner.

Project 3: The Interagency Monitoring Action Plan (I-MAP) for Quagga Mussels has been approved for implementation.

Project 5: Seven articles based on presentations at the Lake Mead Science Symposium have been approved by the technical …

Distribution And Site Selection Of Le Conte's And Crissal Thrashers In The Mojave Desert: A Multi-Model Approach, Dawn Marie Fletcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Information on the distribution and habitat requirements of a species are critical components to the development of meaningful conservation plans. Such knowledge, however, is particularly difficult to obtain for species that are elusive and occur at low densities, such as the Le Conte's ( Toxostoma lecontei ) and Crissal (Toxostoma crissale ) thrashers. In association with a regional conservation plan, I evaluated the distribution and habitat selection of these thrashers within Clark County, Nevada in the eastern Mojave Desert. I used a call-broadcast approach to sample 432 stratified random locations, detecting Le Conte's thrashers at 45 locations and Crissal …

An Inventory And Condition Survey Of The Lower Murchison River Area, Western Australia, P Hennig

Technical Bulletins

The inventory and condition survey of the lower Murchison River area, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2002 and 2003, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. This survey report presents …

Early Post-Fire Recovery On A Heavily Visited Mojave Desert Burn: Red Rock Canyon Near Las Vegas, Nevada, Scott R. Abella, E. Cayenne Engel, Christina L. Lund, Jessica E. Spencer

Fire Science Presentations

Wildfire has become widespread in southwestern USA deserts. In a record 2005 fire season in the Mojave Desert, for example, more than 385,000 hectares burned (Brooks and Matchett 2006). This burned area is approximately 3% of the entire Mojave Desert. Fueled in large part by exotic annual grasses, these fires burned desert ecosystems thought to have only burned infrequently historically. Burns now occupy significant portions of desert landscapes, posing prominent management challenges. Improving our understanding of plant recovery on desert burns is important for evaluating future fire hazard, whether natural revegetation will meet management objectives, and for planning active revegetation …

Post-Fire Plant Recovery In The Mojave And Sonoran Deserts Of Western North America, Scott R. Abella, Public Lands Institute, Department Of Environmental Studies, University Of Nevada, Las Vegas

Fire Science Presentations

Fire is thought to have been generally rare historically in the Mojave and Sonoran Deserts. However, invasion by exotic grasses (e.g., Schismus spp.) has increased fuel continuity, promoting fire in these deserts. Succession and recovery are not well understood processes in deserts, nonetheless for a novel disturbance like fire. In addition to helping build theories of desert succession and recovery, information on post-fire recovery has numerous practical implications (e.g., determining whether active revegetation is needed). Systematic reviews provide a means for obtaining literature using reproducible search criteria. This approach facilitates a balanced appraisal of available information, synthesizes scattered literature, and …

Consequences Of More Extreme Precipitation Regimes For Terrestrial Ecosystems, S. D. Smith, C. Beier, Aimee T. Classen, Melinda D. Smith, Jana L. Heisler, S. W. Leavitt, Alan K. Knapp, D. Briske, Y. Luo, M. Reichstein, J. E. Bell, Philip A. Fay, R. Sherry, Benjamin Smith

Life Sciences Faculty Research

Amplification of the hydrological cycle as a consequence of global warming is forecast to lead to more extreme intra-annual precipitation regimes characterized by larger rainfall events and longer intervals between events. We present a conceptual framework, based on past investigations and ecological theory, for predicting the consequences of this underappreciated aspect of climate change. We consider a broad range of terrestrial ecosystems that vary in their overall water balance. More extreme rainfall regimes are expected to increase the duration and severity of soil water stress in mesic ecosystems as intervals between rainfall events increase. In contrast, xeric ecosystems may exhibit …

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?

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 …

Water In Beaver Dam Wash And Lytle Preserve, Stanley L. Welsh

Books by Faculty of the Monte L. Bean Life Science Museum

This short work is derived from a manuscript prepared for presentation in a water adjudication hearing, following a proposal to pipe water from wells in Beaver Dam Wash for transfer across state lines to be used for culinary and other purposes in Mesquite, Nevada. The Wash is estimated to yield 2000 acre feet of water annually, mostly as subsurface flow, at the Arizona line. About a third of that amount is already appropriated by users along the Wash in Utah, but there are applications pending for more than 100,000 acre feet in Utah. Thus, the Wash is already oversubscribed by …

Morphology, Reproduction And Mortality Of Equus Hemionus Hemionus In Mongolia, Annegret Stubbe, Michael Stubbe, Nyamsuren Batsaikhan

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

There are collected materials on morphology, reproduction rate, and mortality of Dschiggetajs Equus h. hemionus between 2001 and 2006 in the South Gobi of Mongolia. It were found 794 skeletons of wild asses, 95% of these were pouched, ⅔ of them in winter coat. Pouching was also located in the protected areas of this region. The main living resources of Equus hemionus are registered in the South eastern Gobi. For the first time statistical data on morphology measurements of body length, tail and tuft, ear length, and hoofs are given. There are no significant differences between the sexes. The reproduction …