Desert Ecology Commons^™

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m³. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m³. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982. A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …

Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

Publications (WR)

The purpose of the Las Vegas Wash Advanced Water Quality Study is to determine the existence, extent, and mechanisms of nutrient and toxin stripping in Las Vegas Wash under present conditions and under future conditions, both with and without construction of the proposed salinity control unit as described by the Bureau of Reclamation (USBR, 1982b). This study was performed for the Lower Colorado Region Division of Planning by personnel of the Environmental Sciences Section of the Division of Research and Laboratory Services, E&R Center, Denver, Colorado. Work on the study began in February 1983. The general approach adopted for this …

Water Quality Trends In The Las Vegas Wash Wetlands, F. A. Morris, L. J. Paulson

Publications (WR)

The Las Vegas Wash is a wetlands ecosystem that acts to buffer the effects of wastewater discharges on the receiving waters of Lake Mead. The wash is the terminus for the 4,144 km2 Las Vegas Valley drainage basin, emptying into Las Vegas Bay of Lake Mead (Colorado River). It is in the northern Mojave desert, which receives an average of only 10 cm of rainfall annually. The Las Vegas Wash is technically an artificial wetland supported almost entirely by the perennial flows from sewage treatment plants. These flows contribute an average of 3-7 t of nutrients (nitrogen and phosphorus) and …

An Ecological Analysis Of Relic Diatoms In Sediments Of Las Vegas Bay, Lake Mead, David Ross Hetzel

Publications (WR)

Relic diatoms in sediments of the inner Las Vegas Bay, near the Las Vegas Wash sewage inflow, were examined in order to assess historic trophic conditions in this area of Lake Mead. Diatom sedimentation rates and ratios of Araphidineae/Centrales (A/C) diatom groups were determined from sediment cores collected in the old wash channel 1.5 km from the sewage inflow (station 2), in a small cove 1.5 km further downstream (station 3) and in an adjacent embayment off Gypsum Wash (station 4). Diatom sedimentation rates generally increased from the bottom to the top of each core, but pronounced minima existed at …

Mice Of The Genus Peromyscus In Guadalupe Mountains National Park, Texas, John E. Cornely, David J. Schmidly, Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Mice of the genus Peromyscus are found in virtually every habitat type in Guadalupe Mountains National Park in West Texas. Because of their abundance and wide distribution, they comprise an important component of the park's ecosystem. The first known specimens of Peromyscus from the area now included in the park were collected by Vernon Bailey in 1901 (Bailey, 1905). He collected specimens of Peromyscus boyIii in Dog and McKittrick canyons. Davis (1940) collected P. leucopus at Frijole in 1938 and P. boylii in The Bowl in 1938 and 1939. Davis and Robertson (1944) reported collecting P. pectoralis from along Bell …

Diagenesis Of Organic Matter In Las Vegas Bay And Bonelli Bay, Lake Mead, James W. Murray, Carolyn J. Jones, Kathy Kuivila, Jeff Sawlan

Publications (WR)

The interstitial water chemistry of the sediments of Las Vegas Bay and Bonelli Bay in Lake Mead has been studied as part of a comprehensive water quality study of those locations. Pore water and solid phase analyses were completed from four stations in Las Vegas Bay and two stations in Bonelli Bay. At both locations the pore water compositions and organic matter diagenesis in the sediments are dominated by sulfate reduction. This major role of sulfate reduction is unusual for lake sediments and reflects the fact that SO₄ is the major anion in the lake water. In addition, gypsum …

Die Erforschung Der Herpetofauna Der Mongolischen Volksrepublik: Situation Und Perspektiven, Günther Peters

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

First paragraph:

Die Landschaften der Mongolei sind arm an Reptilien- und Amphibienarten. Dieser Umstand mag die Frage aufwerfen, ob herpetologische Untersuchungen in Beschränkung auf das Territorium der MVR eine nennenswerte Perspektive haben könnten, nachdem Artenspektrum und Verbteitung der Species annähernd vollständig erkundet sind. Ein Herpetologe wird zweifellos für seine Arbeit auch in diesem Land eine Zukunft sehen, doch muß wohl von vornherein eingestanden werden, daß das Volumen der Probleme dieses Faches hinter denen der übrigen Disziplinen der Vertebratenzoologie und der Entomologie in einem bescheidenerem Rahmen verbleibt. Dies gilt sowohl im rein wissenschaftlichen als erst recht auch im angewandten Bereich ihrer …

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …

Environmental Factors Affecting The Diversity Of Reptiles In The Deep Canyon Transect Of The Colorado Desert, California, James W Cornett

Theses Digitization Project

No abstract provided.

A Guide To The Threatened And Endangered Vascular Plants Of The Lake Mead National Recreation Area, James S. Holland, Wesley E. Niles, Charles L. Douglas, Dennis R. Schramm

Publications (WR)

This illustrated guide was prepared to provide the botanical community, land managers, and other interested persons with a reference that describes and locates the twelve plant taxa currently being considered by the Fish and Wildlife Service for threatened or endangered status in or around the Lake Mead National Recreation Area. The guide is intended to assist managers of government agencies in determining the presence of these species and in defining management programs for their protection. The guide should be consulted prior to any construction project. If a potential conflict is identified, an onsite evaluation should be conducted early in the …

Plant Response Parameters To General Patton's Armored Maneuvers In The Eastern Mojave Desert Of California, Randall J. Iwasiuk

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study, which was undertaken from September, 1977 through June, 1978 was to survey the response of perennial vegetation to General Patton's World War II armored maneuvers. This information will be used to help construct a basis for predicting recovery rates on the effects of off-road vehicle impacts in the California Desert Conservation Area (CDCA). These impacts were assessed in three usage categories: tank tracks in the maneuvers areas; roadways, which were used primarily by jeeps and trucks; and tent areas, cleared areas in which tents and other semi-permanent structures were erected. The data generated from these …

Characterization And Identification Of An Isolate Of Halobacterium From Soda Springs Mojave Desert, Abayomi Odubela

Theses Digitization Project

No abstract provided.

A Floristic And Vegetational Analysis In The Lytle Creek Drainage Area Of The San Gabriel Mountains, California, Roy W. Martin

Theses Digitization Project

No abstract provided.

The Effects Of Selected Pre-Germination Treatments On Six Species Of Summer And Winter Annual Plants Of The East Mojave Desert, James R. Earsom

Theses Digitization Project

No abstract provided.

Review Of The Desert Pocket Gopher, Geomys Arenarius (Mammalia: Rodentia), Stephen L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

The desert pocket gopher (Geomys arenarius), which occupies a restricted geographic range in Texas, New Mexico, and Chihuahua, was examined for morphological variation. Univariate and multivariate analyses were used to determine age, sexual, individual, and geographic variation. Significant differences were found among different age classes and between sexes. Males displayed higher individual variation than females and external measurements were more variable than cranial measurements. Two subspecies--G. a. arenarius and G. a. brevirostris--were recognized after analyses of geographic variation.

Comparison Of Microbial Activity In Desert Soils Of The Western United States, Patricia Ann Trujillo Y Fulgham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soils from four regional deserts, Great Basin, Sonoran, Chihuahuan, and Mojave, were collected at times throughout the year which would best exhibit microbial response to moisture or vegetation. The soils were analyzed for several chemical and physical properties. Biological and biochemical characteristics, namely respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, nitrification potential, and microbial numbers, were measured.

The soils exhibited fluctuations in microbial activity as measured by respiration, dehydrogenase activity, adenosine triphosphate concentration, proteolytic activity, and nitrification potential during different moisture seasons.

Increase in soil moisture as modified by precipitation did not cause a significant difference in respiration or …

Limnological Aspects Of Lake Mead, Nevada-Arizona, John R. Baker, James E. Deacon, Thomas A. Burke, Samuel S. Egdorf, Larry J. Paulson, Richard W. Tew, Bureau Of Reclamation

Publications (WR)

Lake Mead is a deep, subtropical, moderately productive, desert impoundment with a negative heterograde oxygen profile occurring during; the summer stratification. investigations of the Boulder Basin of Lake Mead by the University of Nevada were initiated in November 1971. The primary objective of the study was to determine what effects industrial and sewage effluent from the Las Vegas metropolitan area, discharged into Las Vegas Bay, have had on the water quality and limnological conditions of Boulder Basin. Data from the 1975-76 period are presented in detail, with earlier data included in the summaries and discussions. Measurements of water temperature, dissolved …

Biosystematics Of The Abronia Villosa Complex From Southern California, Ned R. Curtis

Theses Digitization Project

No abstract provided.

A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman

Publications (WR)

1. The waters of Las Vegas Bay, a heavily utilized recreational resource, receive discharges from a variety of municipal and industrial waste sources. The U.S. Environmental Protection Agency has determined, on the basis of numerous studies, that the present water quality violates state and federal standards and constitutes a public nuisance. Consultants have advised the Sewage and Wastewater Advisory Committee that rapid abatement of the alleged pollution conditions can be achieved by an advanced wastewater treatment (AWT) plant.

2. The major problems in Las Vegas Bay are an objectionable water color, excessive turbidity, noxious odors, and oxygen depletion in certain …

Annotated Checklist Of The Vascular Plants Of Washington County, Utah, Susan Elizabeth Meyer

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis is comprised of two parts, the annotated checklist of plants and the explanatory text which precedes it.

The checklist includes entries for the 1,207 vascular plant species known to occur in Washington county. each entry consists of species name, floristic component classification, community type occurrence, range termination information, specimen citations, and in some cases notes and relevant synonymy.

The explanatory text includes a discussion of the methods used in the preparation of the checklist, a description of the study area, a conspectus of botanical research in the area, and a summary of the systematic and phytogeographic affiliations of …

Distribution Of Stream Pollution In Lake Water, Richard W. Tew, Samuel S. Egdorf, James E. Deacon

Publications (WR)

Wastewater effluent-laden waters from Las Vegas Wash (LVW) form a density current that may be detected in Boulder Basin of Lake Mead at considerable distances from the wash estuary. This led to the suspicion that water from the inflowing stream [40 mgd (1.5 X 10⁵ cu m/day)] might not be rapidly diluted in the enormous volume of the lake [19 mil acre-ft (2.3 X 10¹⁰ cu m)], but might persist as a recognizable entity to the vicinity of the intake of a major water source for populous Clark County, Nev.

Because of the detection sensitivity implicit in the …

Emus On The Move : 1976, Michael T. Sexton

Journal of the Department of Agriculture, Western Australia, Series 4

The greatest migration of emus in recent times came out of the ZMurchison and Gascoyne pastoral areas during the winter of 1976. The emus were driven south-westerly by an instinctive search for food.

The Agriculture Protection Board's barrier fences stoped the wave of emus on the fringes of the wheatbelt, causing a congregation estimated in mid June to total 50,000 birds.

This article reviews the reason behind the emu migration and the policies employed to deal with such a situation.

Biological Inventory Of The Southern Nevada Water Project, Second Stage, W. Glen Bradley, J. Scott Miller

Publications (WR)

The present report is a biological inventory of the Southern Nevada Water Project, Second Stage. The boundaries of the project encompass sections of North Las Vegas, Las Vegas, East Las Vegas and areas along Las Vegas Wash extending to its drainage point in Las Vegas Bay in Lake Mead. Therefore, it encompasses a wide array of ecological situations and landscapes ranging from essentially natural to various stages of urban development.

This biological inventory presents basic ecological classifications, descriptions of vegetation, lists of vascular plants and vertebrates known to occur in the area. Each major group, i.e., plants, fish, amphibians, reptiles, …

Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki

Publications (WR)

The ¹⁴C light and dark bottle technique for measurement of primary production was utilized as a means of assessing the amount of inorganic carbon being converted Into organic form by the photosynthesis of phytoplankton populations In the Boulder Basin of Lake Mead.

Spatial and time series changes of productivity levels observed at eight sampling locations within Boulder Basin Indicate that the Influence of treated municipal arts' industrial effluent flowing into Les Vegas Bay is contributing high levels of available nutrients at Las Vegas Wash Inlet to cause productivity to approximate those levels associated with polluted waters.

Productivity levels at …

Editors' Note To Biological Investigations In The Guadalupe Mountains National Park, Texas., Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

The Guadalupe Mountains National Park, which is located in TransPecos Texas between Carlsbad, New Mexico, and EI Paso, Texas, is one of the newest national parks being formed by the Congress in 1967. The Guadalupe Mountains and the associated Chihuahuan Desert included in the park represent a unique biological area in which a fragile biological equilibrium exists between the fauna and flora of the Chihuahuan Desert of the lowlands and the Rocky Mountains of the high elevations. The preservation of this area will depend upon sound management decisions. This volume is the result of a symposium held at The Museum …

Biological Inventory In Conjunction With The Las Vegas Wash Unit, Colorado River Basin Salinity Control Act Title Ii (P.L. 93-320), W. Glen Bradley, J. Scott Miller

Publications (WR)

The present report is a biological inventory in conjunction with the Las Vegas Wash Unit, Colorado River Basin Salinity Control Act, Title II. The boundaries of the project encompass sections of North Las Vegas, Las Vegas, East Las Vegas and areas along Las Vegas Wash extending to its drainage point in Las Vegas Bay in Lake Mead. Therefore, it encompasses a wide array of ecological situations and landscapes ranging from essentially natural to various stages of urban development. This biological inventory presents basic ecological classifications, descriptions of vegetation, lists of vascular plants and vertebrates known to occur in the area. …

Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew

Publications (WR)

This program was a status study of the interaction between Las Vegas Wash, an enriched stream, and Las Vegas Bay, a wedge shaped arm of one of the world's deeper reservoirs. The program centered primarily on identification and counting of planktonic algae from several points in Las Vegas Bay. Additional work on nutrient enrichment of water samples was conducted to aid in interpretation of algal distribution related to nutrient input. Examination of a variety of physical, chemical, and biological parameters, both at many surface points in the bay, as well as in vertical profile, was also accomplished and further aided …

Phytoplankton Successions And Lake Dynamics In Las Vegas Bay, Lake Mead, Nevada, Ervon R. Koening, Richard W. Tew, James E. Deacon

Publications (WR)

Phytoplankton successions, applications of the general growth equation, and physical measurements have been employed to investigate events occurring at the interface between industrial and sewage effluent contained in Las Vegas Wash and the waters of Lake Mead, Nevada. The data indicate that the entering waters tend to form a density current interrupted at intervals by dynamic effects generated in the lake. The dynamic relationships described here for the spring months suggest that a much more thorough understanding of physical, chemical and biological interactions is necessary to permit solution of the numerous problems of Las Vegas Bay discussed or alluded to …

Report On Water Pollution Problems In Las Vegas Wash And Las Vegas Bay, Environmental Protection Agency

Publications (WR)

This report was prepared by the Federal Water- Quality Administration, Pacific Southwest Region, now the Environmental Protection Agency (EPA), Region IX, at the request of the State of Nevada, Department of Health, Welfare, and rehabilitation. In a letter, dated December 5, 1969, this agency asked for technical assistance, as authorized by the Federal Water Pollution Control Act, in developing discharge standards appropriate for Las Vegas Bay, Lake Mead, and the Lower Colorado River. The subsequent study was performed by EPA from January through August, 1970. The establishment of Nevada State Water Quality Standards for these waters will enable responsible officials …