Digital Commons Network^™

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 …

Microbial Community Function In Freshwater Wetland Soils: Using Extracellular Enzyme Analysis To Study The Effect Of Moisture And Vegetation, Aaron Porter

Theses and Dissertations

Differences in microbial function via extracellular enzyme activity (EEA) were investigated to determine the potential effects of hydrology and plant-soil-microbe interactions in a young non-tidal freshwater riparian wetland. To study these relationships, three plots were established along a moisture gradient (Wet, Intermediate, Dry) within VCU Rice Center Within each main plot, five subplots were left undisturbed while another five were cleared of all above-ground plant biomass. Homogenized soil cores (top 10 cm) were analyzed for pH, redox, C:N, soil organic matter (SOM) content, saturation, and temperature. Microbial function was assessed using extracellular enzyme analysis. For most enzymes, a site difference …

Phragmites Australis In South Dakota: Historical Distribution And Environment, Carol A. Johnston, Kayla L. Miller

The Prairie Naturalist

Common reed, Phragmites australis, has long been a component of Northern Plains wetlands, but impending invasion by the non-native P. australis haplotype M may displace native haplotypes in the future. To increase understanding of historical Phragmites occurrence, we developed a geographic information system (GIS) protocol to improve the georeferencing of specimens from South Dakota herbaria, and mapped the distribution of Phragmites relative to geology, physiographic regions, and water bodies. There were 91 Phragmites herbarium specimens from South Dakota and adjacent Wyoming. Phragmites collections occurred in nearly all physiographic regions of the state, with concentrations occurring in the Prairie Coteau of …

Habitat Selection By Female Swift Foxes (Vulpes Velox) During The Pup- Rearing Season, Indrani Sasmal, Jonathan A. Jenks, Troy W. Grovenburg, Shubham Datta, Greg. M. Schroeder, Robert W. Klaver, Kevin M. Honness

The Prairie Naturalist

The swift fox (Vulpes velox) was historically distributed in western South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1800s, largely due to habitat loss and poisoning targeted at wolves (Canis lupis) and coyotes (C. latrans). Only a small population of swift foxes near Ardmore, South Dakota persisted. In 2003, an introduction program was initiated at BNP with swift foxes translocated from Colorado and Wyoming. We report on habitat use by female swift foxes during the pup-rearing season (May–July) in 2009. Analyses of location data from 13 radiomarked female foxes indicated disproportional use (P < 0.001) of some habitats relative to their availability within swift fox home ranges. Swift foxes used grassland (ŵ = 1.01), sparse vegetation (ŵ = 1.43) and prairie dog towns (ŵ = 1.18) in proportion to their availability, whereas they were less likely to use woodland (ŵ = 0.00), shrubland (ŵ = 0.14), pasture/agricultural-land (ŵ = 0.25) and development (ŵ = 0.16) relative to availability. Swift foxes typically are located in habitats that provide greater visibility, such as shortgrass prairie and areas with sparse vegetation; which allow detection of approaching coyotes (e.g., primary predator of swift foxes).

Distribution Of Crayfish Species In Select North Dakota Streams, Cari-Ann Hayer, Terrance L. Velazquez, Mclain S. Johnson, Brian Graeb

The Prairie Naturalist

Crayfish have an integral role in aquatic ecosystems, serving as herbivores, predators, detritivores, and prey for fishes and other aquatic and terrestrial animals (Momot 1995, Taylor et al. 1996, Martin 1997). Many crayfish populations are currently declining as a result of habitat alteration (Taylor et al. 1996) and invasive predators (e.g., rusty crayfish Orconectes rusticus [Girard; Lodge et al. 2000]). Knowledge of crayfish distribution and biology in North America and specifically North Dakota is sparse or lacking (Taylor et al. 1996) and baseline information is necessary to identify effects of anthropogenic alterations. Early inventories documented 3 crayfish species in North …

Developing Digital Field Guides For Plants: A Study From The Perspective Of Users, Emily Roseanne Schwarz

Master's Theses

A field guide is a tool to identify an object of natural history. Field guides
cover a wide range of topics from plants to fungi, birds to mammals, and shells to minerals. Traditionally, field guides are books, usually small enough to be carried outdoors . They enjoy wide popularity in modern life; almost every American home and library owns at least one field guide, and the same is also true for other areas of the world.

At this time, companies, non-profits, and universities are developing computer
technologies to replace printed field guides for identifying plants. This thesis
examines the state …

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 …

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. …

Population Structure Based On Age-Class Distribution Of Tapirus Polkensis From The Gray Fossil Site Tennessee., Matthew L. Gibson

Electronic Theses and Dissertations

Individuals of Tapirus polkensis from the Gray Fossil Site exhibit an excellent level of preservation. Intact skulls collected from the site were arranged in a rough age class system separated into 7 categories based on the teeth present and amount of dental wear. Such an eruption series is useful for general comparisons amongst the individual tapirs; however, the classes do not represent an age in years due to a lack of data on living tapirs. Consequently, it is possible that some age classes may contain several years of a tapirs life, or comparatively only a few months. In this study …

The Effect Of Stream Restoration On Preferred Cutthroat Trout Habitat In The Strawberry River, Utah, Nicolas R. Braithwaite

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stream restoration has become a popular management tool for attempting to increase and/or restore fish populations by improving habitat. A section of the Strawberry River, Utah recently underwent a stream restoration project, where the main goals of the project included increasing spawning activity, rearing potential, and resident populations of Bear Lake cutthroat trout Oncorhynchus clarkia utah. The impact of the restoration project on cutthroat trout was investigated by first characterizing preferred habitat for different life stages, investigating habitat as a limiting factor in the system, and then assessing the quality of available habitat by comparing restored/unrestored sections of stream …

A Longitudinal Study On Anopheles Mosquito Larval Abundance In Distinct Geographical And Environmental Settings In Western Kenya, Susan S. Imbahale, Krijn P. Paaijmans, Wolfgang R. Mukabana, Ron Van Lammeren, Andrew K. Githeko, Willem Takken

All Peer-Reviewed Publications

Background: As the ecology of mosquito larvae can be complex there is need to develop a rational framework for undertaking larval ecological studies. Local environmental characteristics, such as altitude, climate and land use, can significantly impact on phenology and population dynamics of mosquito larvae, and indirectly affect the dynamics of mosquito-borne diseases. The aim of this study was to assess the feasibility of implementing an integrated approach to larval source management under the distinct ecological settings. Methods. The study was conducted in two highland villages and one village, at a lower altitude, in the Lake Victoria basin, where malaria is …

Macroinvertebrate Community Analysis On Lower Hood River Before And During The Removal Of Powerdale Dam: A Baseline Study, Howard Jay Patterson

Environmental Science and Management Professional Master's Project Reports

Powerdale Dam was an 87-year-old hydroelectric complex on lower Hood River in northern Oregon which was decommissioned in 2010. Macroinvertebrate samples were collected in 2009, before the removal process began, and in 2010, near the end of the demolition project, at one site upstream and three sites downstream of the dam. Macroinvertebrate communities were analyzed using both multi-metric (Benthic Index of Biotic Integrity [B-IBI]) and multivariate (Predictive Assessment Tool for Oregon [PREDATOR]) approaches, as well as EPT and Functional Feeding Group (FFG) analysis. All analytical approaches indicated declines in habitat quality in 2010 relative to 2009, and showed increasing impairment …

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 …

River Geomorphology And Fish Barriers Affect On Spatial And Temporal Patterns Of Fish Assemblages In The Niobrara River, Nebraska, Greg A. Wanner, Mark A. Pegg, Steven Schainost, Robert A. Klumb, Dane A. Shuman

School of Natural Resources: Faculty Publications

The Niobrara River in northern Nebraska traverses the heart of the Great Plains with portions of the river protected under the National Wild and Scenic River system managed by the National Park Service. The Niobrara River changes from a narrow, entrenched stream to a wide, highly braided river with four fish barriers and 36 distinct geomorphic segments in the lower 531 river kilometers (rkm). Our objectives were to examine the spatial and temporal patterns of fish assemblages in the Niobrara River related to environmental variables, fish barriers, and river geomorphology. Tote-barge electrofishing occurred monthly from June to September in 2009 …

Modeling Moisture Fluxes Using Artificial Neural Networks: Can Information Extraction Overcome Data Loss?, A. L. Neal, H. V. Gupta, S. A. Kurc, P. D. Brooks

Environmental Science and Geology Faculty Research Publications

Eddy covariance sites can experience data losses as high as 30 to 45% on an annual basis. Artificial neural networks (ANNs) have been identified as powerful tools for gap filling, but their performance depends on the representativeness of data used to train the model. In this paper, we develop a normalization method, which has similar performance compared to conventional training approaches, but exhibits differences in the timing of fluxes, indicating different and previously unused information in the data record. Specifically, the differences between half-hourly model fluxes, especially during summer months, indicate that the structure of the information content in the …

Review Of Mammalian Teeth: Origin, Evolution, And Diversity By Peter S. Ungar, Patricia W. Freeman

School of Natural Resources: Faculty Publications

Peter Ungar has written a book on mammalian teeth, a topic close to the heart of mammalogy itself and most mammalogists. His distillation of the massive literature on teeth into a succinct whole will appeal to scientists and professionals across disciplines. With paleontological and extant dental research in one place I no longer have to search these areas separately to find what I want. Ungar’s broad background includes physical anthropology, anatomy, and paleontology. Further, he has been one of the pioneers using dental microwear to analyze diets in primates and geographic information systems (GISs) on a microscale to study cusps …

Profiles In Science For Science Librarians: "What Lives Where, And Why": Alfred Russel Wallace, And The Field Of Biogeography, Charles H. Smith

DLPS Faculty Publications

Biogeography, the study of animal and plant distribution, has a history extending back to at least the eighteenth century. But it was not until the work of Charles Darwin and Alfred Russel Wallace in the mid-nineteenth century that it really came into its own as a science. Darwin’s importance notwithstanding, it was really Wallace who put the field on the map, and many of today’s research threads can be traced back to his influence. This article provides a summary review of Wallace’s life and work and biogeography as a field of study, including Wallace’s role in its development.

On The Brink Of Change: Plant Responses To Climate On The Colorado Plateau, Seth M. Munson, Jayne Belnap, M. Schelz, Mary Moran, T. W. Caolin

Canyonlands Research Bibliography

The intensification of aridity due to anthropogenic climate change in the southwestern U.S. is likely to have a large impact on the growth and survival of plant species that may already be vulnerable to water stress. To make accurate predictions of plant responses to climate change, it is essential to determine the long-term dynamics of plant species associated with past climate conditions. Here we show how the plant species and functional types across a wide range of environmental conditions in Colorado Plateau national parks have changed with climate variability over the last twenty years. During this time, regional mean annual …

The Response Of Fish Larvae To Decadal Changes In Environmental Forcing Factors Off The Oregon Coast, Toby D. Auth, Richard D. Brodeur, Heather L. Soulen, Lorenzo Ciannelli, William T. Peterson

United States Department of Commerce: Staff Publications

We conducted a statistical analysis to characterize the influence of large-scale and local environmental factors on presence-absence, concentration, and assemblage structure of larval fish within the northern California Current (NCC) ecosystem, based on samples collected at two nearshore stations along the Newport Hydrographic line off the central Oregon coast. Data from 1996 to 2005 were compared with historical data from the 1970s and 1980s to evaluate pseudo-decadal, annual, and seasonal variability. Our results indicate that the most abundant taxa from 1996 to 2005 differ from those of earlier decades. Concentrations of the dominant taxa and total larvae were generally greater …

Migration And Behavior Of Juvenile North Pacific Albacore (Thunnus Alalunga), John Childers, Stephanie Snyder, Suzanne Kohin

United States Department of Commerce: Staff Publications

Archival tags were used to study the seasonal movements, migration patterns and vertical distribution of juvenile North Pacific albacore (Thunnus alalunga). Between 2001 and 2006, archival tags were deployed in North Pacific albacore in two regions of the Northeast Pacific: (i) off Northern Baja California, Mexico and Southern California, and (ii) off Washington and Oregon. Twenty archival tagged fish were recovered with times at liberty ranging from 63 to 697 days. Tagged albacore exhibited five distinct, seasonal migratory patterns. Depth and temperature data also showed a broad range of vertical behaviors. In certain regions such as off Baja …

Life History Of The Indo-Pacific Humpback Dolphin In The Pearl River Estuary, Southern China, Thomas A. Jefferson, Samuel K. Hung, Kelly M. Robertson, Frederick I. Archer

United States Department of Commerce: Staff Publications

We studied life history characteristics of the Hong Kong/Pearl River Estuary population of Indo-Pacific humpback dolphins (Sousa chinensis), based on data from 120 specimens stranded between 1995 and 2009, 40 individuals biopsied at sea, and a long-term (14+ yr) photo-identification study. Ages were determined for 112 specimens by thin-sectioning teeth and counting growth layer groups. Estimated length at birth was 101 cm. Longevity was at least 38 yr, and there was little difference in growth patterns of males and females. Growth was described by a Bayesian two-phase Gompertz model; asymptotic length was reached at 249 cm. The tooth …

Ontogenetic Dietary Information Of The California Sea Lion (Zalophus Californianus) Assessed Using Stable Isotope Analysis, Anthony J. Orr, Seth D. Newsome, Jeffrey L. Laake, Glenn R. Vanblaricom, Robert L. Delong

United States Department of Commerce: Staff Publications

We used stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes to examine ontogenetic dietary changes in 289 California sea lions (Zalophus californianus) at San Miguel Island, California during 2004–2007. Tissues analyzed included fur, red blood cells, plasma, and serum. For all tissues, pups had higher δ¹⁵N values and lower δ¹³C values compared to adults, which indicated that pups were feeding higher trophically than older conspecifics and on a lipid-rich milk diet prior to weaning. Yearling δ¹⁵N values were slightly lower than pup or nearly indistinguishable from adult values depending …

Fire Ecology And Management Of Non-Forested Ecosystems In Western North America. Final Report: Description Of Organizational Meetings And Development Of A Publication Plan, Matt Brooks

Joint Fire Science Program Research Project Reports

It has been almost 30 years since the last major book on the ecology and management of fire was published that contained extensive information from non-forested ecosystems across western North America (Wright and Bailey 1982). During subsequent years there have been notable books that have focused largely on forested ecosystems (e.g. Agee 1993), and there was one very recent book that addressed many important grassland, shrubland, woodland, and forest areas, but its geographic extent was confined to California (Sugihara et al. 2006). No single book has since matched the geographic scope associated with non-forested ecosystems in western North America as …

Fire Regimes Of Montane Grasslands Of The Valles Caldera National Preserve, New Mexico, Donald A. Falk, Craig D. Allen, Robert Parmenter, Thomas Swetnam, Clifford Dils

Joint Fire Science Program Research Project Reports

Montane grasslands are an important ecosystem type in Southwestern landscapes, occurring from the forest borders of piñon-juniper woodland to high elevation subalpine and alpine ecosystems. Thus, they often represent a mosaic element embedded in the forest landscape matrix, playing key roles in processing water and nutrients, and providing habitat for unique suites of species, often at higher levels of diversity than those found in surrounding uplands. Soils, local temperature and moisture gradients, and disturbance all play roles in determining the distribution and extent of montane grasslands. Of these factors, fire plays the most dynamic role in regulating the location and …

Multimodel Inference And Adaptive Management, Sarah E. Rehme, Larkin A. Powell, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Ecology is an inherently complex science coping with correlated variables, nonlinear interactions and multiple scales of pattern and process, making it difficult for experiments to result in clear, strong inference. Natural resource managers, policy makers, and stakeholders rely on science to provide timely and accurate management recommendations. However, the time necessary to untangle the complexities of interactions within ecosystems is often far greater than the time available to make management decisions. One method of coping with this problem is multimodel inference. Multimodel inference assesses uncertainty by calculating likelihoods among multiple competing hypotheses, but multimodel inference results are often equivocal. Despite …

Population Viability Analysis Of Swift Fox (Vulpes Velox) At The Badlands National Park, Indrani Sasmal

Electronic Theses and Dissertations

The swift fox (Vulpes velox) was historically distributed in southwestern South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1900s due to habitat fragmentation, non-target poisoning, and harvest. A remnant population occurred on USDA Forest Service lands in Fall River County, South Dakota. Following the successful reintroduction of the species in Canada (1983), a reintroduction program was initiated in BNP in the year 2003. Free-ranging swift fox from Colorado and Wyoming were translocated to BNP from 2003 to 2006. Despite these releases and observations of free-ranging swift fox occurring throughout western South Dakota, it …

Mapping Biomass And Stress In The Sierra Nevada Using Lidar And Hyperspectral Data Fusion, Anu Swatantran, Ralph Dubayah, Dar A. Roberts, Michelle Hofton, J. Bryan Blair

United States National Aeronautics and Space Administration: Publications

In this paper, we explored fusion of structural metrics from the Laser Vegetation Imaging Sensor (LVIS) and spectral characteristics from the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) for biomass estimation in the Sierra Nevada. In addition, we combined the two sensors to map species-specific biomass and stress at landscape scale. Multiple endmember spectral mixture analysis (MESMA) was used to classify vegetation from AVIRIS images and obtain sub-pixel fractions of green vegetation, non-photosynthetic vegetation, soil, and shade. LVIS metrics, AVIRIS spectral indices, and MESMA fractions were compared with field measures of biomass using linear and stepwise regressions at stand (1 ha) …

Quantitative Approaches In Climate Change Ecology, Christopher J. Brown, David S. Schoeman, William J. Sydeman, Keith Brander, Lauren B. Buckley, Michael Burrows, Carlos M. Duarte, Pippa J. Moore, John M. Pandolfi, Elvira Poloczanska, William Venables, Anthony J. Richardson

Research outputs 2011

Contemporary impacts of anthropogenic climate change on ecosystems are increasingly being recognized. Documenting the extent of these impacts requires quantitative tools for analyses of ecological observations to distinguish climate impacts in noisy data and to understand interactions between climate variability and other drivers of change. To assist the development of reliable statistical approaches, we review the marine climate change literature and provide suggestions for quantitative approaches in climate change ecology. We compiled 267 peer-reviewed articles that examined relationships between climate change and marine ecological variables. Of the articles with time series data (n = 186), 75% used statistics to test …

Determinants Of Local And Migratory Movements Of Great Lakes Double-Crested Cormorants, Alban Guillaumet, Brian S, Dorr, Guiming Wang, Jimmy D. Taylor Ii, Richard B. Chipman, Heidi Scherr, Jeff Bowman, Kenneth F. Abraham, Terry J. Doyle, Elizabeth Cranker

United States Department of Agriculture Wildlife Services: Staff Publications

We investigated how individual strategies combine with demographic and ecological factors to determine local and migratory movements in the double-crested cormorants (Phalacrocorax auritus). One hundred and forty-five cormorants were captured from 14 nesting colonies across the Great Lakes area and fitted with satellite transmitters. We first tested the hypotheses that sexual segregation, density-dependent effects, and the intensity of management operations influenced home range size during the breeding season. The influence of these factors appeared to be limited in part due to random variability in foraging and dispersal decisions at individual and colony levels. We also designed a statistical …

Introduction To “Environmental Contaminants In Biota, 2nd Edition”, W. Nelson Beyer, James P. Meador

United States Geological Survey: Staff Publications

Ecotoxicology is the study of the movement of environmental contaminants through ecosystems and their effects on plants and animals. Examining tissue residues of these contaminants in biota is basic to ecotoxicology, both for understanding the movement of contaminants within organisms and through food chains, and for understanding and quantifying injuries to organisms and their communities. This book provides guidance on interpreting tissue concentrations of environmental contaminants.

Tissue concentrations have long been used both to identify the cause of toxicity in animals and as a measure of the severity of toxicity. More recently, they have been incorporated into environmental models, tying …