Digital Commons Network^™

The Mexican Spotted Owl Controversy: An Example Of The Esa’S Dominant Role In Federal Land Use Planning, Norman D. James

The Past, Present, and Future of Our Public Lands: Celebrating the 40th Anniversary of the Public Land Law Review Commission’s Report, One Third of the Nation’s Land (Martz Summer Conference, June 2-4)

19 pages, including illustrations and a map.

Includes footnotes.

Includes a 7 page publication by the U.S. Dept. of Agriculture, Forest Service, Southwest Region, titled: Changing Conditions in Southwestern Forests and Implications on Land Stewardship.

Changing Patterns Of Microhabitat Utilization By The Threespot Damselfish, Stegastes Planifrons, On Caribbean Reefs, William F. Precht, Richard B. Aronson, Ryan M. Moody, Les M. Kaufman

Ocean Engineering and Marine Sciences Faculty Publications

The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating interactions among corals, algae, and herbivores on Caribbean coral reefs. The preferred microhabitat of S. planifrons is thickets of the branching staghorn coral Acropora cervicornis. Within the past few decades, mass mortality of A. cervicornis from white-band disease and other factors has rendered this coral a minor ecological component throughout most of its range. Methodology/Principal Findings:Survey data from Jamaica (heavily fished), Florida and the Bahamas (moderately fished), the Cayman Islands (lightly to moderately fished), and Belize (lightly fished) indicate that distributional patterns of S. planifrons are positively correlated with live …

Long-Term Spatial And Temporal Variability Of Benthic Macroinvertebrate Communities: Implications For Bioassessment Of Lotic Systems, Eve O'Connor

Theses and Dissertations

The structure and composition of benthic macroinvertebrate communities can vary spatially and over time. Spatial and temporal variation along a stream has many implications for population and community dynamics, which may influence bioassessment programs. I examined variability in the benthic community of eight streams within the Polecat Creek, Virginia watershed. These streams vary in size from 1st to 4th order. The streams were sampled once every season for eleven years using standard bioassessment protocols. Macroinvertebrates were sampled from both sediment and submerged wood habitats at each site. The coefficient of variation (CV) was used to quantify among season, among year …

Development Of Representative Species-Level Molecular Markers And Morphological Character Analysis Of Leucothoid Amphipods (Crustacea: Amphipoda), Kristine Nicolle White

Dissertations

Leucothoid amphipods were investigated using morphology and molecular rDNA gene sequence fragments. The morphological diagnostic characters for traditional taxonomy have been clarified, a molecular marker for representative species has been developed, and one of the current anamorph-leucomorph connections has been confirmed with molecular sequence data. Ultimately this study has combined traditional morphological and modern molecular methods to clarify the taxonomy and to propose a preliminary phylogeny of the Leucothoidae. Analysis of 18S rDNA gene fragments from 13 species in two genera supported the current morphological species designations and the separation of the family into two clades. Combined analysis of 18S …

Plastic And Genetic Determination Of Population, Community, And Ecosystem Properties In Freshwater Environments, Leigh C. Latta Iv

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The hierarchy of biological organization, from molecules to ecosystems, describes the relationships among various biological systems. Of particular interest is assessing how the factors that primarily determine the nature of one hierarchical level also have transcendent qualities that affect the ecology and evolution of higher hierarchical levels. The goal of this dissertation was to use a bottom-up approach to examine the transcendent effects of two factors that strongly determine the nature of their associated level of biological organization. The first, phenotypic plasticity, is a primary factor that determines the phenotype of an individual. The second factor, genetic diversity, largely determines …

Terrestrial Ecosystem Classification In The Rocky Mountains, Northern Utah, Antonin Kusbach

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Currently, there is no comprehensive terrestrial ecosystem classification for the central Rocky Mountains of the United States. A comprehensive classification of terrestrial ecosystems in a mountainous study area in northern Utah was developed incorporating direct gradient analysis, spatial hierarchy theory, the zonal concept, and concepts of diagnostic species and fidelity, together with the biogeoclimatic ecosystem classification approach used in British Columbia, Canada.

This classification was derived from vegetation and environmental sampling of both forest and non-forest ecosystems. The SNOwpack TELemetry (SNOTEL) and The National Weather Service (NWS) Cooperative Observer Program (COOP) weather station network were used to approximate climate of …

Climate Change: Implications For Montane Mammals Of The Great Basin, Georgina Yvette Jacquez

Master's Theses or Doctor of Nursing Practice

Climate change threatens biodiversity; in particular, species with narrow distributions and specific habitat requirements. The Great Basin provides an excellent model system to evaluate the effects of climate change on species with isolated distributions and specific habitat requirements. I have evaluated the McDonald and Brown (1992) model that examined the effects of climate change on montane mammals of the Great Basin based on its underlying assumptions and model predictions. I have modeled the distributions of twelve montane mammal species found in the Great Basin and identified potential local extinctions by using maximum entropy modeling (Maxent) for two emission scenarios of …

Annual Rainfall And Seasonality Predict Pan‐Tropical Patterns Of Liana Density And Basal Area, Saara J. Dewalt, Stefan A. Schnitzer, Jérôme Chave, Frans Bongers, Robyn J. Burnham, Zhiquan Cai, George B. Chuyong, David B. Clark, Corneille E.N. Ewango, Jeffrey J. Gerwing, Esteban Gortaire, Terese Hart, Guillermo Ibarra-Manriquez, Kalan Ickes, David Kenfack, Manuel J. Macía, Jean-Remy Makana, Miguel Martinez-Ramos, Joseph Mascaro, Sainge Moses, Helene C. Muller-Laudau, Marc P.E. Parren, Narayanaswamy Parthasarathy, Diego R. Perez-Salicrup, Francis E. Putz, Hugo Romero-Saltos, Duncan W. Thomas

Biological Sciences Faculty Research and Publications

We test the hypotheses proposed by Gentry and Schnitzer that liana density and basal area in tropical forests vary negatively with mean annual precipitation (MAP) and positively with seasonality. Previous studies correlating liana abundance with these climatic variables have produced conflicting results, warranting a new analysis of drivers of liana abundance based on a different dataset. We compiled a pan‐tropical dataset containing 28,953 lianas (≥2.5 cm diam.) from studies conducted at 13 Neotropical and 11 Paleotropical dry to wet lowland tropical forests. The ranges in MAP and dry season length (DSL) (number of months with mean rainfall < 100 mm) represented by these datasets were 860–7250 mm/yr and 0–7 mo, respectively. Pan‐tropically, liana density and basal area decreased significantly with increasing annual rainfall and increased with increasing DSL, supporting the hypotheses of Gentry and Schnitzer. Our results suggest that much of the variation in liana density and basal area in the tropics can be accounted for by the relatively simple metrics of MAP and DSL.

Conservation And Ecology Of The Yellow-Blotched Sawback (Graptemys Flavmaculata), William Winsyl Selman Ii

Dissertations

The role of species conservation is becoming increasingly important due to the mounting pressures from humans on habitats and populations of organisms. This is particularly evident in riverine ecosystems throughout the world where the human demand for freshwater resources is increasing, and consequently, the number of imperiled aquatic organisms is also growing. The seven chapters of this dissertation primarily focus on the Yellow-blotched Sawback, Graptemys flavimaculata, an endangered riverine turtle that is endemic to the Pascagoula River system of southeast Mississippi, USA. At the population level, we aimed to study the impacts of Hurricane Katrina on two study populations within …

Evaluating Native Wheatgrasses For Restoration Of Sagebrush Steppes, Jayanti Ray Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pseudoroegneria spicata and Elymus wawawaiensis are two native perennial bunchgrasses of North America's Intermountain West. Frequent drought, past overgrazing practices, subsequent weed invasions, and increased wildfire frequency have combined to severely degrade natural landscapes in the region, leading to a decline in the abundance of native vegetation. Being formerly widespread throughout the region, P. spicata is a favorite for restoration purposes in the Intermountain West. Elymus wawawaiensis, which occupies a more restricted distribution in the Intermountain West, is often used as a restoration surrogate for P. spicata. However, since most restoration sites are outside the native range of …

The Effect Of In-Line Lakes On Dissolved Organic Matter Dynamics In Mountain Streams, Keli J. Goodman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research combines observation, experimentation, and modeling to evaluate the influence of lakes on dissolved organic matter (DOM) quantity, quality and export in subalpine watersheds of the Sawtooth Mountain Lake District, central Idaho.

First, I conducted an empirical study of the hydrologic and biogeochemical controls on DOM dynamics in stream-lake fluvial networks. I hypothesized that lakes would decrease temporal variability (i.e., buffer) and alter the characteristics of DOM from inflow to outflow. I tested these hypotheses by evaluating DOM temporal patterns and measuring annual export in seven-paired lake inflows and outflows. I then evaluated how ultraviolet (UV) exposure affected DOM …

Greater Sage-Grouse Seasonal Ecology And Responses To Habitat Manipulations In Northern, Utah, Eric T. Thacker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Declining greater sage-grouse populations (Centrocercus urophasianus; hereafter sage-grouse) have led to increased concern regarding the long-term stability of the species. Previous research has identified factors contributing to the observed population declines. Habitat degradation and loss have been implicated as major factors in population declines. Although much is known about sage-grouse biology, more information is needed about population responses to specific management actions. This research was conducted to document sage-grouse responses to site-specific management actions. Additionally, I evaluated sage-grouse temporal and seasonal habitat-use and the comparability of techniques used by range and wildlife managers to measure vegetation responses of …

Tracing Deuterium Through The Food Web And Into Birds And Mammals Along An Elevational Gradient In The Southern Rocky Mountains, Matthew J. Baumann

Biology ETDs

Animals incorporate local δ2H values from available water and dietary sources during tissue synthesis, which can provide evidence of elevational movements if multiple tissues with different turnover times are examined. Here we test the applicability of using δ2H as an indicator of altitudinal movements by examining multiple tissues (δ2Hbw (body water), δ2Hfeather, δ2Hfur, and δ2Hclaw) in birds and mammals in the Sangre de Cristo Mountains. Additionally, we measured δ2Hsw (stem water) and insect δ2bw and δ2wb (whole body) values to assess changes with elevation. We sampled 15 species of birds and two small mammal species along with potential food sources …

Spatial And Temporal Distribution Of Larval Fishes In A Large Tidal River., Harold Seelig

Theses and Dissertations

There are few published studies of larval fish assemblages from unregulated, tidal freshwater rivers. Patterns in the spatial and temporal distribution of larval fishes in the Mattaponi River were examined. Sampling took place on a weekly basis from February through August, 2006 and 2007. Larval fishes were categorized by taxa, reproductive guild, and residency guild. Group comparisons using multi-response permutation procedures (MRPP) indicated significant spatial and temporal differences in assemblage composition on multiple scales. Differences in assemblage composition were analyzed using non-metric multidimensional scaling (NMS). Interannual differences were attributable to anadromous and semi-migratory species. Seasonal differences were attributable to herrings, …

Un Estudio Ecológico De Las Lagartijas Del Valle Seco De Buenavista Y De Los Valles Húmedos De La Josefina Y Salango, Ross Brennan

Independent Study Project (ISP) Collection

La región costera del sur de la provincia de Manabí, Ecuador es un lugar de gran biodiversidad y endemismo. En esta zona el desierto peruano del Tumbes y el bosque húmedo del Chocó se encuentran. La gran cantidad de especies endémicas y la alta biodiversidad resultan de la interacción entre las dos regiones y la diversidad de hábitats que crean. Hay bosques secos tropicales y bosques húmedos muy cerca de Puerto López. Sin embargo, esta región está cambiando rápidamente debido a las actividades humanas; hay progresiva desertificación y otras amenazas a la diversidad. Además, no hay muchos estudios de la …

Investigations Into The Application Of Single-Beam Acoustic Backscatter For Describing Shallow Water Marine Habitats, Greg Foster

HCNSO Student Theses and Dissertations

Chapter 1

Producing thematic coral reef benthic habitat maps from single-beam acoustic backscatter has been hindered by uncertainties in interpreting the acoustic energy parameters E1 (~roughness) and E2 (~hardness), typically limiting such maps to sediment classification schemes. In this study acoustic interpretation was guided by high-resolution LIDAR (Light Detection And Ranging) bathymetry. Each acoustic record, acquired from a BioSonics DT-X echosounder and multiplexed 38 and 418 kHz transducers, was paired with a spatially-coincident value of a LIDAR-derived proxy for topographic complexity (Reef-Volume) and its membership to one of eight LIDAR-delineated benthic habitat classes. The discriminatory capabilities of the 38 and …

Consumer Return Chronology Alters Recovery Trajectory Of Stream Ecosystem Structure And Function Following Drought, Justin N. Murdock, Keith B. Gido, Walter K. Dodds, Katie N. Bertrand, Matt R. Whiles

Natural Resource Management Faculty Publications

Consumers are increasingly being recognized as important drivers of ecological succession, yet it is still hard to predict the nature and direction of consumer effects in nonequilibrium environments. We used stream consumer exclosures and large outdoor mesocosms to study the impact of macroconsumers (i.e., fish and crayfish) on recovery of intermittent prairie streams after drying. In the stream, macroconsumers altered system recovery trajectory by decreasing algal and macroinvertebrate biomass, primary productivity, and benthic nutrient uptake rates. However, macroconsumer influence was transient, and differences between exclosures and controls disappeared after 35 days. Introducing and removing macroconsumers after 28 days resulted mainly …

Interisland Variability Of Dune Plant Community Structure On Virginia's Barrier Islands, Justin K. Shafer

Biological Sciences Theses & Dissertations

The barrier islands of the Virginia Coast Reserve LTER site provide an opportunity to study interisland variability of dune plant communities. My research focused on the variation in biomass and diversity of communities among islands and dune positions. Grassy dunes of young, intermediate and old age were sampled on Smith, Hog, and Parramore Islands. Aboveground biomass was obtained from harvest plots, and roots were extracted from cores. Data were collected on depth to groundwater and total soil nitrogen. Variation in mean aboveground biomass was evident among the islands with the highest values on Hog Island, followed by Smith, then Parramore …

Diversity And Abundance Of The Dark Kangaroo Mouse, Microdipodops Megacephalus, In Communities Of Nocturnal Granivorous Rodents In Western North America, Ashley Sagers Haug

Theses and Dissertations

The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus' place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation …

Taxonomy And Applied Biogeography Of Mongolian Stoneflies (Insecta: Plecoptera), Sarah Walker Judson

Theses and Dissertations

Since the early 1900s, efforts have been made to catalogue the stoneflies of Mongolia. Taxonomic work from 1960 to 1980 greatly expanded basic lists of stoneflies in Mongolia, but no comprehensive survey or synthesis of this dispersed literature has been completed. In conjunction with a modern survey of the aquatic insects of Mongolia, we collected Plecoptera on a series of expeditions to the Selenge (north) and Altai (west) regions of Mongolia. A total of 48 species distributed in 24 genera and 8 families were documented, including 3 of the 5 Mongolian endemics, 2 new species records for Mongolia, and 1 …

Combining Local- And Large-Scale Models To Predict The Distributions Of Invasive Plant Species, Chad C. Jones, Steven A. Acker, Charles B. Halpern

Botany Faculty Publications

Habitat-distribution models are increasingly used to predict the potential distributions of invasive species and to inform monitoring. However, these models assume that species are in equilibrium with the environment, which is clearly not true for most invasive species. Although this assumption is frequently acknowledged, solutions have not been adequately addressed. There are several potential methods for improving habitat-distribution models. Models that require only presence data may be more effective for invasive species, but this assumption has rarely been tested. In addition, combining modeling types to form ‘ensemble’ models may improve the accuracy of predictions. However, even with these improvements, models …

Cruise Foraging Of Invasive Chameleon (Chamaeleo Jacksonii Xantholophus) In Hawai’I, Travis J. Hagey, Jonathan B. Losos, Luke Harmon

Biology

We quantified the foraging behavior of the Jackson’s chameleon (Chamaeleo jacksonii xantholophus), an invasive insectivorous lizard species in Hawai’i. Using video taken in the field, we focused on percent time moving, moves per minute, and movement speeds. Our results supported previous findings that chameleons are ‘‘cruise foragers’’ (sensu Butler, 2005), a foraging behavior unlike almost all other species of lizards.

Diversity And Distribution Of The Scarab Beetle Tribe Phanaeini In The Northern States Of The Brazilian Northeast (Coleoptera: Scarabaeidae: Scarabaeinae), Conrad P. D. T. Gillett, Michael P. T. Gillett, James E. D. T. Gillett, Fernando Z. Vaz-De-Mello

Insecta Mundi

The fauna of Phanaeini of the northeast of Brazil was investigated through fieldwork in the States of Ceará, Maranhão and Piauí, and through study of preserved material from other states. Seven species of Phanaeini are newly recorded from these three states. Of these, two species are also new records for the northeast region: Phanaeus melibaeus Blanchard and an unidentified Dendropaemon Perty species. A total of 13 new state records are given for eight of the 15 species of Phanaeini recorded from the northeast to date, including three new state genus records. A key is provided for identification of all species. …

Organismal Climatology: Analyzing Environmental Variability At Scales Relevant To Physiological Stress, Brian Helmuth, Bernardo R. Broitman, Lauren Yamane, Sarah E. Gilman, Katharine Mach, K. A.S. Mislan, Mark W. Denny

Faculty Publications

Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species’ range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different …

Conserving Migratory Land Birds In The New World: Do We Know Enough?, John Faaborg, Richard T. Holmes, Angela D. Anders, Keith L. Bildstein

Dartmouth Scholarship

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across …

Perspectives Of Underwater Optics In Biological Oceanography And Plankton Ecology Studies, Hans-Uwe Dahms, Jiang-Shiou Hwang

Journal of Marine Science and Technology–Taiwan

The ever expanding fields of UW (underwater) optics cover principal measurements of the optical properties of the sea, development of new methods of monitoring optical properties, techniques for measurements of organisms or structures in the sea and the development and application of optical instrumentation. In this respect, ocean optics is a multidisciplinary (and multinational) endeavour of science and engineering. Ocean optics has applications in the study of upwelling irradiance and chlorophyll concentrations in the ocean, in the penetration of solar radiation in shallow shelf seas and how this influences temperature profiles and ultimately its effect on sound propagation. Recent development …

Research Poster: Climate Change Science For Northern Nevada Educators, Melissa Slayden, Jacque Ewing-Taylor, Kelly Cannon

2010 Annual Nevada NSF EPSCoR Climate Change Conference

Research poster

Research Poster: Clark County School District Involvement In The Nsf Epscor Program, Education Component, Aubrey M. Shirk, Larry Rudd, Paul Buck

2010 Annual Nevada NSF EPSCoR Climate Change Conference

Research poster

Climate Change Education For Nevada, David M. Hassenzahl, Michael Collopy, John W. Farley, Paul Buck, Jacque Ewing-Taylor, Shama Perveen

2010 Annual Nevada NSF EPSCoR Climate Change Conference

42 PowerPoint slides Session 1: Education Convener: David Hassenzahl, UNLV Abstract: -Five Year Strategic Plan -Goal 6 - Create a scholarly environment to promote research skills and intellectual development for Nevada educators and students (K-12, undergraduate undergraduate, and graduate) -Primary Strategy - Develop educational infrastructure to train students at all levels and provide public outreach in climate change issues

Abundance Of Ammonia-Oxidizing Archaea And Bacteria Along An Estuarine Salinity Gradient In Relationship To Potential Nitrification Rates, Anne E. Bernhard, Zachary C. Landry, Alison Blevins, José R. De La Torre, Anne E. Giblin, David A. Stahl

Biology Faculty Publications

Abundance of ammonia-oxidizing Archaea (AOA) was found to be always greater than that of ammonia-oxidizing Bacteria along an estuarine salinity gradient, and AOA abundance was highest at intermediate salinity. However, AOA abundance did not correlate with potential nitrification rates. This lack of correlation may be due to methodological limitations or alternative energy sources.