Digital Commons Network^™

Mechanisms For Decisions About The Future, Jeffrey R. Stevens

Jeffrey Stevens Publications

Evolutionary and psychological perspectives on decision making remain largely separate endeavors. The bounded rationality approach integrates these two perspectives by focusing on simple, plausible mechanisms of decision making and the cognitive capacities needed to implement these mechanisms. Decisions about the future provide a class of decisions that lend themselves to a bounded rationality approach. Though many different mechanisms may exist for making decisions about the future, only a subset of these mechanisms actually require a representation of the future. The bounded rationality approach helps focus on the cognitive capacities and decision mechanisms that are necessary for a full understanding of …

Chemical Communication In A Multimodal Context, Eileen A. Hebets, Aaron S. Rundus

Eileen Hebets Publications

All animals are equipped with multiple sensory systems (e.g., visual, chemical, acoustic, tactile, electrical, thermal), and signals perceived via these sensory systems facilitate communication. Such communication often involves displays that incorporate more than one signal from more than one sensory modality, resulting in multimodal signaling. The number of empirical and theoretical studies addressing issues of multimodal signaling is ever-increasing and this chapter highlights why crustaceans, as a taxonomic group, are ideal for advancing such studies. Early classifications of multimodal signaling sought to categorize signal components as either redundant or nonredundant, while more recent classifications lay out specific hypotheses relating to …

The Degree Of Response To Increased Predation Risk Corresponds To Male Secondary Sexual Traits, Kasey Fowler-Finn, Eileen Hebets

Eileen Hebets Publications

Secondary sexual traits are expected to reflect a balance between sexual selection and natural selection. We test the hypothesis that plasticity in sexual advertisement behaviors can influence this trade-off, allowing showier traits than expected for a given level of predation risk. Specifically, we tested whether the degree of behavioral plasticity exhibited in response to chemical cues of a co-occurring predatory wolf spider corresponds to courtship rate and the degree of ornamentation in male wolf spiders. Both ornamented (brush-legged) males and non-ornamented males decreased locomotion, decreased their likelihood to court, and increased their time to initiate courtship in response to predator …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …

Development And Testing Of An Unmanned Aircraft System For Environmental Science, Jerald James Brady

Open Access Theses & Dissertations

For some environmental science applications, Unmanned Aircraft Systems (UASs) are increasingly recognized for their capacity to collect remotely sensed data in a safer, more efficient and effective manner than is permitted with manned aircraft and satellite remote sensing platforms. To date, however, technological, human, and other challenges have constrained adoption of UASs in the environmental sciences. This study developed and tested a new UAS for an archetypical environmental science research group (stakeholder) composed of non-UAS experts. Specifically, this thesis: 1) Assessed the research and operational needs of the stakeholder to determine the optimum UAS platform; 2) Developed an Unmanned Aerial …

A Taxonomic Revision Of The New World Hypoponera Santschi, 1938 (Hymenoptera: Formicidae), Shawn Thomas Dash

Open Access Theses & Dissertations

The New World taxa of the pantropic ant genus Hypoponera (Ponerinae: Ponerini) is revised for the first time. The 55 previously recognized taxa have been evaluated using morphological and, when possible, ecological and biogeographical data to resolve taxon validity and species limits. Currently I recognize 42 species of Hypoponera , a number of which are new. I propose the following taxonomic outline: Hypoponera agilis (Borgmeier), Hypoponera aliena (F. Smith), Hypoponera antoniensis (Forel) stat. nov., Hypoponera apateae sp. nov., Hypoponera capilosa sp. nov., Hypoponera clinei sp. nov., Hypoponera clavatula (Emery) [= fiebrigi (Forel) syn. nov., = neglecta (Santschi) syn. nov.], Hypoponera …

The Ecology Of Disturbances And Global Change In The Montane Grasslands Of The Nilgiris, South India, Madhusudan P. Srinivasan

University of Kentucky Doctoral Dissertations

Biodiversity rich regions worldwide face threats from various global change agents. This research quantifies environmental influences on vegetation, and the impacts of exotic woody plant invasion and anthropogenic nitrogen (N) deposition in a global biodiversity hotspot. The study was conducted in the montane grasslands of the Nilgiris, Western Ghats, and outlines potential management options for this region. Specifically, I examined (1) the role of environmental factors in influencing native plant distribution and ecosystem properties, (2) the status and impact of exotic shrub (Scotch broom, henceforth broom) invasion, (3) the role of disturbances in the success of broom, (4) the role …

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

Civil & Environmental Engineering Faculty Publications

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

Taxonomy And Ecology Of The Western Australian Soldier Crab, Mictyris Occidentalis (Crustacea: Decapoda: Brachyura: Mictyridae), Joyleen Florence Unno

Theses: Doctorates and Masters

The taxonomy and autoecology of the Western Australian soldier crab, Mictyris occidentalis Unno, 2008 is presented including a new species description, a comprehensive ichnology, sampling methods, an extensive habitat description and a decadal population dynamics study. Such a wide ranging, holistic study has not been carried out for any mictyrid specious previously. In detail, a taxonomy component compares M. occidentalis with congeners, clearly establishing it as a separate species from M. longicarpus to which it was previously referred, and the issues affecting taxonomic classification in the Mictyris genus in general are discussed. A species identification key is provided for the …

Twenty-Eight Years Of The Us-Lter Program: Experience, Results, And Research Questions, James R. Gosz, Robert B. Waide, John J. Magnuson

Long Term Ecological Research Network

The U.S. Long Term Ecological Research program (hereafter US-LTER) concentrates on ecological processes that play out at the time scales spanning decades to centuries. This focuses US-LTER research between the most common time scales for ecological studies (1-3 years; Tilman 1989; Figure 1) and the much longer temporal fact of disciplines such as paleoecology. The importance of the decade-to-century time scale is particularly evident in light of the rapid changes in ecological forcing functions that are occurring at a broad range of spatial scales (Millennium Ecosystem Assessment 2005, Intergovernmental Panel on Climate Change 2007). Long-term data sets from programs such …

Distributions Of Sharks Across A Continental Shelf In The Northern Gulf Of Mexico, J. Marcus Drymon, Sean P. Powers, John Dindo, Brian Dzwonkowski, Terry A. Henwood

University Faculty and Staff Publications

Declines in shark populations have sparked researchers and fishery managers to investigate more prudent approaches to the conservation of these fish. As managers strive to improve data collection for stock assessment, fisheries-independent surveys have expanded to include data-deficient areas such as coastal regions. To that end, a catch series from a nearshore survey off Alabama was combined with data from a concurrent offshore survey with identical methodology to examine the depth use of sharks across the continental shelf (2–366 m). The combined data set contained 22 species of sharks collected from 1995 to 2008: 21 species in the offshore data …

Landscape Factors Impacting Survival Of Sympatric Red-Necked Wallabies (Macropus Rufogriseus) And Swamp Wallabies (Wallabia Bicolor) In Urbanized Areas, Karen Zusi

Independent Study Project (ISP) Collection

Urbanization and infrastructure build-up often includes many processes that can damage the natural environment in surrounding areas. Road, powerline, and dam construction, as well as mining, drilling, and overall land-clearing, have severe impacts that resonate through the adjacent wildlife communities. Some species, however, are able to persist in the fringes of urban environments; the swamp wallaby, Wallabia bicolor, is one such example in Australia. A different species of macropod, the red-necked wallaby (Macropus rufogriseus), is similar to the swamp wallaby in many ways but has failed to persist in the outskirts of urban areas. This study aimed to quantitatively differentiate …

The Identity Of Zachaenus Roseus Cope, 1890 (Anura: Species Inquirenda), Esteban O. Lavilla, J. J. Nuñez, F. E. Rabanal, José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Zachaenus roseus Cope, 1890, has puzzled systematists working in southern South America. A single individual, the holotype, has ever been collected and this specimen is in extremely poor preservation condition. Herein, the precise location of the type locality of Z. roseus is determined based on a historical review of the literature. Furthermore, following a careful comparison with all species that inhabit the southern austral forest, and that could potentially correspond to Zachaenus roseus, we conclude that this taxon is placed in the synonymy of Eupsophus calcaratus (Günther, 1881)

Temporal And Spatial Assessment Of Evaporation, Transpiration, And Soil Moisture Redistribution, Brian M. Bird

UNLV Theses, Dissertations, Professional Papers, and Capstones

At a native stand of creosote bush (Larrea tridentata) in North Las Vegas, a rainfall simulation study was conducted over a 12 month period from October 2005 to October 2006. Simulated rainfall occurred during the winter, spring, summer, and fall periods. Rainfall simulation systems were positioned on each of 12 plots, each containing a single creosote bush. Simulated rainfall events occurred at night with multiple short pulses designed to maximize infiltration while minimizing ponding. Yearly simulated rainfall amounts were set at 0, 15, 30 and 60 cm (replicated three times) and were approximately 0, 1.5, 3.0 and 6.0 times the …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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

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

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

Our Places To Tell Stories: Preliminary Program Springs Preserve, Public Lands Institute

Our Places to Tell Stories

Our Places Tell Stories is an innovative conference for educators and others working at public lands, schools, nature centers, museums, zoos, aquaria, and all nature and heritage rich places.

This list of presentations represents a preliminary program of sessions. A final program will be emailed to all registrants prior to the conference. Thank you for your interest, and we look forward to seeing you at the Springs!

What Is The Taxonomic Identity Of Minnesota Wolves?, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The taxonomic identity of the historical and current wolf (Canis lupus L., 1758 or Canis lycaon Schreber, 1775 or their hybrids) population in Minnesota (MN) and the Great Lakes region has been, and continues to be, controversial. So too does its legal status under the U.S. Endangered Species Act. This review summarizes the morphological and genetic information about that population and concludes that historically the MN population consisted of a gray wolf (C. lupus) in the west and an eastern type (Canis lupus lycaon or C. lycaon) in the east with intergrades or hybrids between …

Linking Environmental Nutrient Enrichment And Disease Emergence In Humans And Wildlife, Pieter T. J. Johnson, Alan R. Townsend, Cory C. Cleveland, Patricia M. Glibert, Robert W. Howarth, Valerie J. Mckenzie, Eliska Rejmankova, Mary H. Ward

Ecosystem and Conservation Sciences Faculty Publications

Worldwide increases in human and wildlife diseases have challenged ecologists to understand how large-scale environmental changes affect host–parasite interactions. One of the most profound changes to Earth's ecosystems is the alteration of global nutrient cycles, including those of phosphorus (P) and especially nitrogen (N). Along with the obvious direct benefits of nutrient application for food production, anthropogenic inputs of N and P can indirectly affect the abundance of infectious and noninfectious pathogens. The mechanisms underpinning observed correlations, however, and how such patterns vary with disease type, have long remained conjectural. Here, we highlight recent experimental advances to critically evaluate the …

Fall 2010, Nsu Oceanographic Center

Currents

No abstract provided.