Digital Commons Network^™

On Estimating The Exponent Of Power-Law Frequency Distributions, Ethan P. White, B. J. Enquist, J. L. Green

Biology Faculty Publications

Power-law frequency distributions characterize a wide array of natural phenomena. In ecology, biology, and many physical and social sciences, the exponents of these power-laws are estimated to draw inference about the processes underlying the phenomenon, to test theoretical models, and to scale up from local observations to global patterns. Therefore, it is essential that these exponents be estimated accurately. Unfortunately, the binning-based methods traditionally utilized in ecology and other disciplines perform quite poorly. Here we discuss more sophisticated methods for fitting these exponents based on cumulative distribution functions and maximum likelihood estimation. We illustrate their superior performance at estimating known …

Ecology And Morphological Comparison Between Rough Greensnakes (Opheodrys A. Aestivus) And Eastern Smooth Greensnakes (Opheodrys V. Vernalis) In West Virginia, Timothy Earl Baldwin

Theses, Dissertations and Capstones

Since 1971, documented Rough Greensnake (Opheodrys aestivus) occurrences in West Virginia have declined from approximately 100 to less than 20 occurrences in the last 10 years. In contrast to the decline of Rough Greensnakes in WV, Smooth Greensnake (O. vernalis) populations appear to be stable over the same period of time. Historic sites from the West Virginia Biological Survey were cross referenced with habitat descriptions in published literature to establish research locations. One hundred nineteen Rough and Smooth Greensnakes were measured for snout-vent length and total body length, and of these, 78 were measured in detail for external head morphology …

Resolving The 150 Year Debate Over The Ecological History Of The Common Periwinkle Snail, Littorina Littorea, In Northeast North America, April M H Blakeslee

Doctoral Dissertations

Littorina littorea (common periwinkle snail) is highly abundant in both Europe and North America. A known native of Europe, its presence in North America has been the subject of a one-hundred year debate. Prior published work attempting to resolve its cryptogenic (=uncertain origin) status with historical, archaeological, ecological and/or genetic data were not successful. I therefore included novel parasite and molecular evidence to definitively resolve L. littorea's North American cryptogenic status.

First, I explored trematode species richness patterns in European versus North American L. littorea and two co-occurring native congeners, L. saxatilis and L. obtusata. Through extensive field and literature …

Field Efficiency And Bias Of Several Methods For Downed Wood And Snag Inventory In Western North American Forests, Robert Scott Kenning

Master's Theses and Capstones

Coarse woody debris (CWD)---downed forest wood and snags---has been afforded increasing attention in the past decade as studies illuminate the role of dead wood in the study of global carbon cycling, wildlife, forest fire, and soil ecology. Accordingly, the need for efficient sampling methods of CWD has grown. This study compares the field efficiency and bias of seven traditional and novel sampling techniques. Methods were tested in 14 forest stands across 3 broad study regions---alpine and ponderosa forests in Colorado and coastal rainforest in British Columbia.

For sampling downed wood volume, perpendicular distance sampling (PDS) proves to be the most …

Random Forests For Classification In Ecology, D. R. Cutler, Thomas C. Edwards Jr., Karen H. Beard, A. Cutler, K. T. Hess, J. C. Gibson, J. J. Lawler

Wildland Resources Faculty Publications

Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy; (2) a novel method of determining variable importance; (3) ability to model complex interactions among predictor variables; (4) flexibility to perform several types of statistical data analysis, including regression, classification, survival analysis, and unsupervised learning; and (5) an algorithm for imputing missing values. We compared the accuracies of RF and …

An Interpolation Method For Stream Habitat Assessments With Reference To The Crystal Darter, Kenneth Richard Sheehan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Crystallaria asprella spp. (Elk River crystal darter) is documented only in Elk River, West Virginia. Little life history detail is known about this lotic, benthic-dependent species. Previous studies have led to a very basic understanding of the use of depth, flow and substrate of the crystal darter (Crystallaria asprella), and less is known about the Elk River crystal darter. Due to substrate-specificity in crystal darters (which reportedly bury in sand), a study concerning benthic stream habitat modeling was undertaken. Substrate and depth modeling using >5% of an area sampled at a resolution of 0.093 m2 square spatial data in a …

Comparative Pollen Foraging Of Africanized And European Honeybees In A Non-Agricultural Environment, Ruben Ruiz

Theses and Dissertations - UTB/UTPA

With the advent of the Africanized honeybee, ways to differentiate it from the European honeybee have been greatly sought in attempts to better understand the role of Africanized bees in pollination. Pollen collecting strategies for both honeybee subspecies have been explored in attempts to exploit their pollinating capabilities. This project examined pollen collected by honeybees from feral and managed European and Africanized colonies in a relatively isolated site. Paired European and Africanized honeybee colonies were used to obtain pollen foragers. Through acetolysis (series acidified Acetic Anhydride washings); the collected pollen from the individual foragers was treated and observed with light …

Spatial Autocorrelation And Pseudoreplication In Fire Ecology, Amanda L. Bataineh, Brian P. Oswald, Mohammad M. Bataineh, Daniel Unger, I-Kuai Hung, Daniel Scognamillo

Faculty Publications

Fire ecologists face many challenges regarding the statistical analyses of their studies. Hurlbert (1984) brought the problem of pseudoreplication to the scientific community’s attention in the mid 1980’s. Now, there is a new issue in the form of spatial autocorrelation. Spatial autocorrelation, if present, violates the traditional statistical assumption of observational independence. What, if anything, can the fire ecology community do about this new problem? An understanding of spatial autocorrelation, and knowledge of available methods used to reduce the effect of spatial autocorrelation and pseudoreplication will greatly assist fire ecology researchers.

Tropical Forest Structure: Ground Measurements Of Coarse Necromass And Satellite Observations Of Crown Geometry, Michael W. Palace

Doctoral Dissertations

Forests are structurally diverse, but these structures derive from the same processes of disturbance and growth. Understanding forest structure can help unlock the history, function, and future of a forested ecosystem. Components of forest structure include tree size distributions, foliage distributions and variation in canopy density, and coarse woody debris (coarse necromass). Tropical rainforests are structurally the most complex of all ecosystems. In addition to having high biological diversity, Amazon forests are marked by complex vegetation dynamics and a diverse forest stand structures, which play an important role in the interactions of water and carbon between the biosphere and atmosphere. …

Speciation In Duckweeds (Lemnaceae): Phylogenetic And Ecological Inferences, Daniel J. Crawford, Elias Landolt, Donald H. Les, Rebecca T. Kimball

Aliso: A Journal of Systematic and Floristic Botany

Species of duckweeds (Letnnaceae) that were resolved as sister taxa in a phylogeny based on combined molecular and non-molecular data were compared for morphological, physiological, and ecological attributes to infer factors important in the initial divergence leading to speciation. The ability to survive extreme conditions such as desiccation and cold temperatures is the most common difference identified between species. Two morphological characters facilitating survival in extreme environments are production of special resting buds called turions and increased seed production. The prevalent geographic pattern for species pairs consists of one restricted species occurring on the periphery of a more widespread taxon; …

A Test Of The Nutrient-Productivity Model In The Gulf Of Maine Using The Intertidal Mussel Mytilus Edulis, Meredith A. Bailey

Master's Theses and Capstones

Historical concepts of top-down control (predator-prey interactions) on rocky intertidal community structure have transitioned to studies on bottom-up effects (nutrient supply and larval transport) as significant factors affecting rocky intertidal community structure. Studies performed on rocky intertidal locations along the Gulf of Maine (GOM) at multiple sites and seasons in 2004 and 2006 examined the ecology of Mytilus edulis populations by measuring size frequency distributions, diet quality (stable isotope composition) and physiological performance of individuals using condition indices and RNA/DNA ratios. Data were correlated to satellite imagery for sea surface temperature and chlorophyll a concentration and individuals were genetically tested …

Art Informing Science Education: The Potential Contributions Of Ornithological Illustration To Ecology Education, Vanessa Hunt

LSU Doctoral Dissertations

Birds serve as an excellent group of organisms from which to introduce the study of ecology, being of inherent aesthetic interest to many otherwise uninterested in science, and are also ubiquitous in the immediate environment of many students. By extension, images of birds might serve as a valuable resource for the ecology educator, and bird artists – as a subset of ecologists - might provide useful models for expertise in ecology. This study examines the potential contributions of bird artists and bird art to education in ecology at the high school and college level. Eight contemporary bird artists were interviewed …

Effects Of Forest Clear Cutting On Spotted Salamander ( Ambystoma Maculatum) Migration, Jessica Susannah Veysey

Master's Theses and Capstones

Upland buffer zones are a proposed management tool for vernal-pool-breeding amphibians. Substantial validation of buffers, via experimental upland habitat disturbance, is lacking. Specifically, no studies have examined immediate effects of clear cutting on spotted salamander (Ambystoma maculatum ) migration. I used clear cutting to experimentally manipulate upland buffer widths at 11 vernal pools. I then radiotracked 40 adult spotted salamanders at these pools, and modeled their migration with mixed-effects regression. Mean maximum distance from the pool was 106.0 +/- 15.4 m (range = 1.6 to 427.6 m). At clear cut-treatment pools, mean percent of time in the cut was 27.2 …

Nesting Success And Nest Site Characteristics Of Four Thrush Species On A Managed Forest, Rachel Dellinger

Graduate Theses, Dissertations, and Problem Reports (ETD)

Four thrush species breed sympatrically in the Allegheny Mountain region of West Virginia, U.S.A.: American Robin (Turdus migratorius), Hermit Thrush (Catharus guttatus), Veery (Catharus fuscescens), and Wood Thrush (Hylocichla mustelina). How nesting habitat is partitioned among the species is unclear, as is the effect of logging activities on the guild. My objectives were to identify nesting habitat characteristics that are partitioned among the species and to determine their effects on nest survival.;I conducted point count surveys and monitored nests of four thrush species on a managed forest. I measured habitat variables at three scales: (1) nest substrate, (2) nest site, …

An Ecological Study Of Panax Quinquefolius In Central Appalachia: Seedling Growth, Harvest Impacts And Geographic Variation In Demography, Martha E. Van Der Voort

Graduate Theses, Dissertations, and Problem Reports (ETD)

American ginseng (Panax quinquefolius L.) is a long-lived, slow-maturing understory perennial herb found in eastern North American forests. The economic value of P. quinquefolius on the world market has remained strong for nearly 300 years. It has high economic and social value in the central Appalachians as well. Persistent harvest of ginseng combined with habitat loss has reduced populations in the wild, threatening the future of the species and its continued harvest. American ginseng was placed on the CITES Appendix II list in 1973 due to population declines. These concerns led to a series of studies investigating the population dynamics …

Demography And Genetic Structure Of An Allegheny Woodrat Population In Northcentral West Virginia, Mary Elizabeth Manjerovic

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Allegheny woodrat (Neotoma magister) occurs throughout the Appalachian Mountains forming isolated colonies in rock outcrops, cliffs, and caves. In the past 20--30 years, populations along the northern and western peripheries of the range have experienced drastic declines. There have been suggested reasons for this decline but a lack of long-term data has prevented application of specific management actions. In recent years, there has been more insight into population structure, gene flow, and relatedness among colonies. The objectives of my study were to examine these factors at a localized level to further assist with future management decisions.;Using data collected over …

Ten Suggestions To Strengthen The Science Of Ecology, Gary E. Belovsky, Daniel B. Botkin, Todd A. Crowl, Kenneth W. Cummins, Jerry F. Franklin, Malcolm L. Hunter, Anthony Joern, David B. Lindenmayer, James A. Macmahon, Chris R. Margules, J. Michael Scott

Papers in Ecology

There are few well-documented, general ecological principles that can be applied to pressing environmental issues. When they discuss them at all, ecologists often disagree about the relative importance of different aspects of the science’s original and still important issues. It may be that the sum of ecological science is not open to universal statements because of the wide range of organizational, spatial, and temporal phenomena, as well as the sheer number of possible interactions.We believe, however, that the search for general principles has been inadequate to establish the extent to which generalities are possible.We suggest that ecologists may need to …

Morphological, Anatomical And Ecological Studies On Tulipa Armena Boiss. Var. Lycica (Baker) Marais (Liliaceae), Ati̇la Ocak, Sevi̇m Alan, Ebru Ataşlar

Turkish Journal of Botany

This study presents investigations into the morphological, anatomical and ecological features of Tulipa armena Boiss. var. lycica (Baker) Marais. T. armena var. lycica, an endemic species which was collected from the Eskişehir, Alpu-Bozan plantation area and from Kunduzlar Dam and its environs. The species is a new record for Eskişehir. For morphological studies a description and illustrations of T. armena var. lycica are given. The morphological differences were compared with the Flora of Turkey. For anatomical studies, cross-sections of the root, stem and leaves and surface sections of the leaves of T. armena var. lycica are investigated for the first …

The Ecology Of Interorganizational Information Sharing, Jane Fedorowicz, Janis L. Gogan, Amy W. Ray

Journal of International Technology and Information Management

Increasingly, companies use interorganizational information systems to support business process partnerships, such as automatic replenishment systems and other supply chain initiatives, invoicing and payments, and insurance claims processing. Inter-firm networking in turn can increase the visibility of information generated and used by business partners. These business partners may experience intended and unintended impacts from the changes in the partnering relationship, in effect altering the ecology of the organization. Yet IT researchers rarely study an organization’s ecology, focusing instead on impacts upon internal processes. Our goal in this paper is to propose a definition of interorganizational information ecology, to provide IT …

Ecology And Management Of Raccoons Within An Intensively Managed Forest In The Central Appalachians, Sheldon F. Owen

Graduate Theses, Dissertations, and Problem Reports (ETD)

The raccoon (Procyon lotor), a generalist meso-predator, is commonly found throughout the eastern United States. Many researchers have examined the ecology and spatial requirements of raccoons in agricultural and wetland areas of the mid-western and southeastern United States. However, no studies have quantitatively examined raccoon habits in the forested central Appalachians and their response to forest management. During the fall of 2000 through the spring of 2003, I monitored the spatial movements and den site selection of raccoons within an intensively managed forest.;I investigated the occurrence of raccoon roundworm (Baylisascaris procyonis) in raccoons (Procyon lotor) within my study area. I …

Censusing And Modeling The Dynamics Of A Population Of Eastern Hemlock (Tsuga Canadensis L.) Using Remote Sensing, W. Robert Lamar

Graduate Theses, Dissertations, and Problem Reports (ETD)

A population of eastern hemlock (Tsuga canadensis L.) was censused from the ground using traditional field methods and from the air using large scale, high-resolution, aerial imagery in the early spring of 1997, 1998 and 1999. A manual crown survey map of the population, prepared from aerial imagery, was compared to a traditional field census. Over 60% of the individuals measured on the ground were not detected in the aerial census. Tree size, crown density and crown position all played roles in determining a crown's visibility from the air. Nearly all large, upper canopy hemlocks were visible in the aerial …

The Treeline Ecotone In Interior Alaska: From Theory To Planning And The Ecology In Between, Martin Wilmking

Forest Sciences

Treelines have been the focus of intense research for nearly a hundred years, also because they represent one of the most visible boundaries between two ecological systems. In recent years however, treelines have been studied, because changes in forest ecosystems due to global change, e.g. treeline movement, are expected to manifest first in these areas. This dissertation focuses on the elevational and latitudinal treelines bordering the boreal forest of interior Alaska. After development of a conceptional model of ecotones as three-dimensional spaces between ecosystems, we offer a historical perspective on treeline research and its broader impact in the Brooks Range, …

Characterization Of Prokaryotic Diversity In A Chlorinated Solvent-Contaminated Bedrock Aquifer Using Denaturing Gradient Gel Electrophoresis, Ribosomal Dna Sequencing, And Real Time Pcr, Walid Naser

Doctoral Dissertations

A culture-independent molecular phylogenetic approach was implemented to investigate spatial and temporal variations in microbial diversity and abundance in a chlorinated solvent-contaminated bedrock aquifer. Core and groundwater samples were collected from several boreholes and included the following samples: (1) groundwater that was associated with the core, (2) open fractures and (3) partially mineralized sealed fractures (PMSF) exposed by striking the core with a surface-sterilized geology hammer. DNA representing the attached and unattached microbial communities was extracted from these samples, and the 16S rRNA gene was amplified with primers specific for Bacteria, Archaea, sulfate reducers, Geobacteraceae family, Dehalorespirers (Dehalococcoides sp. and …

Factors Affecting Plant Community Composition And Dynamics In The Ossipee Pine Barrens, New Hampshire, Lauren Fredrick Howard

Doctoral Dissertations

Forty-one 0.25 ha sites were sampled in the Ossipee Pine Barrens to identify and describe tree community types and investigate factors controlling forest composition and dynamics. Every site had three site-time assemblages (STA's) representing past, present, and future trees. Past (1952) vegetation was calculated based on reverse growth estimates of current stems and stumps. Future (2052) vegetation was predicted by current sapling (<10 cm dbh and ≥1 m tall) relative densities.

Cluster analysis produced three community types from 121 STA's: pitch pine, mixed pine-hardwoods, and red maple. Pitch pine communities comprised 63% of sites in 1952, but declined since. Mixed pine-hardwoods peaked at 58% in 2002, but were …

Second Natures: Media, Masculinity And The Natural World In Twentieth-Century American Literature And Film., Jeanne E. Hamming

Graduate Theses, Dissertations, and Problem Reports (ETD)

This multidisciplinary dissertation examines the cultural anxieties associated with masculine identity in relation to both technology and nature in key literary texts and contemporary films of the twentieth-century: Ray Bradbury's “The Veldt” and The Martian Chronicles, Philip K. Dick's Do Androids Dream of Electric Sheep?, James Dickey's Deliverance , Don DeLillo's White Noise, Fight Club, American Psycho, Brazil, 12 Monkeys, and Dark City. Exploring the theoretical intersections of technoculture, ecocriticism, and gender studies, this dissertation analyzes the relationship between masculine identity and nature, as it is mediated by American technoculture. This relationship is marked by a discernible cultural malaise—a sense …

Fictions Of Nature: Ecology, Science, And Culture In Twentieth-Century British Literature., Neal Bukeavich

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation examines twentieth-century British fiction concerned with humankind's interactions with the nonhuman world. I analyze a range of literary works, including H. G. Wells's The Food of the Gods (1903), D. H. Lawrence's The Rainbow (1915), Women in Love (1920), and Lady Chatterley's Lover (1928), John Brunner's Stand on Zanzibar (1968), Graham Swift's Waterland (1983), and J. G. Ballard's Rushing to Paradise (1994). This body of literature remains largely unexamined for its treatments of ecological issues and belongs to a national history deeply implicated in local and global environmental change. Moreover, my consideration of this literary tradition marks a …

The Ecology Of Lianas And Their Role In Forests, Stefan A. Schnitzer, Frans Bongers

Biological Sciences Faculty Research and Publications

Recent studies have demonstrated the increasingly important role of lianas (woody vines) in forest regeneration, species diversity and ecosystem-level processes, particularly in the tropics. Mechanisms responsible for the maintenance of liana species diversity could yield new insights into the maintenance of overall species diversity. Lianas contribute to forest regeneration and competition, not only by competing directly with trees, but also by differentially affecting tree species and thus changing how trees compete among themselves. In addition, they contribute considerably to ecosystem-level processes, such as whole-forest transpiration and carbon sequestration. As the rate of tropical forest disturbance increases, they are likely to …

Statmod: A Tool For Interfacing Arcview® Gis With Statistical Software To Facilitate Predictive Ecological Modeling, Christine M. Garrard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As geographical information systems and spatial data become more accessible, predictive spatial modeling in ecology is becoming more common. Unfortunately, not all ecologists possess the necessary skills to successfully combine statistical models and geographical information systems. In response to this problem, I wrote an extension for ArcView^® GIS called StatMod. This extension interfaces ArcView GIS with SAS^® and S-PLUS^® statistical software and walks the user through creating and mapping logistic regression and classification and regression tree models.

StatMod was then used to run a series of analyses that would have been difficult without such a tool. A …

The Role Of Copepods In The Distribution Of Hydrocarbons: An Experimental Approach, Switgard Duesterloh

Fisheries

Copepods may provide a significant pathway for the concentration and transfer of polyaromatic compounds (PAC) to higher trophic level consumers. PAC dissolved from weathered crude oil are more persistent in the environment and have much higher toxicity than the lighter, more volatile fractions of crude oil. Because of their polarity, PAC tend to accumulate in bio-lipids. Subarctic copepod species can contain up to 80% of their body dry weight in lipids and have a high surface area to volume ratio. Thus, PAC accumulation is rapid and bioaccumulation factors are in the order of 500--8000, depending upon species and lipid content. …

Ecology And Growth Of Tamias Palmeri And Testing Of A Protocol To Monitor Habitat Relationships, Christopher Eric Lowrey

UNLV Retrospective Theses & Dissertations

The ecology of Tamias palmeri is investigated. Presence-absence and relative abundance of T. palmeri are related to principle component scores of habitat variables using logistic regression and multiple linear regression, respectively. Relative abundance of Tamias palmeri estimated with live capture-recapture was positively correlated with shrub cover and negatively correlated with slope. Timing of emergence from dens by juveniles was earlier and weights of juveniles were greater in ravine areas as compared to upslope areas. Track plates were not correlated with trap captures. Track plate success was not correlated with habitat variables. The results of this study were used to build …