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Community And Functional Ecology Of Lianas In The Yasuní Forest Dynamics Plot, Amazonian Ecuador, Hugo Geovanny Romero-Saltos

Open Access Dissertations

I studied the community of lianas in the Yasuní Forest Dynamics Plot (YFDP), in Amazonian Ecuador. I found that species diversity of lianas in valley habitat was higher than in ridge habitat, but liana abundance was similar. I also found that community structure (species composition and their abundances) of lianas in ridge was distinct from that in valley because of the differential distribution and abundance of certain species along the topographic gradient. In an attempt to explain this phenomenon deterministically, I took two approaches: (1) to explore if trait expression of leaf-based traits, wood specific gravity and stem growth rate …

Fire Ant Decapitating Fly Cooperative Release Programs (1994-2008): Two Pseudacteon Species, P. Tricuspis And P. Curvatus, Rapidly Expand Across Imported Fire Ant Populations In The Southeastern United States, Anne Marie A. Callcott, Sanford D. Porter, Ronald D. Weeks, L. C. Fudd Graham, Seth J. Johnson, Lawrence E. Gilbert

Faculty Publications

Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about …

Height-Diameter Allometry Of Tropical Forest Trees, T. R. Feldpausch, L. Banin, O. L. Phillips, T. R. Baker, S. L. Lewis, C. A. Quesada, K. Affum-Baffoe, E. J. M. M. Arets, N. J. Berry, M. Bird, E. S. Brondizio, P. De Camargo, J. Chave, G. Djagbletey, T. F. Domingues, M. Drescher, P. M. Fearnside, M. B. Franca, N. M. Fyllas, G. Lopez-Gonzalez, A. Hladik, N. Higuchi, M. O. Hunter, Michael W. Palace

Faculty Publications

Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were:

1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap).

2. to ascertain if the H:D relationship is modulated by climate and/or forest …

Changes In Leaf Morphology, Photosynthesis And Nitrogen Content In Two Coastal Shrubs, Elizabeth Kost

Theses and Dissertations

It is important to understand mechanisms that facilitate expansion of two common shrubs, Morella cerifera and Baccharis halimifolia in coastal environments. The purpose of my study was to investigate the physiological and structural changes that occur as leaves age. Photosynthesis, incident light, chlorophyll, and leaf C:N ratios were quantified for young, intermediate, and old leaves (distal, central and proximal leaves, respectively). Leaf structural differences were also compared. Leaves did not change morphologically with age. Light decreased with leaf age and during winter months. Photosynthesis showed no seasonal or age related patterns. Chlorophyll increased initially and then declined with age due …

From Growth To Extinction: Explored By Life History And Metabolic Theory, Wenyun Zuo

Biology ETDs

The laws of energy and material conservation are fundamental principles across various scales and systems. Based on the conservation laws, I derive several theoretical models to understand mechanisms behind the energy budget of ontogenetic growth and the pattern of the late Pleistocene extinction of megafauna in the Americas. First, I present a model, empirically grounded in data from birds and mammals, that correctly predicts how growing animals allocate food energy between synthesis of new biomass and maintenance of existing biomass. Previous energy budget models have typically been based on rates of either food consumption or metabolic energy expenditure. The model …

Summaries Of Arkansas Cotton Research 2010, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

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 …

Optimal Foraging In Leafcutter Ants (Atta Cephalotes) Selection Of Leaves Based On Proximity To The Nest, May 2011, Robert O. Snowden

Monteverde Institute: Tropical Ecology and Conservation

The foraging tendencies of Atta cephalotes, a leaf-cutting ant, have been widely studied. Optimal foraging theory dictates that ants should maximize rate of energy intake while minimizing costs by harvesting from suitable food sources closer to the nest. However, actual foraging patterns are more disparate and do not always reflect optimal strategies. Here I measure harvesting rates and recruitment speeds at different distances from the nest of A. cephalotes colonies by offering six leaf disk samples every 15 minutes at 5, 10, and 15 meters from the nest entrance. Harvesting rate was significantly higher closer to the nest, with 54% …

Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold

Biological Sciences Faculty Publications

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful …

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 …

Establishing Weed Prevention Areas And Evaluating Their Impact, Stephanie Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The spread of invasive weeds continues to be a serious economic and environmental threat. Weed prevention has the potential to stop weeds before they become well established in an area conserving time, energy, and resources. Unfortunately, weed prevention is often overlooked. Weed Prevention Areas (WPAs) are a relatively new tool developed to help improve the application of weed prevention. They are cooperatively managed areas that focus on implementing prevention and early detection strategies at a community level. The purpose of this research was to establish baseline data that will be used to evaluate the overall effectiveness of the WPA concept, …

Riparian Bird-Habitat Association Models: A Framework For Informing Management And Developing Restoration Guidelines In Utah, Hillary M. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Approximately 75% of the avian species in Utah use riparian habitats at some time during their life cycles and at least 80% of this habitat in Utah has been lost or altered since settlement; currently 0.6% of land cover in Utah is considered riparian. In 1992, with the support of Utah Partner's in Flight, the Utah Division of Wildlife Resources began a statewide neotropical migratory bird (NTMB) and habitat monitoring program to assess the status of bird populations at 31 sites. Additional sites (up to 52) were added in later years; bird and habitat assessments at 37 riparian sites have …

15n Tracer And Modeling Analyses Of Nutrient Transport Through Lakes In A Subalpine Watershed, David M. Epstein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lakes have historically been overlooked as important nutrient processors within their watersheds. In general ecologists have focused on streams as zones of uptake and transformation, while viewing lakes as simple nutrient traps. However, recent research has highlighted the large influence that lakes may have on water chemistry within their watersheds. Within the field of limnology, researchers have traditionally focused on the pelagic zone for in-lake production. Further research in shallow lakes has highlighted the role benthic production within the littoral zone plays in the lake ecosystem. The greater influence of lakes is highlighted when comparing watersheds containing lakes with watersheds …

The Decline And Conservation Status Of North American Bumble Bees, Jonathan Berenguer Koch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. …

An Ecological, Genetic, And Reproductive Study Of Big Bluestem (Andropogon Gerardii) Populations In The Carolinas, Robert Tompkins

All Dissertations

ABSTRACT
AN ECOLOGICAL, GENETIC, AND REPRODUCTIVE STUDY OF BIG BLUESTEM (ANDROPOGON GERARDII) POPULATIONS IN THE CAROLINAS
Andropogon gerardii (Big Bluestem) is a dominant grass of the North American tallgrass prairie and is also found in remnant populations in the eastern U.S., including North and South Carolina. This research included a systematic study of the ecology, genetics, and reproductive potential within and among A. gerardii populations in the Carolinas. Floristic composition and edaphic (soil) features were characterized for eight A. gerardii populations across various physiographic regions of North and South Carolina. A total of 362 quadrats (1 m x 1 m) …

The Relationships Among Plant Cover, Density, Seed Rain, And Dispersal Of Bromus Tectorum In High-Elevation Populations, Andrew R. Kanarek, Rebecca Hufft Kao

Western North American Naturalist

The invasive species Bromus tectorum L. is recognized as one of the most ecologically and economically devastating weeds in the western United States. Although B. tectorumhas been studied extensively, few studies have examined its dispersal and spread. We collected data from sites with B. tectorum in and around Rocky Mountain National Park to quantify the relationships between plant cover/density and seed rain and dispersal distance. Results suggest that there is a positive relationship between density within a patch and local seed rain and that B. tectorum exhibits relatively limited short-distance dispersal (where seeds fell in close proximity to plants …

Aurora Vol. 03 No. 2 (Spring 2011), N/A N/A

Aurora

No abstract provided.

The Hydrologic Regime At Sub-Arctic And Arctic Watersheds: Present And Projected, Anna K. Liljedahl

Engineering

The wetlands in the Arctic Coastal Plain, Northern Alaska, support a multitude of wildlife and natural resources that depend upon the abundance of water. Observations and climate model simulations show that surface air temperature over the Alaskan arctic coast has risen in recent history. Thus a growing need exists to assess how the hydrology of these arctic wetlands will respond to the warming climate. A synthesis study was conducted combining the analysis of an extensive field campaign, which includes direct measurements of all components of the water balance, with a physically-based hydrologic model forced by downscaled climate projections. Currently, these …

Arctic Alaskan Shrub Growth, Distribution, And Relationships To Landscape Processes And Climate During The 20th Century, Ken D. Tape

Biological Sciences

The primary change underway in the tundra of Arctic Alaska is the increase in air temperature and expansion of deciduous shrubs since 1980. I explored relationships between shrub expansion and relevant ecosystem properties such as climate, soil characteristics, erosion, and herbivory. Alnus viridis ssp. fruticosa (Siberian alder) shrubs located along streams, rock outcrops, or other features with active disturbance regimes showed a positive correlation between growth ring widths and March through July air temperature. Climate-growth relationships were much weaker for alder in adjacent tussock tundra. Additionally, tussock tundra sites had different vegetation composition, shallower thaw, lower mean annual ground temperature, …

Neonatal Resuscitation And Immediate Newborn Assessment And Stimulation For The Prevention Of Neonatal Deaths: A Systematic Review, Meta-Analysis And Delphi Estimation Of Mortality Effect, Anne C. C. Lee, Simon Cousens, Stephen N. Wall, Susan Niermeyer, Gary L. Darmstadt, Waldemar A. Carlo, William J. Keenan, Zulfiqar Ahmed Bhutta, Christopher Gill, Joy E. Lawn

Woman and Child Health

Background: Of 136 million babies born annually, around 10 million require assistance to breathe. Each year 814,000 neonatal deaths result from intrapartum-related events in term babies (previously "birth asphyxia") and 1.03 million from complications of prematurity. No systematic assessment of mortality reduction from tactile stimulation or resuscitation has been published. Objective:To estimate the mortality effect of immediate newborn assessment and stimulation, and basic resuscitation on neonatal deaths due to term intrapartum-related events or preterm birth, for facility and home births.

Methods:

We conducted systematic reviews for studies reporting relevant mortality or morbidity outcomes. Evidence was assessed using GRADE criteria …

The Effect Of Providing Skilled Birth Attendance And Emergency Obstetric Care In Preventing Stillbirths, Mohammad Yawar Yakoob, Mahrukh Ayesha Ali, Mohammad Usman Ali, Aamer Imdad, Joy E. Lawn, Nynke Van Den Broek, Zulfiqar Ahmed Bhutta

Woman and Child Health

Background:Of the global burden of 2.6 million stillbirths, around 1.2 million occur during labour i.e. are intrapartum deaths. In low-/middle-income countries, a significant proportion of women give birth at home, usually in the absence of a skilled birth attendant. This review discusses the impact of skilled birth attendance (SBA) and the provision of Emergency Obstetric Care (EOC) on stillbirths and perinatal mortality.

Methods:

A systematic literature search was performed on PubMed/MEDLINE, Cochrane Database and the WHO regional libraries. Data of all eligible studies were extracted into a standardized Excel sheet containing variables such as participants' characteristics, sample size, location, …

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 …

Review Of Acanthocephala (Hemiptera: Heteroptera: Coreidae) Of America North Of Mexico With A Key To Species, J. E. Mcpherson, Richard J. Packauskas Ph.D., Robert W. Sites, Steven J. Taylor, C. Scott Bundy, Jeffrey D. Bradshaw, Paula Levin Mitchell

Biological Sciences Faculty Publications

A review of Acanthocephala of America north of Mexico is presented with an updated key to species. A. confraterna is considered a junior synonym of A. terminalis, thus reducing the number of known species in this region from five to four. New state and country records are presented.

Predators Of Enashiva: A Survey Of Occurrence & Distribution, Adrienne Fisk Bowles

Independent Study Project (ISP) Collection

This study was conducted during a period of 16 days (April 10 to April 26, 2011) at the Enashiva Nature Refuge in Northern Tanzania. It was a modified repeat study, using the same methodologies of a mammal survey conducted in November 2009, however this study only focused on occurrence and distribution of predators in the highest trophic level and accounted for reptile and birds, in addition to mammals. Based upon the findings of the November 2009 study, it was hypothesized that the woodland would have the highest predator species richness. This hypothesis was supported by the data; the woodland habitat …

Rippled Scour Depressions Add Ecologically Significant Heterogeneity To Soft Sediment Habitats On The Continental Shelf, Todd Russell Hallenbeck

SNS Master's Theses

Comprehensive high-resolution seafloor mapping of California's state waters have revealed rippled scour depressions (RSD) to be one of the most abundant and widespread habitats of the inner continental shelf. These sharply delineated elongate features range in size from 1 OO's to 1000's of m2 in aerial extent and are characterized by 30 to 50 cm deep depressions of coarser sediments and longer period bedforms than found on the surrounding seabed. Although RSDs have been identified on many of the world's continental margins, previous stUdies focused on their geomorphology and dynamics, leaving the ecological influence and associated biological communities of RSDs …

Promoting At-Risk Preschool Children’S Comprehension Through Research-Based Strategy Instruction, Andrea Debruin-Parecki, Kathryn Squibb

Reading Horizons: A Journal of Literacy and Language Arts

Young children living in poor urban neighborhoods are often at risk for reading difficulties, in part because developing listening comprehension strategies and vocabulary knowledge may not be a priority in their prekindergarten classrooms, whose curriculums typically focus heavily on phonological awareness and alphabet knowledge. Prereading comprehension strategies are instrumental in developing skilled readers and significant to future academic success; their absence in preschool classrooms may contribute to challenges children face while learning to read. This article examines an exploratory investigation in two low-income public prekindergarten classrooms where children received an eight-week intervention to develop intentional comprehension strategies. Implications of this …

Review Of The Leadership Of George Bush: An Insider's View Of The Forty-First President. By Roman Popadiuk, Caroline Heldman

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The Leadership of George Bush is infused with a sentimentality exemplified by the book's opening statement describing the Bushes' emotional response to Bush 43's election to the presidency: "George Bush sat straight up, his back rigid but his chest heaving slightly as he sought to hold back tears. Barbara Bush sat quietly, unmovable, a glint of satisfaction and pride sparkling in her eyes." Despite the author's proximity and long-time affiliation, the book provides scant new information about Bush 41 's presidency, mostly because the author fails to connect it with larger literatures on presidential leadership and executive management. Instead, it …

Health And Fertility Implications Related To Seasonal Changes In Kidney Fat Index Of White-Tailed Jackrabbits In South Dakota, Dustin Schaible, Charles D. Dieter

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

White-tailed jackrabbit (Lepus townsendii) populations in the Northern Plains have been in a general decline for the past decade or longer. A suggested reason for this population decline was reduced body condition of individual jackrabbits due to habitat changes. In order to evaluate body condition, we determined the kidney fat index of 314 white-tailed jackrabbits harvested in 44 counties throughout South Dakota. We removed and weighed kidneys and all perirenal fat associated with the kidneys from collected jackrabbits. We measured kidney weight to determine times of high metabolic activity as indicated by an increase in mass. Body condition was …