Digital Commons Network^™

Quantifying The Adaptive Cycle, David G. Angeler, Craig R. Allen, Ahjond S. Garmestani, Lance H. Gunderson, Olle Hjerne, Monika Winder

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term …

The Effect Of Insularity On The Seasonal Population Structure Of Mesobuthus Gibbosus (Scorpiones: Buthidae), Dimitris Kaltsas, Iasmi Stathi, Moysis Mylonas

Euscorpius

We compared the population structure of Mesobuthus gibbosus from autumn to mid-summer at two similar phryganic ecosystems, one in continental Greece (Thessalia, near Volos city) and one in insular Greece (eastern Crete). Data were collected monthly using the capture-recapture method. At both sites, density was low during the cold period and increased towards summer. During the samplings, only a small percentage of each population was present. Population density and co-occurrence of scorpions with scorpions or other animals was higher in Crete than in Volos, probably due to the higher inter- and intraspecific competition in Volos. The population structure of the …

Divergent Responses Of Cryptic Invasive Watermilfoil To Treatment With Auxinic Herbicides In A Large Michigan Lake, Syndell R. Parks

Masters Theses

Invasive plants are a major concern for environmental managers. Cryptic invasive taxa present additional challenges because of their potential to respond differently to management efforts. Invasive Eurasian watermilfoil (Myriophyllum spicatum) and hybrid watermilfoil (Myriophyllum spicatum x Myriophyllum sibiricum) cannot be reliably distinguished based on morphological characters and are therefore cryptic taxa. Laboratory studies show that on average, hybrid watermilfoil grows faster, branches more, and is less responsive to standard control measures developed for Eurasian watermilfoil. These laboratory results predict less effective control of hybrid watermilfoil in mixed populations treated uniformly with one of these control measures. However, to date there …

The Evolutionary Selective Pressures Exerted On A3 Actinobacteriophages, Cheyenne Weeks-Galindo

Masters Theses, 2010-2019

This study identified evolutionary selective pressures within subcluster A3 actinobacteriophages. These phages are able to infect the clinically important genus Mycobacterium. Understanding the selective pressures on genes in these phage genomes is a step toward understanding the adaptations that result from short-term and long-term associations of phages and bacteria that have been co-evolving for perhaps billions of years. In this study 149 phamilies (phage protein families) of homologous gene sequences were analyzed using Datamonkey. Complete data were obtained for 57 phamilies. Of these, eleven phamilies were affected by recombination, three showed evidence of predominantly diversifying selection, and twenty-four have …

Prioritizing The Management Of Arundo Donax: Recommendations For Removal And Revegetation In California Riparian Habitats, Matthew S. Waterworth

Master's Projects and Capstones

The highly invasive grass species, giant reed (Arundo donax), has been a major contributor to riparian habitat degradation in California for over 50 years. Several modes of vegetative reproduction have allowed this alien species to take advantage of fluvial processes and rapidly spread within California watersheds. A. donax dramatically alters hydrologic regimes, displaces native vegetation, and removes food and habitat for native wildlife. It is widely accepted that removal of this invasive on a watershed scale is critical to restore natural riparian processes and facilitate the reestablishment of native flora and fauna. The following study analyzed the efficacy of …

Population Density Of The Florida Scrub Lizard (Sceloporus Woodi) In Managed Sand Pine Scrub And Longleaf Pine Sandhill Habitats, Matthew D. Kaunert, Lance D. Mcbrayer

Biology: Faculty Publications

Studies investigating managed landscapes are of increasing importance, as fragmentation is a known cause of biodiversity loss. From June to September 2012, we sampled populations of the rare, endemic Florida Scrub Lizard (Sceloporus woodi) across the Ocala National Forest (ONF) to compare lizard density across two managed habitat types. Florida Scrub habitat in the ONF is clearcut and roller-chopped, whereas Longleaf Pine habitat is managed via prescribed burning. We sampled 10 stands of Florida Scrub (2–3 y post disturbance) and 10 stands of Longleaf Pine (1 y post-disturbance) for lizards. We compared lizard density between the interior of …

Oxidative Stress In Avian Embyros, Toshi Tsunekage

Dissertations

Oxidative stress has been implicated in mediating trade-offs in the evolution of life histories. Oxidative stress results from an imbalance in the production of free radicals and an organism’s antioxidant defenses. Higher metabolic rates associated with more rapid growth and shorter development periods may increase oxidative stress and accumulated cellular damage in embryonic tissues. In my dissertation I explored oxidative stress and antioxidant defenses in avian embryos. I measured levels of oxidative stress in tissues of different stage embryos of Japanese quail (Coturnix japonica), and tested if patterns of lipid peroxidation could be explained by changes in the developing embryo’s …

Connectivity Of Coastal And Oceanic Ecosystems: Pelagic Habitat Use By Juvenile Reef Fishes In The Gulf Of Mexico, Katie Bowen

HCNSO Student Theses and Dissertations

The assemblage structure, abundance, biomass, and vertical distribution of juvenile reef fishes in the offshore pelagic habitat of the northern Gulf of Mexico are described as part of the NOAA-supported Offshore Nekton Sampling and Analysis Program. The results presented here are from a 3-month, continuous sampling series in 2011 in which discrete depth strata from 0 to 1500 m were sampled using a 10-m² MOCNESS midwater trawl. This is the first study to examine pelagic juvenile reef fish distributions across the entire oceanic northern Gulf of Mexico seaward of the continental shelf break after the Deepwater Horizon Oil Spill. …

Spatial And Dietary Overlap Creates Potential For Competition Between Red Snapper (Lutjanus Campechanus) And Vermilion Snapper (Rhomboplites Aurorubens), William T. Davis, J. Marcus Drymon, Sean P. Powers

University Faculty and Staff Publications

Understanding the complex nature of direct and indirect species interactions is a critical precursor to successful resource management. In the northern Gulf of Mexico fisheries ecosystem, red snapper (Lutjanus campechanus) and vermilion snapper (Rhomboplites aurorubens) are two commercially harvested species within a larger reef fish complex. These two species share similar habitats and diets; however, little is known about how these species partition habitat and dietary resources. In this study we examined the extent of spatial and dietary overlap between red snapper and vermilion snapper, and experimentally compared their feeding behavior. Field data from multiple gear …

Lead Exposure In Children Through Water And Soil, Sravya Maru

Environmental Management & Risk Assessment (PH 560)

Lead is a metal which has the ability to spread in the earth’s crust and has corrosive property. It is a naturally occurring metal which is soft in nature. Lead exposure in children is through various pathways and the major concentrated sources are the soil and drinking water. Children are most susceptible to lead exposure is due to their growing/developing bodies which are very sensitive to lead. Lead poisoning in children is a preventable environmental disease affecting many children around the world. This paper discusses how soil and water plays a major role in lead exposure to children’s routine life. …

Effects Of Short-Term Soil Conditioning By Cheatgrass And Western Wheatgrass, James J. O'Connor, Janet S. Prevey

The Prairie Naturalist

The exotic grass Bromus tectorum (cheatgrass) is a ubiquitous invader in the western USA. Cheatgrass is a proficient competitor, frequently displacing native plants, forming monotypic stands and reducing biodiversity in ecosystems it invades. Our experiment tested whether short-term soil modification by cheatgrass and a predominant native grass, Pascopyrum smithii (western wheatgrass), affected subsequent growth of both species. We compared productivity of cheatgrass and western wheatgrass by harvesting aboveground biomass of plants grown in either cheatgrass- or western wheatgrass-conditioned soils over two simulated growing seasons. Results indicated that cheatgrass soils do not inhibit the productivity of the native grass, but do …

Remembering Paul B. Kannowski, Robert Seabloom

The Prairie Naturalist

I am saddened to report that Dr. Paul Kannowski passed away 3 September 2015, succumbing to cancer. He was 88. A native of Grand Forks, Paul attended the University of North Dakota for his B.S. and M.S. degrees, and the University of Michigan for his Ph.D. He joined the University of North Dakota Biology Department in 1957, retiring in 1990 after 33 years of service

Paul chaired UND’s Biology Department twice, totaling 13 years, considered to be a remarkable achievement by many of us who have been exposed to that task! His leadership was instrumental in the nearly exponential growth …

The Impact Of Temperature, Ph And Environmental Heterogeneity On Prokaryotic Diversity In Yellowstone National Park Thermal Springs, Xiaoben Jiang

Biology ETDs

Yellowstone National Park (YNP) is one of the largest and most diverse hydrothermal areas on Earth. Extensive culture-independent studies in YNP thermal springs have shown dramatic taxonomic and metabolic diversity in microbial communities. We conducted a survey of bacterial communities along temperature gradients in three alkaline springs with similar geochemistries at the local scale. With these data, we investigated the influence of environmental variables on bacterial community diversity and assemblages along a broad temperature range using high throughput 454 pyrosequencing. Previous studies have suggested that pH is the driver of microbial diversity in thermal springs among geographical regions or at …

Sampling Terrestrial Arthropod Biodiversity: A Case Study In Arkansas, Michael Joseph Skvarla

Graduate Theses and Dissertations

The Interior Highlands is a biodiversity hotspot, with at least 200 known endemic species, but is understudied compared to hotspots, such as the Southern Appalachians. In order to begin to rectify this issue, a nine month study was conducted from mid-March through early December at a 4 ha site at Steel Creek, Buffalo National River, in Newton County, Arkansas. Thirteen collecting methods were employed, including three colors of Lindgren funnel trap, five colors of pan trap, Malaise traps, canopy traps with upper and lower collectors, pitfall traps, and Berlese-Tullgren extraction of leaf litter, which resulted in the collection of 1311 …

Influence Of Habitat And Intrinsic Characteristics On Survival Of Neonatal Pronghorn, Christopher N. Jacques, Jonathan A. Jenks, Troy W. Grovenburg, Robert Wayne Klaver

Natural Resource Management Faculty Publications

Increased understanding of the influence of habitat (e.g., composition, patch size) and intrinsic (e.g., age, birth mass) factors on survival of neonatal pronghorn (Antilocapra americana) is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002–2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans) predation (n = 15) was the …

Prevalence Of Tick-Borne Pathogens In Small Mammals And White-Tailed Deer In Southeast Nebraska, Tim M. Hotaling

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The prevalence of tick-borne diseases has been increasing in the United States for the past couple decades. Studies have been conducted throughout the US identifying tick-borne disease pathogens as well as their hosts and prevalence. Research was conducted in Nebraska to determine the presence of some tick-borne disease pathogens, their vectors, and their hosts, with emphasis made on Borrelia spp., Rickettsia rickettsii, and Ehrlichia chaffeensis.

Small rodents in southeast Nebraska were trapped and sampled at eight study sites using live capture traps. Captured rodents were assessed for active parasitism by ticks which were collected and placed in alcohol. …

Individual-Level Variation And Higher-Level Interpretations Of Space Use In Wide-Ranging Species: An Albatross Case Study Of Sampling Effects, Sarah Gutowsky, Marty Leonard, Melinda Conners, Scott A. Shaffer, Ian Jonsen

Faculty Publications, Biological Sciences

Marine ecologists and managers need to know the spatial extent of at-sea areas most frequented by the groups of wildlife they study or manage. Defining group-specific ranges and distributions (i.e., space use at the level of species, population, age-class, etc.) can help to identify the source or severity of common or distinct threats among different at-risk groups. In biologging studies, this is accomplished by estimating the space use of a group based on a sample of tracked individuals. A major assumption of these studies is consistency in individual movements among members of a group. The implications of scaling up individual-level …

Population Genetics And Epigenetics Of Two Salt Marsh Plant Species Along An Environmental Gradient, Christy M. Foust

USF Tampa Graduate Theses and Dissertations

Phenotypic plasticity is the ability of a given genotype to exhibit different phenotypes in response to environmental variables, which can impact population level processes. Plasticity of ecologically-relevant traits is important to an organism’s environmental response; however, the underlying mechanisms of plasticity are largely unknown. Ecological epigenetics may offer mechanisms (e.g. DNA methylation) underlying phenotypic plasticity. Epigenetics can be defined as the underlying molecular mechanisms that allow one genotype to exhibit different phenotypes. Differential DNA methylation is one epigenetic mechanism that has been correlated with a number of ecologically-relevant traits; including, differential herbivory in Viola cazorlensis, spinescence in Ilex aquifolium …

Lingnan Gardeners Newsletter (No. 12) = 嶺南彩園通訊 (第12期), Lingnan Gardeners, Kwan Fong Cultural Research And Development Programme, Lingnan University

Lingnan Gardeners Newsletter 嶺南彩園通訊

Winter Begins 立冬

In Situ Studies Of Limestone Dissolution In A Coastal Submarine Spring, Rachel Marie Schweers

USF Tampa Graduate Theses and Dissertations

Limestone dissolution in karst environments is likely due to geochemistry of the water, the actions of microbial communities, and the effect of water flow. We explored the rate of limestone dissolution and will examine here the microbial communities associated with the limestone. A conduit within the brackish cave, Double Keyhole Spring, on the coast of central west Florida was the site of the experiment. PVC pipes (5cm x 16cm) were filled with crushed limestone that was screened to a 1.9cm – 2.54cm size range. There were three treatments (5 replicates each): Control - sealed autoclaved controls with limestone and conduit …

Rna Interference: Potato/Tomato Psyllid, Bactericera Cockerelli, Oral Delivery Of Double-Stranded Rnai Construct, Bijaya Kumar Sharma

Biology Theses

The potato/tomato psyllid, Bactericera cockerelli (Sulc.), is a serious and economically important pest of the potato, tomato and other solanaceous crops. This insect is the putative primary vector of the phytopathogenic bacterium Candidatus Liberibacter solanacearum which causes the Zebra Chip in potato. This disease has caused millions of dollars loss to the potato industry. While traditional management programs have minimized the negative impacts of this disease system, a sustainable alternative to chemical treatment is needed. Management of this pest by downregulation of endogenous mRNA using RNA interference (RNAi) technology is one of the best molecular method available; however, several technical …

Integrating Resource Selection Into Spatial Capture-Recapture Models For Large Carnivores, K. M. Proffitt, Joshua F. Goldberg, Mark Hebblewhite, R. Russell, B. S. Jimenez, H. S. Robinson, K. Pilgrim, M. K. Schwartz

Wildlife Biology Faculty Publications

Wildlife managers need reliable methods to estimate large carnivore densities and population trends; yet large carnivores are elusive, difficult to detect, and occur at low densities making traditional approaches intractable. Recent advances in spatial capture-recapture (SCR) models have provided new approaches for monitoring trends in wildlife abundance and these methods are particularly applicable to large carnivores. We applied SCR models in a Bayesian framework to estimate mountain lion densities in the Bitterroot Mountains of west central Montana. We incorporate an existing resource selection function (RSF) as a density co-variate to account for heterogeneity in habitat use across the study area …

Thermal Patterns Constrain Diurnal Behavior Of A Ground-Dwelling Bird, J. Matthew Carroll, Craig A. Davis, R. Dwayne Elmore, Samuel D. Fuhlendorf, Eric T. Thacker

Wildland Resources Faculty Publications

Recently, gaining knowledge about thermal refuges for vulnerable species has been a major focal point of ecological studies, and this focus has been heightened by predicted temperature increases associated with global climate change. To better understand how organisms respond to thermal landscapes and extremes, we investigated the thermal ecology of a gallinaceous bird species (northern bobwhite; Colinus virginianus, hereafter bobwhite) during a key life history period. Specifically, our study focused on the brood-rearing period of precocial bobwhite chicks associated with brood-attending adults. We measured site-specific black bulb temperatures (Tbb) and vegetation characteristics across 38 brood tracking days and 68 random …

On Flavonoid Accumulation In Different Plant Parts: Variation Patterns Among Individuals And Populations In The Shore Campion (Silene Littorea), José C. Del Valle, Mª Luisa Buide, Inés Casimiro-Soriguer, Justen B. Whittall, Eduardo Narbona

Biology

The presence of anthocyanins in flowers and fruits is frequently attributed to attracting pollinators and dispersers. In vegetative organs, anthocyanins and other non-pigmented flavonoids such as flavones and flavonols may serve protective functions against UV radiation, cold, heat, drought, salinity, pathogens, and herbivores; thus, these compounds are usually produced as a plastic response to such stressors. Although, the independent accumulation of anthocyanins in reproductive and vegetative tissues is commonly postulated due to differential regulation, the accumulation of flavonoids within and among populations has never been thoroughly compared. Here, we investigated the shore campion (Silene littorea, Caryophyllaceae) which exhibits …

Species Diversity, Distribution And Seasonal Abundance In Mangrove Associated Molluscs Along The Karachi Coast, Pakistan, Zia Ullah, Itrat Zehra, Muhammad Asif Gondal

Journal of Bioresource Management

Mangrove or Mangal vegetation are typical wetland ecosystems found in coastal deposits of mud and silt throughout the tropics and some distance into the sub-tropical latitude. Species diversity, distribution, seasonal abundance in population and behavioral responses of mangrove associated molluscs (gastropods and bivalves) were investigated in two mangal areas: Sandspit and Korangi, along the Karachi coast of Pakistan. For sampling, a fixed route was followed throughout the study period and the samples were collected and observations were made from HTZ to LTZ. Fourteen species of molluscs (5 Prosobranchia; 6 Pulmonata; 1 Opisthobranchia and 2 Lamellibranchia) belonging to ten families were …

Biodiversity And Ecological Dynamics Of Sciophilous Benthic Communities On Artificial Plates: Emphasis On Reef Sponges, Caidra Elizabeth Hassanzada

HCNSO Student Theses and Dissertations

Low light intensity habitats harbor unique sciophilous benthic communities and are a source of novel and unique sponge fauna. However, the community structure of these habitats is poorly studied to date. Thus, this study attempts to understand the composition and structure of sciophilous sponge populations in southeast Florida. Fifty limestone plates were placed on a shallow reef in Fort Lauderdale for two years (2010-2012). To identify the sponge community and their patterns over time, all plates were photographed at the end of each year. Then, samples were taken from each of the live sponge specimens observed on the plates and …

Switchgrass Germplasm Resources, Michael D. Casler, Kenneth P. Vogel, Melanie Harrison

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. The purpose of this review is to describe the biological and geographical basis for switchgrass germplasm diversity and to provide a resource for scientists and outreach personnel to find switchgrass germplasm to meet their needs. Upland and lowland ecotypes represent the most important polymorphism in switchgrass, with distinct but overlapping geographic distributions. Variation in ploidy exists within both ecotypes, with 2n = 4x = 36 the dominant ploidy …

Forest Diversity And Disturbance: Changing Influences And The Future Of Virginia’S Forests, Christine J. Small, James L. Chamberlain

Virginia Journal of Science

The Virginia landscape supports a remarkable diversity of forests, from maritime dune woodlands, swamp forests, and pine savannas of the Atlantic Coastal Plain, to post-agricultural pine-hardwood forests of the Piedmont, to mixed oak, mesophytic, northern hardwood, and high elevation spruce-fir forests across three mountain provinces in western parts of the state. Virginia’s forests also have been profoundly shaped by disturbance. Chestnut blight, hemlock woolly adelgid, emerald ash borer, and other pests have caused declines or functional extirpation of foundation species. Invasive plants like multiflora rose, Oriental bittersweet, and Japanese stiltgrass threaten both disturbed and intact forests. Oaks and other fire-dependent …

The Contribution Of Syntrophic Fatty-Acid Degrading Microbial Communities To Anaerobic Digester Function And Stability, Prince Peter Mathai

Dissertations (1934 -)

Anaerobic digestion (AD), the conversion of complex organic matter to methane, occurs through a series of reactions mediated by different guilds of microorganisms. AD process imbalances, such as organic overload or high organic loading rates (OLR), can result in the accumulation of volatile fatty acids (VFA) e.g., propionate, which must be degraded to maintain stable reactor function. VFAs are metabolized by syntrophic fatty-acid degrading bacteria (SFAB) in association with methanogenic archaea (collectively, syntrophic microbial communities, SMC). Despite their indispensable role in AD, little is known about the ecology of SFAB, especially under stressed conditions. To facilitate ecological studies, four quantitative …

Evolutionary And Ecological Characterization Of Mayaro Virus Strains Isolated During An Outbreak, Venezuela, 2010, Albert J. Auguste, Jonathan Liria, Naomi L. Forrester, Dileyvic Giambalvo, Moncada Maria, Kanya C. Long, Dulce Morón, Nuris De Manzione, Robert B. Tesh, Eric S. Halsey, Tadeusz J. Kochel, Rosa Hernandez, Juan-Carlos Navarro, Scott C. Weaver

Faculty Publications

In 2010, an outbreak of febrile illness with arthralgic manifestations was detected at La Estación village, Portuguesa State, Venezuela. The etiologic agent was determined to be Mayaro virus (MAYV), a reemerging South American alphavirus. A total of 77 cases was reported and 19 were confirmed as seropositive. MAYV was isolated from acute-phase serum samples from 6 symptomatic patients. We sequenced 27 complete genomes representing the full spectrum of MAYV genetic diversity, which facilitated detection of a new genotype, designated N. Phylogenetic analysis of genomic sequences indicated that etiologic strains from Venezuela belong to genotype D. Results indicate that MAYV is …