Digital Commons Network^™

Novel Lineages Of Prochlorococcus And Synechococcus In The Global Oceans, Sijun Huang, Steven W. Wilhelm, H. Rodger Harvey, Karen Taylor, Nianzhi Jiao, Feng Chen

OES Faculty Publications

Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and …

Diversity, Distribution, And Expression Of Diazotroph Nifh Genes In Oxygen-Deficient Waters Of The Arabian Sea, Amal Jayakumar, Mamoon M. D. Al-Rshadat, Bess B. Ward, Margaret R. Mulholland

OES Faculty Publications

The Arabian Sea oxygen minimum zone (OMZ), the largest suboxic region in the world's oceans, is responsible for up to half of the global mesopelagic fixed nitrogen ( N ) loss from the ocean via denitrification and anammox. Dinitrogen (N₂) fixation is usually attributed to cyanobacteria in the surface ocean. Model prediction and physiological inhibition of N₂ fixation by oxygen, however, suggest that N₂ fixation should be enhanced near the oxygen-deficient zone (ODZ) of the Arabian Sea. N₂ fixation and cyanobacterial nifH genes (the gene encoding dinitrogenase reductase) have been reported in surface waters overlying …

Development Of High-Yielding Sweetgum Plantation Systems For Bioenergy Production In The Southeastern United States, Donald J. Kaczmarek, Brian C. Wachelka, Jeff Wright, Victor C. Steel, Doug P. Aubrey, David R. Coyle, Mark D. Coleman

Biology: Faculty Presentations

No abstract provided.

Recent Changes In The Growth And Nutrient Limitation Of Benthic And Pelagic Algae In Arctic Tundra Ponds, Christina Hernandez

Open Access Theses & Dissertations

Arctic ponds are a dominant feature in Barrow, Alaska. Ponds may function as carbon sinks during the growing season from production of photosynthetic organisms like algae; however, little work has been done on this topic. Environmental changes have been occurring in the Arctic stemming from climate change and human perturbations. The focus of this study was to assess a historically studied region for changes in algal primary production that may have been produced due to increases in temperature over the past 40 years and increased human development. Additionally, this study aimed to determine nutrient limitation of algal production in the …

Implications Of Decade Time Scale Arctic Plant Community Change On Ecosystem Function, Mark Jason Lara

Open Access Theses & Dissertations

Almost half the global soil organic carbon pool is found in northern high latitudes. The majority of this soil carbon is stored in a greenhouse inert state within permafrost. As pronounced warming of high northern latitudes ensues, there is a strong likelihood that this substantial soil organic carbon pool will be mobilized to the atmosphere where it is likely to positively enhance greenhouse warming. Modeling studies suggest this positive feedback could alter future climate states of the Arctic and the globe, and affect how humans may need to adapt to climate change. Accordingly, understanding the patterns and controls and the …

Recipes Of Resolve: Food And Meaning In Post-Diluvian New Orleans, Jessica Claire Menck

Antioch University Dissertations & Theses

In 2005 the city of New Orleans experienced catastrophic flooding as a result of the failure of the federal levee system following Hurricane Katrina. This was an immediate disaster that evolved into a longer-term crisis as the city, state, and national government struggled to respond to the event. This study focuses on one part of managing crisis: meaning making. Specifically, the study investigates meaning making within the food community of New Orleans, asking the questions: is food a way for individuals and groups to make meaning following critical change events such as the failure of the federal levee system in …

Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo

Open Access Theses & Dissertations

Leptopelis, a genus of Central African treefrogs, includes 51 species that live in tropical forests and savannas. Currently, only two species of Leptopelis are known from the poorly explored Itombwe Plateau in eastern Democratic Republic of the Congo (DRC). Itombwe is renowned among conservationists for its rich and endemic amphibian fauna, including: Xenopus itombwensis, Chrysobatrachus cupreonitens, Laurentophryne parkeri, Hyperolius leleupi and at least three species of Arthroleptis. Evolutionary relationships of Itombwe Leptopelis were examined by sequencing two mitochondrial genes (16S: 557 bp [base pairs], cyt b: 620 bp) and one nuclear gene (RAG1: 761 bp). Results recovered strong support for …

The Impact Of Decadal Land Cover Change On The Global Warming Potential Of Beringian Arctic Tundra, David Hwei-Len Lin

Open Access Theses & Dissertations

Arctic terrestrial ecosystems play an important role in the global carbon cycle. If arctic warming continues to rise as projected, large amounts of soil carbon stored in these ecosystems could be released to the atmosphere as carbon dioxide or methane and positively enhance greenhouse warming. Thus, improving understanding of the likely future state and fate of arctic soil carbon, and the carbon uptake potential of arctic terrestrial ecosystems are well recognized research priorities.

At the pan-arctic scale, decadal increases in NDVI (Normalized Difference Vegetation Index), an index of vegetation productivity, have been observed from satellite imagery, indicating a general greening …

Spatial Ecology Of The Trans-Pecos Rat Snake (Bogertophis Subocularis) In The Chihuahuan Desert Of Trans-Pecos Texas, Arturo Rocha

Open Access Theses & Dissertations

The Trans-Pecos Rat Snake (Bogertophis subocularis) is a medium to large rat snake that occurs from south-central New Mexico, south-central Texas, down into the north-central and northeastern states of Mexico. There is paucity in the ecology of B. subocularis to date. Some North American colubrid snakes, such as Thamnophis sirtalis, are the most represented species in thermal ecology and life history studies in all reptiles. There is nothing known on the winter ecological aspects of this species, and very little information regarding its overall ecology. The goal of this study is to determine home range, movement patterns, habitats and utilization …

An Assessment Of Land Cover Change At The Indio Mountains Research Station, Rebecca Anne Escamilla

Open Access Theses & Dissertations

Land cover change is a significant contributor to environmental change on a global scale. In the arid regions of the southwest US, shrub encroachment is one of the most important forms of land cover change. Many factors contribute to shrub encroachment, which can impact structure and function. In the Chihuahuan Desert, mountain ecosystems are known as biodiversity hotspots and are especially susceptible to environmental change making them useful indicators of global change. The overarching goal of this dissertation is to improve i) understanding of land cover change in a Chihuahuan Desert mountain landscape, and ii) how knowledge of land cover …

What Is The Role Of Isolation And Disturbance On The Diversity Of Aquatic Invertebrates In Former Ranchlands Of The Northern Chihuahuan Desert?, Gena Esposito

Open Access Theses & Dissertations

The Chihuahuan Desert is considered one of the most diverse deserts in the world and its aquatic systems have been identified as unique and of global importance. Despite this, the Chihuahuan Desert has remained relatively unstudied, especially concerning its aquatic systems and how the extreme desert environment has shaped the diversity of the organisms within them. In this study we examined the effects of isolation and disturbance on macroinvertebrate diversity in both temporary and permanent desert ponds. To examine the effects of isolation and desiccation, macroinvertebrates were collected from a permanent spring (Squaw Spring) and six nearby temporary ponds (tanks) …

A New Species Of Frog (Strabomantidae: Pristimantis) From Peru With Comments On Its Ectoparasites (Acari: Trombiculidae), Alan W. Brus

Honors Projects

In South America, frogs of the genus Pristimantis are diverse and can be found from lowland forests to elevations of about 4000 m in the Andes. The 444 known species of Pristimantis belong to 16 species groups. One of these groups is the Pristimantis orestes Group, the 14 members of which inhabit the páramo, puna, and upper montane forests in southern Ecuador (3 species) and Peru (11 species). Species of the Pristimantis orestes Group are characterized by having snout-vent lengths ranging from 18.0 to 29.4 mm, short robust bodies, relatively short snouts, narrow digital discs, and areolate ventral skin. Some …

Swamp : Walking The Wetlands Of The Swan Coastal Plain ; And With The Exegesis, A Walk In The Anthropocene: Homesickness And The Walker-Writer, Anandashila Saraswati

Theses: Doctorates and Masters

This project is comprised of a creative work and accompanying exegesis. The creative work is a collection of poetry which examines the history and ecology of the wetlands and river systems of the Swan Coastal Plain, and which utilises the practice of walking as a research methodology. For the creative practitioner walking reintroduces the body as a fundamental definer of experience, placing the investigation centrally in the corporeal self, using the physical senses as investigative tools of enquiry. As Rebecca Solnit comments in her history of walking, ‘exploring the world is one of the best ways of exploring the mind, …

The Impact Of Black Swan (Cygnus Atratus) Grazing On The Seagrass Halophila Ovalis In The Lower Swan River Estuary, Gary Choney

Theses: Doctorates and Masters

Grazing is an important ecosystem process, influencing community structure and rates of ecosystem processes. Although grazing on seagrasses is generally considered to be minor in many temperate regions of the world, waterfowl are often considered significant grazers in temperate lagoons and estuaries. This study examined spatial and temporal variation in swan abundance, grazing pressure and the impact grazing has on seagrass. Little is known on how grazing rates vary on larger water bodies in the southern hemisphere at different times of year and whether temporal changes in grazing rates affect the ability of seagrasses to tolerate grazing. The plant response …

Seeing Through Others' Eyes : Towards A Hybrid Ecology Of Marine Turtle And Dugong In Australia, Zoe Car

Theses: Doctorates and Masters

This thesis explores the conflict between conservationists and Indigenous communities over the hunting of marine turtles and dugong in Australia, with a view to finding a way to overcome the barriers that prevent the resolution of this issue. I approached this exploration as an ecologist, using the framework of Berkes (2004) who proposed three shifts for the field of ecology. This meant taking a systems approach and investigating the intertwining threads of the issue as possible, with a specific focus on integrating the human aspects of the problem in a participatory manner. By doing so my work entered into a …

Grazing On Synechococcus Spp. By The Red-Tide Dinoflagellate Karenia Brevis: Implications For Bloom Dynamics In The Gulf Of Mexico, Leo A. Procise

OES Theses and Dissertations

Karenia brevis, the toxic dinoflagellate responsible for massive red tides in the Gulf of Mexico (GOM), causes fish kills, shellfish poisoning, and acute respiratory irritation in humans. Bloom initiation and maintenance have been linked to the physical environment as well as various nutrient input mechanisms. To date, efforts to quantify nitrogen (N) sources fueling K. brevis blooms in the GOM have not included mixotrophic grazing although many dinoflagellates, including K. brevis, are known to be capable of mixotrophy. This dissertation reports field and laboratory results demonstrating that natural bloom populations and K. brevisisolates from the West Florida …

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending December 31, 2011, Margaret N. Rees

Limnological Studies

Project 1

• Technical assistance with the implementation of the Interagency Monitoring Action Plan (IMAP) for Quagga Mussels is ongoing; remaining analyses are underway with report delivery rescheduled for 05/2012.
• Data have been delivered for Veliger abundance and settlement at different depths of Lake Mead with report delivery re-scheduled for 05/2012.
• Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay
• The Interagency Quagga Mussel Meeting was held on 11/17/2011; the next meeting is scheduled for 02/16/2011.

Project 2

• Appendix 7, an addition to the Long-term Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead and Mohave, has …

Anthropogenic Disturbance On The Vegetation In Makurunge Woodland, Bagamoyo District, Tanzania, C. Mligo, C. Mligo

Tanzania Journal of Science

Makurunge woodland is part of the major vegetation component covering coastal forest landscape in Tanzania that has been severely affected by anthropogenic disturbance. The present study determined the effects of anthropogenic disturbance on biomass, diversity, plant communities and plant species distribution pattern using nested sample plots systematically established along transects. Six major vegetation communities with different biomass were found. Plant species diversity ranged from 2.5 to 3.3 and was high in scrub forests, riverine and thicketed habitats, although the difference among these habitats was not significant (P>0.05). About 61-90% of the woodland was affected and this influenced the plant …

Two Epiparasitic Species Of Phoradendron (Viscaceae) From Honduras: One New And For The Other A Range Extension And Host Determination, Delbert Wiens, Clyde L. Calvin

Aliso: A Journal of Systematic and Floristic Botany

A new species of Phoradendron, Ph. mathiasenii, is described, and a range extension and host are given for Ph. tikalense. Both species are from Honduras and grow as epiparasites, i.e., mistletoes parasitizing other mistletoes. The parasitic host for both epiparasitic species of Phoradendron is Psittacanthus angustifolius (Loranthaceae), which in turn is parasitic on the terrestrial host, Pinus oocarpa, a common forest tree in the collection area. Although the two species of Phoradendron parasitize the same parasitic host and co-occur in the area, they are distinct morphologically. Many plants of Ph. mathiasenii were observed at several collection …

Cover Page

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.

A New Variety Of Lomatium Ravenii (Apiaceae) From The Northern Great Basin And Adjacent Owyhee Region, Kimberly M. Carlson, Donald H. Mansfield, James F. Smith

Aliso: A Journal of Systematic and Floristic Botany

Variability in the group of Lomatium species comprising L. nevadense, L. ravenii, and L. foeniculaceum has led to conflicting classification schemes. While some taxonomists have treated L. ravenii as a distinct species made up of all the populations from California, Nevada, Idaho, and Oregon, others considered L. ravenii to be nothing more than a morphological extreme of L. nevadense. We examined morphological and phylogenetic data from across the range of L. ravenii, concluding that variation in the species warrants varietal distinction. Non-metric multidimensional scaling analysis of 29 populations shows two distinct groups—one from the vicinity of …

Rediscovery Of Monotropastrum Sciaphilum (Andres) G.D.Wallace In China After 91 Years, Min Shen, Chang-Qin Zhang, Gary D. Wallace

Aliso: A Journal of Systematic and Floristic Botany

Monotropastrum sciaphilum (Ericaceae), a mycoheterotrophic member of subfamily Monotropoideae, was rediscovered at its type locality in Yunnan Province, China, 91 years after it was first collected. The type locality is the only locality from which it is known. Field observations in 2007–2010 indicated that inflorescences emerge from the soil between late April and early September. The restricted distribution of M. sciaphilum recommends its listing in the IUCN red book.

Index

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.

High Connectivity In The Deepwater Snapper Pristipomoides Filamentosus (Lutjanidae) Across The Indo-Pacific With Isolation Of The Hawaiian Archipelago, Michelle R. Gaither, Shelley A. Jones, Christopher Kelley, Stephen J. Newman, Laurie Sorenson, Brian W. Bowen

Fisheries Research Articles

In the tropical Indo-Pacific, most phylogeographic studies have focused on the shallow-water taxa that inhabit reefs to approximately 30 m depth. Little is known about the large predatory fishes, primarily snappers (subfamily Etelinae) and groupers (subfamily Epinephelinae) that occur at 100–400 m. These long-lived, slow-growing species support fisheries across the Indo-Pacific, yet no comprehensive genetic surveys within this group have been conducted. Here we contribute the first range-wide survey of a deepwater Indo-Pacific snapper, Pristipomoides filamentosus, with special focus on Hawai'i. We applied mtDNA cytochrome b and 11 microsatellite loci to 26 samples (N = 1,222) collected across …

A Case Study In Wetlands Conservation: Identifying Best Management Practices For Landowner Stewardship, Allison M. Bredbenner

Masters Theses, 2010-2019

This research explores wetlands conservation techniques employed by private landowners owning 1,000 or more acres who were recipients of an Environmental Law Institute National Wetlands Award. Study of private landowner stewardship is timely and important because in the United States, 75 percent of all wetlands are under private ownership. Given that wetlands provide a suite of valuable ecosystem services such as water filtration, flood abatement, and carbon storage, their conservation is critical to a healthy environment and productive economy. To accomplish this research, landowner files were processed into a digital archive and sub-categorized for research purposes. Telephone interviews were conducted …

Evolutionary Relationships Among Duiker Antelope (Bovidae: Cephalophinae), Anne Johnston

LSU New Orleans Theses and Dissertations

Duikers are a species rich subfamily of threatened African antelope whose recent origin poses a challenge to the molecular identification of taxa and estimation of their phylogeny. I test the ability of DNA barcodes to identify all taxa within this group. I then use mitochondrial and nuclear genes to estimate a multi-locus species tree and to date divergence times. DNA barcodes are unable to distinguish many sister taxa, calling into question the utility of barcodes for the regulation of duiker trade or in identification of field-collected feces. The multi-locus phylogeny provides support for the relationships among major duiker lineages and …

Habitat Characteristics Affecting Site Occupation In Wintering Henslow’S Sparrows At Mississippi Sandhill Crane National Wildlife Refuge, Mary E. Nicholson

LSU New Orleans Theses and Dissertations

Henslow’s sparrow (Ammodramus henslowii) winters in recently burned sites in pine savannas of the Southeastern United States. Previous studies have suggested that factors such as seed abundance and litter depth are important to wintering Henslow’s sparrows. My study asked how habitat variables including vegetation structure, seed abundance, and arthropod abundance predict Henslow’s sparrow site occupancy at Mississippi Sandhill Crane National Wildlife Refuge. In this study, Henslow’s sparrow more often occupied sites burned one growing season earlier than sites burned two growing seasons earlier, and did not occupy sites burned three or more growing seasons earlier. Data indicated that mass …

Fine-Scale Genetic Structure And Parentage In Urocitellus Beldingi, Marissa R. Lafler

Master's Theses

Urocitellus beldingi (Belding's ground squirrel), previously known as Spermophilus beldingi, is a social, montane rodent that occupies alpine and subalpine meadows in the Sierra Nevadas (Helgen et al. 2009). The Tioga Pass meadow (Mono Co. CA) population has been studied behaviorally and demographically for several decades. Microsatellites were developed for this species and conditions for polymerase chain reaction (PCR) were defined. Nine microsatellite loci amplified adequately and were in Hardy-Weinberg equilibrium, displaying an average heterozygosity of 0.67±0.19. These nine microsatellite loci were analyzed via PCR to elucidate the fine scale genetic structure, offering insight into population health, stochastic events, and …

A New Locality Of Mesobuthus Eupeus Thersites (C. L. Koch, 1839) (Scorpiones: Buthidae) In East Kazakhstan, Alexander A. Fomichev

Euscorpius

A new locality of Mesobuthus eupeus thersites (C. L. Koch, 1839) is reported, found during the fieldtrip to East Kazakhstan, one of the most northern areas where scorpions are found in Asia. Notes on the habitats, map and photographs of specimens are given.

Fine Roots Of Aspen Clones In High Salt And Petroleum Hydrocarbon Pollution, Kim Yrjälä, Ivika Ostonen, Shinjini Mukherjee, Timo Sipila, Lu-Min Vaario, Pertti Pulkkinen

Aspen Bibliography

The quality of polluted soil can much be improved and the environmental risks reduced by use of phytoremediation. Harmful hydrocarbon compounds can be degraded through the activity of plant and its associated microbes. We previously showed that PAHs increase aromatic ring-cleavage gene diversity in rhizosphere of birch (Sipilä et al. 2008, Yrjälä et al. 2010a) and the rhizosphere of aspen harbors Burkholderia bacteria able to degrade aromatics (Yrjälä et al. 2010b). The results are promising for successful remediation of polluted soils with woody plants. The aim of our studies is to elucidate the response of the plant and the associated …