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The Spread Of Exotic Plant Species At Mount St. Helens: The Roles Of A Road, Disturbance Type And Post-Disturbance Management, Lindsey Karr

Environmental Science and Management Professional Master's Project Reports

The landscape of Mount St Helens was dramatically transformed when it erupted on May 18, 1980, creating an outstanding opportunity for ecologists to study succession following a large, intense, natural disturbance. Within the expansive (600 km²) blast area there is varied ownership and a mix of management objectives for the post-eruption landscape. On lands administered by the U.S. Forest Service, there are portions of the blast area that have been designated as a National Volcanic Monument, where the primary management objective is to allow for natural succession to proceed substantially unimpeded. In other areas outside the Monument, salvage …

Plant Response To 14 Engineered Log Jams On The North Fork Toutle River, Wa Sediment Plain, Todd Ashley

Environmental Science and Management Professional Master's Project Reports

I sought to evaluate the vegetative response to the installation of the 14 engineered log jams (ELJs) on the North Fork Toutle River (NFTR) Sediment Plain. The NFTR sediment plain is constantly being reworked due to channel bank erosion caused by a combination of processes including flow erosion and gravitational mass failure. Vegetation has the ability to protect the bank from erosion as well as providing other stabilizing effects. The ELJ structures were designed in part to protect localized areas of the sediment plain and allow vegetated islands to develop. The purpose of these vegetated islands is to trap sand …

Getting Plant Conservation Right (Or Not): The Case Of The United States, Kayri Havens, Andrea T. Kramer, Edward O. Guerrant Jr.

Environmental Science and Management Faculty Publications and Presentations

Effective plant conservation includes addressing basic needs such as information about species distribution and rarity; research, management, education, and training capacity to mitigate threats facing threatened species; policy and funding to support continued capacity and conservation; and, ultimately, a public that understands and supports the importance of plants and the need for their conservation. Coordination of plant conservation efforts is also needed to ensure that resources and expertise are used in a strategic, efficient, and effective manner.We argue that no country is currently getting plant conservation right; plants are becoming increasingly rare around the world. Plants are often not fully …

Sampling For Effective Ex Situ Plant Conservation, Edward O. Guerrant Jr., Kayri Havens, Pati Vitt

Environmental Science and Management Faculty Publications and Presentations

Sampling a whole flora or any significant subset for ex situ conservation purposes is a complex, long-term proposition. Thus, it is important to consider what constitutes an adequate sample not only for all taxa as a whole but also for each taxon individually as well as how to strategically schedule collection over time. There are five basic sampling questions: from which species to collect, from how many and which populations, from how many and which individuals, how many and what kind of propagules to collect, and, finally, at what point is the desired sample size too great for a population …

Small Tidal Channels Improve Foraging Opportunities For Calidris Shorebirds, Aileen K. Miller, Catherine E. De Rivera

Environmental Science and Management Faculty Publications and Presentations

Estuarine intertidal habitats are heterogeneous, therefore migratory shorebirds are expected to forage in microhabitats where they can maximize their energy intake. Identifying proximate factors that migratory shorebirds use to accept or reject a particular habitat patch will help land managers make conservation and restoration decisions that provide the greatest benefits to shorebird populations during migration, a period of intense energy usage. We examined whether small semipermanent tidal channels were preferentially used by foraging Western Sandpipers (Calidris mauri) and Dunlins (C. alpina) during a spring migratory stopover in Bandon Marsh, an Oregon, USA, estuary. Further, we tested …

Winter Climate Change Affects Growing-Season Soil Microbial Biomass And Activity In Northern Hardwood Forests, Jorge Durán, Jennifer L. Morse, Peter M. Groffman, John L. Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany C. Fisk, Mryon J. Mitchell, Pamela H. Templer

Environmental Science and Management Faculty Publications and Presentations

Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher …

Osmb Final Report: Task 3. Containment Strategies For Eurasian Watermilfoil Infested Central Or Lakes, Vanessa Morgan, Mark Sytsma

Center for Lakes and Reservoirs Publications and Presentations

In recent years, public awareness of aquatic invasive species (AIS) has increased considerably in Oregon and elsewhere in the western U.S.. News articles, boat inspection stations and AIS permit programs have drawn attention to the threat of aquatic invasive species, especially animals like zebra mussels (Dreissena polymorpha), quagga mussels (Dreissena bugensis), and New Zealand mudsnails (Potamopyrgus antipodarum). However, invasive aquatic plants are also capable of causing severe impacts and may similarly be transferred between waterbodies on boats, trailers or other equipment. Heavy infestations can hinder recreational use by motorized and non-motorized boats, snag fishing lines, threaten the safety of swimmers …

Occurrence Of Synthetic Amino-Polycarboxylate Chelating Compounds In Oregon Surface Waters, Nathan A. Hersey

Civil and Environmental Engineering Master's Project Reports

Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial settings. When chelating compounds are present, the activity and transport of metal cations in the environment and the uptake of metals in natural systems can be affected. Surface water samples from across the United States were analyzed, as well as local collection and analysis of surface waters and wastewater treatment plant effluent from around Northwest Oregon. Results indicate presence of synthetic chelating compounds in areas with human activity, and absence in …

Analysis Of Soil And Groundwater Microbial Population Dynamics At In Situ Bioremediation Sites In California And Texas, Farrar C. Stewart

LSU Master's Theses

Traditional methods for assessing in situ microbial communities often provide limited information on substrate utilization in bioremediation processes. The goal of this research was to assess new methods for describing the microbial communities found in the groundwater and affected contaminated soils documenting changes in community structure, population dynamics, substrate utilization and biodegradation of constituents of concern (CoC) during a site remediation. Two in situ bioremediation pilot studies using biological plugs are being conducted, one in the California San Francisco Bay Area (Sunnyvale) and one in the East Texas Piney Woods (Longhorn). The hypothesis is that changes in community structure, population …

Genetic Variation, Local Adaptation And Population Structure In North American Red Oak Species, Quercus Rubra L. And Q. Ellipsoidalis E. J. Hill, Jennifer F. Lind-Riehl

Dissertations, Master's Theses and Master's Reports - Open

Forest trees, like oaks, rely on high levels of genetic variation to adapt to varying environmental conditions. Thus, genetic variation and its distribution are important for the long-term survival and adaptability of oak populations. Climate change is projected to lead to increased drought and fire events as well as a northward migration of tree species, including oaks. Additionally, decline in oak regeneration has become increasingly concerning since it may lead to decreased gene flow and increased inbreeding levels. This will in turn lead to lowered levels of genetic diversity, negatively affecting the growth and survival of populations. At the same …

Electrocatalytic Processing Of Renewable Biomass-Derived Compounds For Production Of Chemicals, Fuels And Electricity, Le Xin

Dissertations, Master's Theses and Master's Reports - Open

The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with …

Retiring Professor Leaves Environmental Legacy, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Detecting The Influence Of Best Management Practices On Vegetation Near Ephemeral Streams With Landsat Data, Matthew Rigge, Alexander Smart, Bruce Wylie, Kendall De Van Kamp

Natural Resource Management Faculty Publications

Various best management practices (BMPs) have been implemented on rangelands with the goals of controlling nonpoint sourcepollution, reducing the impact of livestock in ecologically important riparian areas, and improving grazing distribution.Providing off-stream water sources to livestock in pastures, cross-fencing, and rotational grazing are common rangeland BMPsthat have demonstrated success in drawing livestock grazing pressure away from streams. We evaluated the effects of rangelandBMP implementation with six commercial-scale pastures in the northern mixed-grass prairie. Four pastures received a BMPsuite consisting of off-stream water, cross-fencing, and deferred-rotation grazing, and two pastures did not receive BMPs. Wehypothesized that the BMPs increased the quantity …

Environmental Stressors: Pathways Of Exposure And Aquatic Invertebrate Response, Carly Jean Nowicki

Wayne State University Dissertations

The need to monitor freshwater and detect impairments prior to observable impacts is crucial to maintain species diversity and ecosystem function. Therefore, understanding the contribution of various matrices (i.e., sediment and water) to chemical exposure is critical for remediation of impacted sites.

To evaluate various matrices of chemical exposure, I focused on the organic pollutant polychlorinated biphenyls (PCBs) due to their relatively ubiquitous nature, high toxicity, and adverse effects on humans and wildlife. In complementary laboratory and field experiments, I compared the effects of aqueous versus sedimentary exposure of PCBs on invertebrates. In the laboratory, organisms exposed to PCB-contaminated sediments …

Effects Of Including Saponins (Micro-Aid®) On Intake, Rumenfermentation And Digestibility In Steers Fed Low-Qualityprairie Hay, C P. Mcmurphy, A J. Sexten, G L. Mourer, E D. Sharman, S J. Trojan, M J. Rincker, W K. Coblentz, D L. Lalman

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Sixteen ruminally cannulated crossbred steers (529 ± 45 kg initial body weight, BW) wereused to evaluate in situ dry matter (DM), neutral detergent fiber (aNDF), and N degrada-tion characteristics of low-quality prairie hay, blood urea-N (BUN) and rumen fermentationparameters in steers provided a protein supplement with or without Micro-Aid®(MA; plantderived saponin). Steers were allowed ad libitum access to chopped prairie hay (49 g crudeprotein (CP)/kg DM and 738 g aNDF/kg DM) and randomly assigned to one of four treat-ments: (1) no supplement (C), (2) cottonseed meal and wheat middlings: 920 g DM/d (PC;positive control), (3) MA added to PC to …

Predicting Phosphorus Dynamics In Complex Terrains Using A Variable Source Area Hydrology Model, Amy S. Collick, Daniel R. Fuka, Peter J.A. Kleinman, Anthony R. Buda, Jennifer L. Weld, Mike J. White, Tamie L. Veith, Ray B. Bryant, Carl H. Bolster, Zachary M. Easton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Phosphorus (P) loss from agricultural watersheds has long been a critical water quality problem, the control of which has been the focus of considerable research and investment. Preventing P loss depends on accurately representing the hydrological and chemical processes governing P mobilization and transport. The Soil and Water Assessment Tool (SWAT) is a watershed model commonly used to predict run-off and non-point source pollution transport. SWAT simulates run-off employing either the curve number (CN) or the Green and Ampt methods, both assume infiltration-excess run-off, although shallow soils underlain by a restricting layer commonly generate saturation-excess run-off from variable source areas …

History, Nesting Population, Migration, Home Range And Habitats Used By Louisiana Bald Eagles, Nickolas Ryan Smith

LSU Master's Theses

The population of Bald Eagles (Haliaeetus leucocephalus) nesting in Louisiana reached precariously low numbers in the early 1970’s, and although the population has since increased markedly, resident eagles remain a species of conservation concern in Louisiana. Using statewide aerial nest survey data from 1975–2008, I documented the history and quantified the recovery of the nesting population in Louisiana. Known active nests increased exponentially from 7 to 387 during this period, exhibiting a mean annual rate of increase of 11.1 ± 0.3% per year with no indications of slowing. By 1990, the nesting population in Louisiana had exceeded all goals of …

Exploring The Responsibilities Of Wildlife Law Enforcement Officers: An Examination Of Citations Issued By Kentucky Conservation Officers, Conrad Morgan Lanham

Online Theses and Dissertations

Conservation officers are law enforcement agents whose primary responsibility is the enforcement of statutes regarding wildlife. Several bodies of research have noted the expansion of law enforcement capabilities and responsibilities of conservation officers to include the enforcement of general laws that fall outside the conservation officers' original mandate. The purpose of this study is to explore the work roles of contemporary conservation officers in Kentucky. Using data from citations issued by Kentucky conservation officers from 2006 to 2011, this research examines patterns of wildlife violations, boating violations, and general violations across time and space. Comparisons of these types of violations …

Visitor Perceptions Of Black Bear Management Options In Big South Fork National River And Recreation Area, Robert Maxwell Lakes

Online Theses and Dissertations

Human/bear interactions will continue to increase as humans continue to live and recreate in closer proximity to bear habitat. One area positioned for a marked increase in human/bear interactions is Big South Fork National River and Recreation Area (BISO). To make decisions on the best management options for the growing black bear population, BISO managers need information about park visitor beliefs and concerns. The purpose of this research was to examine stakeholder views related to black bear management options within BISO. We hypothesized that different stakeholders would have varying opinions about management actions towards black bears. The findings were that …

Destruction Of Chlorinated Hydrocarbons By Zero-Valent Zinc And Bimetallic Zinc Reductants In Bench-Scale Investigations, Christopher Scott Cushman

Browse all Theses and Dissertations

Many remediation technologies have been developed to treat extensive subsurface contamination by chlorinated hydrocarbons (CHCs). One such technology is a permeable reactive barrier (PRB), which contains reactive media that acts as an electron donor in order to reduce CHCs. Extensive effort has been placed on finding the most suitable reactive media in PRBs, with zero-valent iron (ZVI) being the most commonly utilized media. However, zero-valent zinc (ZVZ) is a promising replacement for ZVI in PRBs as it will more readily donate electrons, resulting in more rapid degradation of CHCs. In addition, amending a secondary/catalytic metal to primary metal surface can …

Biogeochemistry Of Sulfur Isotopes In Crystal Lake, Clark County, West-Central Ohio, Amanda Lynn Meyer

Browse all Theses and Dissertations

Crystal Lake showed distinct biogeochemical patterns, which were governed by thermal stratification, photosynthesis, and sulfur redox processes. Field parameter measurements and water and Planktothrix rubescens samples were collected in May, August, and October, 2013 at the deepest point in the lake, to better understand these processes. At the metalimnion-hypolimnion boundary, P. rubescens produced chlorophyll and turbidity maxima. Photosynthesis produced oxygen-rich and nutrient-poor surface waters. The decay of organic matter produced anoxic, nutrient-rich water in the hypolimnion. Sulfate concentrations were high in the epilimnion and metalimnion, with a maximum at the layer of P. rubescens, and decreased with depth in the …

Mercury Distributions And Cycling In The North Atlantic And Eastern Tropical Pacific Oceans, Katlin L. Bowman

Browse all Theses and Dissertations

The distribution of mercury (Hg) in the ocean is complex as a result of in situ chemical transformations and inputs from natural and anthropogenic sources. Within the ocean, inorganic Hg is methylated to monomethylmercury (MMHg), which bioaccumulates and biomagnifies in marine food webs and poses a health risk to humans who eat fish. The biogeochemistry of Hg in the ocean has been studied for decades, however, recently improved sampling and analytical techniques have allowed for an enhanced understanding of global distributions of different Hg species. This dissertation uses a newly developed method for the analysis of MMHg that improves detection …

Environmental Factors Affecting Methylmercury In Fish Of The Laurentian Great Lakes Region, Joel Harvey

Browse all Theses and Dissertations

Monomethylmercury (MMHg) can accumulate in fish to concentrations that pose a threat to the health of fish, piscivorous organisms, and humans who eat fish. A variety of environmental factors have been hypothesized to influence either the methylation of inorganic Hg or the bioaccumulation and magnification of MMHg. This study investigates the influence of selected environmental factors on MMHg concentrations in freshwater fish across a regional scale, most of the U.S. portion of Laurentian Great Lakes region. Fish MMHg was correlated with proton deposition, sulfate deposition, nitrate deposition, mercury deposition, pH, watershed area, and Secchi depth. Only proton deposition was positively …

Effects Of Toxic Cyanobacteria (Microcystis Aeruginosa) On The Feeding And Reproduction Ecology Of The Copepod Eurytemora Affinis From Green Bay, Lake Michigan, Nicholas J. Barrett

Lawrence University Honors Projects

Toxic Cyanobacteria is known to be a bad food source to consumers as well as a main contributor to harmful algal blooms. This study investigates the feeding relationship between an invasive copepod in the Great Lakes system, Eurytemora affinis, and a toxic strain of cyanobacteria, Microcystis aeruginosa. E.affinis has been shown to feed on toxic cyanobacteria. By measuring the filtering rate, ingestion rate, egg production and offspring size between three different food conditions, we hope to gain insight into the effects of toxic cyanobacteria on the feeding and reproduction of this copepod. Food sources include a good green algal …

Sedimentation And Barnacle Recruitment And Growth In A Shallow Coastal Lagoon Of South Texas, John Jack Gray

Theses and Dissertations - UTB/UTPA

According to the United States Environmental Protection Agency, one of this nation’s greatest concerns to the receiving waters of an aquatic system is the impairment of water quality due to sediment transport. Thus, an aquatic system whose receiving waters are subject to unrestrained sediment transport from a spoil bank, which is an unstabilized depository for sediment acquired during a dredge, should be a concern. In this study an attempt was made to assess sedimentation and its effect on the life cycle of sessile aquatic life over a year. South Bay was chosen for the study site because it is adjacent …

Advances In Understanding The Molecular Composition Of Dissolved Organic Matter And Its Reactivity In The Environment, Rajaa Mesfioui

Chemistry & Biochemistry Theses & Dissertations

Dissolved organic matter (DOM) is the ultimate product of Earth's systems dynamics. DOM chemical signature is strongly shaped by the interaction among Earth's spheres, such as the atmosphere, the geosphere, the biosphere, and the hydrosphere, but also life and human activity. DOM source, composition, photochemical alteration and availability affect freshwater ecosystems, their carbon and nitrogen fluxes and, thus, the global carbon and nitrogen cycles. The aim of this thesis was to gain an understanding of the molecular composition of DOM and its photochemical and biological reactivity in an environment impacted by anthropogenic disturbance. The York and James River systems within …

Phylogenetics, Population Genetics, And Evolution Of The Mallard Complex, Philip Lavretsky

Browse all Theses and Dissertations

Speciation is primarily regarded as an ancestral split that results in two distinct taxonomic units, and proceeds in stages along a continuum from initiation (i.e., population divergence) to completion (i.e., reproductively isolated species). Establishing how and why populations diverge, including the primary mechanisms influencing these events is a major objective for evolutionary scientists. Focusing on incipient forms, researchers attempt to disentangle the antagonistic nature of selection, genetic drift, and gene flow in the speciation process.

In chapter 1, I investigate the phylogenetic relationships of 14 closely related taxa within the mallard complex (Anas spp.) that underwent a radiation within the …

Native Insect Herbivory Limits Population Growth Rate Of A Non-Native Thistle, James O. Eckberg, Brigitte Tenhumberg, Svata M. Louda

Brigitte Tenhumberg Papers

The influence of native fauna on non-native plant population growth, size, and distribution is not well documented. Previous studies have shown that native insects associated with tall thistle (Cirsium altissimum) also feed on the leaves, stems, and flower heads of the Eurasian congener Cirsium vulgare, thus limiting individual plant performance. In this study, we tested the effects of insect herbivores on the population growth rate of C. vulgare. We experimentally initiated invasions by adding seeds at four unoccupied grassland sites in eastern Nebraska, USA, and recorded plant establishment, survival, and reproduction. Cumulative foliage and floral herbivory …

Biogeochemical Aspects Of Uranium Mineralization, Mining, Milling, And Remediation, Kate M. Campbell, Tanya J. Gallegos, Edward R. Landa

United States Geological Survey: Staff Publications

Natural uranium (U) occurs as a mixture of three radioactive isotopes: 238U, 235U, and 234U. Only 235U is fissionable and makes up about 0.7% of natural U, while 238U is overwhelmingly the most abundant at greater than 99% of the total mass of U. Prior to the 1940s, U was predominantly used as a coloring agent, and U-bearing ores were mined mainly for their radium (Ra) and/or vanadium (V) content; the bulk of the U was discarded with the tailings (Finch et al., 1972). Once nuclear fission was discovered, the economic importance of U increased greatly. The mining and milling …

Comparing Cropland Net Primary Production Estimates Frominventory, A Satellite-Based Model, And A Process-Based Model In Themidwest Of The United States, Zengpeng Li, Shuguang Liu, Zhengxi Tan, Normann B. Bliss, Claudia J. Young, Tristram O. West, Stephen M. Ogle

United States Geological Survey: Staff Publications

Accurately quantifying the spatial and temporal variability of net primary production (NPP) for crop-lands is essential to understand regional cropland carbon dynamics. We compared three NPP estimates for croplands in the Midwestern United States: inventory-based estimates using crop yield data from the U.S. Department of Agriculture (USDA) National Agricultural Statistics Service (NASS); estimates from the satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) NPP product; and estimates from the General Ensemble biogeochemical Modeling System (GEMS) process-based model. The three methods estimated mean NPP in the range of 469–687 g C m−2yr−1and total NPP in the range of318–490 Tg C yr−1for croplands in …