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Quantifying Current Soil Brine Contamination Within The Smackover Oil Field In Arkansas Using Multispectral Digital Imagery, Victoria Williams Dec 2023

Quantifying Current Soil Brine Contamination Within The Smackover Oil Field In Arkansas Using Multispectral Digital Imagery, Victoria Williams

Electronic Theses and Dissertations

A remote sensing study was performed to quantify current soil brine contamination across the historic Smackover Oil Field in south-central Arkansas, United States. The oil field was established in 1922 and was not subject to the future waste regulations created by the Arkansas Oil and Gas Commission. Brine is a waste product of oil manufacturing which contains water with high salt levels. The storage and transport of brine in the oil field created landscape scarring across the study area.

Landsat 9 multispectral digital imagery was utilized to create supervised classification maps based on earthen pits and creek scarring across the …


Effectiveness Of 2016 Watershed Protection Plan On Bacteria And Nutrient Concentration Loads In The Attoyac Bayou Watershed, Jack Henson Aug 2023

Effectiveness Of 2016 Watershed Protection Plan On Bacteria And Nutrient Concentration Loads In The Attoyac Bayou Watershed, Jack Henson

Electronic Theses and Dissertations

In 2004, bacteria and nutrient sampling on the Attoyac Bayou Watershed discovered elevated concentrations of E. coli on five of the main channels key tributary streams. The Attoyac Bayou was then listed on the Texas 303d list of impaired waterbodies and further research was conducted to identify the main sources of contamination in the waterbody. In 2016, the Attoyac Bayou Watershed Plan (WPP) was developed to implement best management practices (BMPs) that would decrease bacteria and nutrient concentrations in the watershed. Educational outreach programs, on-site-sewage facility repair, and livestock management were some of the strategies suggested by the protection plan …


Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano May 2023

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …


Distribution And Soil Characteristics Associated With The Neches River Rose-Mallow (Hibiscus Dasycalyx), Morgan E. Langlinais Dec 2022

Distribution And Soil Characteristics Associated With The Neches River Rose-Mallow (Hibiscus Dasycalyx), Morgan E. Langlinais

Electronic Theses and Dissertations

The Neches River rose-mallow, Hibiscus dasycalyx, is a rare herbaceous perennial endemic to East Texas. The threatened, obligate wetland species is currently at risk of being lost in the wild due to habitat loss, encroachment of nonnative and native plant species, and hybridization with two other Hibiscus congeners, Hibiscus laevis and Hibiscus moscheutos. Known locations of each of the three Hibiscus species were used to measure select soil characteristics and habitat variables associated with each of the rose-mallows. H. dasycalyx was concluded to be associated with more fertile soils and slightly more canopy coverage than H. laevis and …


Effects Of Excessive Soil Phosphorus Accumulation On Loblolly Pine (Pinus Taeda L.) Seedlings, Hannah C. Bays Aug 2022

Effects Of Excessive Soil Phosphorus Accumulation On Loblolly Pine (Pinus Taeda L.) Seedlings, Hannah C. Bays

Electronic Theses and Dissertations

Many landowners in East Texas apply poultry litter to pastures as a source of nitrogen (N) for forage crops. After many years of repeated poultry litter application, soils can accumulate extremely high extractable phosphorus (P) concentrations, sometimes over 1000 mg kg-1 of plant available P. Landowners report the conversion of these pastures to loblolly pine (Pinus taeda L.) plantations is often problematic, with poor seedling survival and abnormal tree growth. This study was conducted to assess the effects of excessive soil phosphorus on loblolly pine seedlings. An outdoor pot study was conducted using bare root seedlings and triple …


Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall Aug 2021

Development Of Standard Operating Procedure With Modified Method To Quantify Benzene And Other Volatile Organic Compounds In Air Samples Using Gas Chromatography, Heather Hall

Electronic Theses and Dissertations

Stephen F. Austin State University (SFASU) Department of Environmental Science has recently invested in a gas chromatograph which can be used to analyze air samples for volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylenes (BTEX). The goal of this project was to develop a standard operating procedure (SOP) and modify the current method for the detection of VOCs associated with oil and gas drilling activity to accommodate the equipment and capabilities of SFASU Environmental Assessment Lab. This study aims to provide the framework for future research in air quality monitoring in the Eagle Ford Shale area. An …


The Effects Of Prescribed Burning On Soil Water Infiltration Rates And Other Select Soil Physical And Chemical Properties In East Texas, Cassady Pennington Dunson, Brian P. Oswald, Kenneth Farrish, Tyson Hart Aug 2021

The Effects Of Prescribed Burning On Soil Water Infiltration Rates And Other Select Soil Physical And Chemical Properties In East Texas, Cassady Pennington Dunson, Brian P. Oswald, Kenneth Farrish, Tyson Hart

Electronic Theses and Dissertations

This study focused on whether prescribed burning affects soil physical and chemical properties, especially water infiltration, in Western Gulf Coast forests. Soil water infiltration rates were measured 1) pre-burn (before the fire), 2) post-burn (one month after the fire), and 3) at vegetation green-up (three months after the fire). Soil samples were also collected to determine the effects of prescribed burning on soil pH, bulk density, particle density, pore space, soil strength, O-horizon weight and depth (organic matter), water stable aggregates, and soil fertility. This project was conducted on two different burn intervals. The National Forests and Grasslands of Texas …


Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Chris M. Schalk, Daniel Unger, David Kulhavy Dec 2020

Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Chris M. Schalk, Daniel Unger, David Kulhavy

Electronic Theses and Dissertations

The Arizona toad (Anaxyrus microscaphus) and Jones’ waxy dogbane (Cycladenia humilis var. jonesii) are habitat specialists with historical ranges in the desert southwest and specifically, Zion National Park (ZION). The machine learning method, MaxEnt, constructed species distribution models (SDMs) in ZION for the two study species at 30 m and 900 m spatial resolutions using climate, topographic, and remotely sensed data. Additionally, 900 m forecasting models were constructed to observe the shifts in suitable habitat for the years 2050 and 2070, based off two representative concentration pathway scenarios. Results indicate promising predictive power for both high …


Tree Canopy Effects On Roof-Harvested Rainwater In East Texas, Kimberly Gamez Dec 2020

Tree Canopy Effects On Roof-Harvested Rainwater In East Texas, Kimberly Gamez

Electronic Theses and Dissertations

Nine experimental metal roofs with rainwater harvesting systems were constructed and water quality parameters were measured in 2016-2017 in order to evaluate the effects of arboreal overhang on roof-harvested rainwater quality collected in East Texas. Three treatments were evaluated: Rainwater collected from roofs without any overhanging tree vegetation, rainwater collected from roofs under predominantly Southern yellow pine tree cover, and rainwater collected from roofs under predominantly hardwood tree cover. Rainwater was collected from these roofs for one year. The effects of canopy cover on water quality parameters, comparison to drinking water standards, first-flush efficiency, and seasonal effects were evaluated.

Significant …


Aerial Mineral And Organic Particulate Deposition In East Texas, Sarah Caton, Sarah Caton Dec 2020

Aerial Mineral And Organic Particulate Deposition In East Texas, Sarah Caton, Sarah Caton

Electronic Theses and Dissertations

This study determined the monthly amount, particle size distribution, and chemical composition of particulate deposition in East Texas over a one-year period. It also recognized the seasonal patterns of this deposition as well as its primary origins as either mineral or organic particulate deposition.

The study recorded the monthly mass of deposition, particle size distribution, and the chemical makeup of deposition throughout a period of twelve months at seven sampling locations. SEM-EDS technology was used in conjunction with PCI programming to measure the sizes of depositional particles throughout this time period and identify their chemical composition.

The total yearly deposition …


The Persistence Of Acid Mine Drainage At An East Texas Coal Mine, Sarah Zagurski Dec 2020

The Persistence Of Acid Mine Drainage At An East Texas Coal Mine, Sarah Zagurski

Electronic Theses and Dissertations

The objective of this study was to estimate the time it will take for acid forming materials (pyrite) to be weathered to a state of equilibrium and thus cease to produce acid in ground and surface waters within Oak Hill Mine. This was accomplished using an ex-situ kinetic leaching study incorporating a humidity cell in a controlled laboratory setting. Leaching was conducted on soil cores obtained from the vadose zone at Oak Hill Mine and the humidity cell was used to accelerate oxidation of the pyrite within the cores.

An in-situ field study was also conducted that monitored groundwater conditions …


The Influence Of Environmental Variables On The Height Growth Of Loblolly Pine (Pinus Taeda) In The Western Gulf, Osakpamwan Edo-Iyasere Aug 2020

The Influence Of Environmental Variables On The Height Growth Of Loblolly Pine (Pinus Taeda) In The Western Gulf, Osakpamwan Edo-Iyasere

Electronic Theses and Dissertations

Understanding the effects of environmental factors on stand growth is important in optimizing forest management plans. This study investigated the effects of soil and climate factors on the height growth (site index) of loblolly pine (Pinus Taeda L.) using data collected from permanent plots established in intensively-managed plantations across East Texas and Western Louisiana. The Chapman-Richards model was selected as the base model to describe the height-age relationships and important soil and climate variables were incorporated into the models as model parameter coefficient adjustors. Our results showed that the most important factors for predicting site index were nitrogen …


Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan Aug 2020

Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan

Electronic Theses and Dissertations

In September 2008, Hurricane Ike swept through the Gulf of Mexico striking the Gulf Coast, claiming hundreds of lives and causing billions of dollars in damage. The hurricane left behind elevated sea salt concentrations in the soil and groundwater, preventing the unaided return of live oaks and other species to the island. To determine effective ways to ameliorate the elevated Na+ concentrations in the soil, eight treatments were applied to the soil and combinations of three species of plants, live oak (Quercus virginiana), hybrid bald cypress (TaxodiumT406’), and yellow hibiscus (Hibiscus hamabo …


Land Suitability Analysis For Windfarm Development In Texas, Robert Laszlo Milecz Aug 2020

Land Suitability Analysis For Windfarm Development In Texas, Robert Laszlo Milecz

Electronic Theses and Dissertations

Due to the negative impact on the environment of conventional electric power generation methods, especially coal and oil-fired generating plants, wind power as an alternative for sustainable energy has received more attention in recent years. The purpose of this project was to apply Geographic Information System (GIS), integrated with Multi Criteria Decision Making (MCDM), for identifying suitable areas for wind turbine applications in Texas. Factors taken into consideration included socioeconomic criteria such as distance to highways, proximity to airports and urban areas, localized environmental criteria such as terrain slope and distance to rivers, affected waterbodies, and wildlife management areas. Also …


Chemostratigraphy Of Carbonate Gravity Flows Of The Wolfcamp Formation In Crockett County, Midland Basin, Texas, Alex Blizzard, Julie Bloxson Jun 2020

Chemostratigraphy Of Carbonate Gravity Flows Of The Wolfcamp Formation In Crockett County, Midland Basin, Texas, Alex Blizzard, Julie Bloxson

Electronic Theses and Dissertations

Sediment gravity flows into deep-water environments are important stratigraphic traps in lithologically diverse reservoirs generating multiple plays for hydrocarbon exploration. These highly heterogeneous deposits can be studied by utilizing chemostratigraphy and higher-order sequence stratigraphy; being an accurate method for reservoir characterization. Studying these gravity flows along a carbonate platform’s slope can further expand an understanding of the stratigraphy that is filling adjacent basins. The application of elemental analyses can support in identifying mineralogy that impact reservoir quality, especially when conventional testing cannot be applied.

This study utilizes five cores containing the Wolfcamp Formation from the southeastern slope of the Central …


Simulated Mine Land Reclamation Impact On Biomass Partitioning And Nutrient Contents In Loblolly Pine, Osarumen Egharevba May 2020

Simulated Mine Land Reclamation Impact On Biomass Partitioning And Nutrient Contents In Loblolly Pine, Osarumen Egharevba

Electronic Theses and Dissertations

Forest productivity on reclaimed mine land is hindered by soil compaction. Different techniques have been used to alleviate the effect of compaction to various degrees of success. The Forestry Reclamation Approach (FRA) was developed in the Appalachians and has been used to improve forest productivity on reclaimed mines in this region. The FRA provides a step by step method designed to reduce compaction, control erosion, provide land stabilization and accelerate forest succession. This method had not been evaluated in the Gulf Coastal Plain, where the pan scraper reclamation method is commonly used. However, using pan scrapers increases mine soil compaction …


Applications Of Digital Remote Sensing To Quantify Glacier Change In Glacier And Mount Rainier National Parks, Brianna Clark May 2020

Applications Of Digital Remote Sensing To Quantify Glacier Change In Glacier And Mount Rainier National Parks, Brianna Clark

Electronic Theses and Dissertations

Digital remote sensing and geographic information systems were employed in performing area and volume calculations on glacial landscapes. Characteristics of glaciers from two geographic regions, the Intermountain Region (between the Rocky Mountain and Cascade Ranges) and the Pacific Northwest, were estimated for the years 1985, 2000, and 2015. Glacier National Park was studied for the Intermountain Region whereas Mount Rainier National Park was representative of the glaciers in the Pacific Northwest. Within the thirty year period of the study, the glaciers in Glacier National Park decreased in area by 27.5 percent while those on Mount Rainier only decreased by 5.7 …


Coarse Root, Forest Litter, And Soil Organic Matter Contributions To Carbon Sequestration In Loblolly Pine (Pinus Taeda) Plantations In East Texas, William Wedge Aug 2019

Coarse Root, Forest Litter, And Soil Organic Matter Contributions To Carbon Sequestration In Loblolly Pine (Pinus Taeda) Plantations In East Texas, William Wedge

Electronic Theses and Dissertations

Understanding ecosystem carbon dynamics is of increasing importance with atmospheric carbon dioxide (CO2) concentrations on the rise. Land management strategies, such as land use conversion, effect ecosystem carbon cycling dynamics and can alter the quantity of carbon sequestered in vegetation and soils. In East Texas and much of the southern United States, there has been a trend of converting marginal pastureland into loblolly pine (Pinus taeda) plantations. This afforestation, like all other land use conversions, leads to a redistribution of carbon in vegetation and soil carbon sinks. In 2003, five marginal pasturelands in East Texas were afforested with loblolly pine …


Soil Amelioration And Plant Establishment On Sodium Affected Soils On Galveston Island, Texas, Elaine Harris Aug 2019

Soil Amelioration And Plant Establishment On Sodium Affected Soils On Galveston Island, Texas, Elaine Harris

Electronic Theses and Dissertations

The storm surge from Hurricane Ike in 2008 inundated much of Galveston Island, Texas, causing lasting below-ground impacts in the form of elevated soil sodium (Na+) concentrations. The Na+ initially killed much of the vegetation on the Island and its persistence in soils and groundwater slowed revegetation with some species. Soil amelioration techniques aimed at reducing soil Na+ concentrations were evaluated on an area affected by the storm surge. The treatments were: constructed raised beds composed of uncontaminated soil, incorporation of organic mulch, gypsum application, and combinations of these treatments. Inputs of Na+ from sea-spray aerosols were also quantified using …


Facies And Diagenesis Analyses Of The Fort Terrett Formation Of The Lower Cretaceous Edwards Group, Near Junction, Texas, Richard Alden Urwin Jr. May 2019

Facies And Diagenesis Analyses Of The Fort Terrett Formation Of The Lower Cretaceous Edwards Group, Near Junction, Texas, Richard Alden Urwin Jr.

Electronic Theses and Dissertations

The Fort Terrett Formation was deposited on the western edge of the Comanche Shelf in central Texas. The predominate lithology of the Fort Terrett Formation is limestone which caps the hills that surround Junction, Texas. Deposition of the Fort Terrett Formation occurred within shallow, quiet waters during the Lower Cretaceous. Rose (1974) developed a general stratigraphic correlation and lithostratigraphic framework for the Cretaceous Shelf and established a regional correlation. Four stratigraphic divisions have been recognized in the Fort Terrett Formation. These are: a basal nodular unit, a burrowed unit, a dolomitic unit, and the Kirschberg evaporites. Wilkerson (2018) provided the …


Mercury In Big Cypress Bayou And Caddo Lake Watersheds In Marion And Harrison Counties Texas, Joseph Watkins Dec 2018

Mercury In Big Cypress Bayou And Caddo Lake Watersheds In Marion And Harrison Counties Texas, Joseph Watkins

Electronic Theses and Dissertations

Caddo Lake has been included on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury (Hg) content since 1996. One of the primary tributaries, Big Cypress Bayou, flows across Eocene-aged rocks and sediments associated with the Wilcox Group; the Wilcox is of interest because it contains lignite coal, which has a direct link to mercury. Previous research has focused on dry deposition from fossil fuel combustion as the primary source of mercury but has not addressed the potential watershed contribution to mercury concentrations in Caddo Lake.

Big Cypress Bayou flows through Harrison and Marion counties in …


Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles Dec 2018

Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles

Electronic Theses and Dissertations

The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …


Effectiveness Of Prescribed Fire On Meeting Fuel Load And Wildlife Habitat Management Objectives In East Texas National Forests, Trey Wall Dec 2018

Effectiveness Of Prescribed Fire On Meeting Fuel Load And Wildlife Habitat Management Objectives In East Texas National Forests, Trey Wall

Electronic Theses and Dissertations

Using standardized methodology outlined by the United States Forest Service and the National Forests and Grasslands in Texas’ Fire Monitoring Program for data collection, the efficacy of current Forest Service prescribed burn regimes were analyzed for 24 study sites in East Texas National Forests. Study sites were located within Sam Houston, Davy Crockett, and Angelina/Sabine National Forests. Efficacy was determined by comparing defined management objectives established by the Forest Service to the data collected at the study sites. The results conclude that most objectives, as outlined by the Forest Service, are not being met with the current practices. Re-visitation of …


Economics Of Managing Loblolly Pine Plantations For Increased Wildlife Biodiversity, Melissa Griffith Aug 2018

Economics Of Managing Loblolly Pine Plantations For Increased Wildlife Biodiversity, Melissa Griffith

Electronic Theses and Dissertations

The goal of this thesis was to identify the differences between the costs incurred and revenues gained from managing loblolly pine (Pinus taeda) plantations in East Texas for strictly timber production or a combination of timber production and wildlife biodiversity. Management regimes evaluated had varying planting densities, thinning frequency and intensities, prescribed burn intervals, and site indices. Economic analyses used to evaluate management regimes over a range of nonindustrial private landowner (NIPF) alternative rates of return (ARRs) and site indexes were net present worth, land expectation value, and equal annual annuity. These economic analyses demonstrated that altering management …


Speleogenetic Evolution And Geological Remote Sensing Of The Gypsum Plain, Eddy County, New Mexico, Jessica Shields May 2018

Speleogenetic Evolution And Geological Remote Sensing Of The Gypsum Plain, Eddy County, New Mexico, Jessica Shields

Electronic Theses and Dissertations

Permian evaporites of the Gypsum Plain region of the Delaware Basin host extensive karst phenomena, as well as unique diagenetic alterations of host strata. Because of the complex, poorly understood hydrogeologic system, little has been established concerning the relation and evolution of the overprinted, modern and ancient karst manifestations within the Gypsum Plain, as a whole. Through a combination of traditional field studies and the development of improved remote sensing methodologies, this study established the speleogenetic evolution of the Gypsum Plain in relation to the greater tectonic, stratigraphic, hydrogeologic and climatic history of the Delaware Basin. Emphasis was focused on …


A Comparison Of Four Wetlands Assessment Procedures Relevant To The Alluvial Valleys Of East Texas, Amy Camp May 2018

A Comparison Of Four Wetlands Assessment Procedures Relevant To The Alluvial Valleys Of East Texas, Amy Camp

Electronic Theses and Dissertations

Currently several methods are used by public and private entities to assess wetland functional condition in support of the Section 404 Clean Water Act program. Four of these are: Forested Wetlands in Alluvial Valleys of the Coastal Plain of the Southeastern United States (SEHGM); A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment of Forested Wetlands in Alluvial Valleys of East Texas (ETXHGM); Texas Rapid Assessment Method (TXRAM); and the Wildlife Habitat Appraisal Procedure (WHAP). Little previous research compares wetland functional assessment methods. Results of the SEHGM, ETXHGM, TXRAM, and WHAP methods were compared on five East …


Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard Dec 2017

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …


Spatially Explicit Model Of Areas Between Suitable Black Bear Habitat In East Texas And Black Bear Populations In Louisiana, Arkansas, And Oklahoma, Caitlin M. Glymph, Christopher Comer, Daniel Scognamillo, Daniel Unger, Yanli Zhang Nov 2017

Spatially Explicit Model Of Areas Between Suitable Black Bear Habitat In East Texas And Black Bear Populations In Louisiana, Arkansas, And Oklahoma, Caitlin M. Glymph, Christopher Comer, Daniel Scognamillo, Daniel Unger, Yanli Zhang

Electronic Theses and Dissertations

Although black bears (Ursus americanus, Ursus americanus luteolus) were once found throughout the south-central United States, unregulated harvest and habitat loss resulted in severe range retractions and by the beginning of the twentieth century populations in Oklahoma, Louisiana, Texas and Arkansas were nearing extirpation. In response to these losses, translocation programs were initiated in Arkansas (1958-1968 & 2000-2006) and Louisiana (1964-1967 & 2001-2009). These programs successfully restored bears to portions of Louisiana and Arkansas, and, as populations in Arkansas began dispersing, to Oklahoma. In contrast, east Texas remains unoccupied despite the existence of suitable habitat in the region.

To facilitate …


Effects Of Ponderosa Pine Ecological Restoration On Forest Soils And Understory Vegetation In Northern Arizona, Elena M. Thomas, Kenneth W. Farrish, Brian P. Oswald, Melinda G. Shaw-Faulkner, Scott R. Abella May 2017

Effects Of Ponderosa Pine Ecological Restoration On Forest Soils And Understory Vegetation In Northern Arizona, Elena M. Thomas, Kenneth W. Farrish, Brian P. Oswald, Melinda G. Shaw-Faulkner, Scott R. Abella

Electronic Theses and Dissertations

The human exclusion of wildfire and overgrazing by livestock since settlement have caused dramatic changes in ponderosa pine (Pinus ponderosa Dougl ex Laws) forest ecosystems. These changes include increased numbers of tree stems, reduced understory cover and diversity, and the introduction of invasive, non-native understory species. This study evaluated the coverage and species composition of understory vegetation present in the “cool-season” (late spring and early summer) in a ponderosa pine forest on grazed and ungrazed plots that had undergone restoration treatments on three different soil/geologic parent material types near Flagstaff, Arizona, twelve years after tree thinning and grazing exclosure …


Assessment And Characterization Of Microbial Communities In Salt Affected Soils On Galveston Island, Elaine Fowler May 2017

Assessment And Characterization Of Microbial Communities In Salt Affected Soils On Galveston Island, Elaine Fowler

Electronic Theses and Dissertations

After Hurricane Ike in 2008, Galveston Island was flooded with sea water that left the soil and groundwater of the island with elevated sodium concentrations. As part of a long-term study that aims to restore plant life to the island, various soil amelioration techniques are being evaluated. Samples from bedded and non- bedded plots treated with gypsum, mulch, or both were assessed for microbial populations. Samples collected in July and October 2016 were cultured on Tryptic Soy Agar (bacteria enumeration), Pseudomonas Agar, Actinomycete Agar, and Rose Bengal Agar (fungi enumeration). Bacteria populations ranged from 4.07 to 5.12 log CFU/gram and …