Life Sciences Commons^™

Quantification Of Influential Surface Fuel Parameters In Fire-Prone Ecosystems Of The Netherlands, Lauren Lara

Electronic Theses and Dissertations

Changing climate conditions in northwest Europe present an increasing wildfire risk in the Netherlands. Focus on fuels monitoring in this region is not as extensive as it is in the United States. Accurate estimation of biomass fuel loading is integral to prevention of wildfires which pose a significant risk to both human lives and property. This research project attempted to create predictive models for three major fuel categories (litter/duff, shrub, and downed woody material). Reduction of the number of parameters to measure would streamline the process of fuel load estimation by reducing the number of measurements that need to be …

Contrasting Orthophotos By Height, Overlap, And Drone, Edward Ironsmith

Graduate Research Conference

Drones have recently become a mainstay for surveying and modeling of small areas of land in a cost-efficient manner. Yet there are many variables that affect the time, quality, and cost of capturing and generating such products. We look at several of these parameters and discuss the alternatives to minimize cost over a series of projects. The parameters in question include height, overlap, sensor resolution, processing time, drone costs, computer costs, processing costs, time in the field, storage, drone endurance and the likelihood of costly delays. A series of flights using different drones and flight parameters were then used to …

Demography Of Alligator Snapping Turtles (Macrochelys Temminckii) Across A Fishing Pressure Gradient, Luke Micek

Graduate Research Conference

Demographic data are necessary to predict population responses to environmental and anthropogenic stressors and inform conservation efforts for declining species (Weimerskirch 2018, J.Wildl. Manag.).

The western alligator snapping turtle (Macrochelys temminckii; hereafter AST; Fig. 5) is the largest species of freshwater turtle in North America and is being considered for Federal listing as a Threatened Species under the Endangered Species Act (Federal Register 2021). Notably, there is a lack of demographic data of AST in Texas.

Passive fishing gear (i.e., trotlines) have been identified as a pervasive threat to AST populations, although this threat has yet to be quantified inTexas …

Effects Of Prescribed Fire Regimes On White-Tailed Deer (Odocoileus Virginianus) Browse, Forage, And Nutrient Availability In The Pineywoods Ecoregion Of Texas, Wyatt L. Bagwell

Electronic Theses and Dissertations

Fire is a management tool for white-tailed deer (Odocoileus virginianus) habitat, influencing browse availability, herbaceous production, and nutrient content. In 2020 and 2021, this study utilized 46 plots across East Texas to assess these habitat components. A stem count index survey method was used to assess browse utilization prior to April in both years, and preferred browse species were clipped and analyzed for nutrient availability, and herbaceous production was also measured. Additionally, white-tailed deer population data, browse survey data, and recent fire history were obtained from five different wildlife management areas to examine their relationship. Deer had preferences …

Soil Quality Indicators And Vegetation Responses Following Ecological Restoration Thinning Of Ponderosa Pine On Three Soil Parent Material Types Under Grazing And Non-Grazing In Northern Arizona, Christopher Macdonald

Electronic Theses and Dissertations

This research was performed in a northern Arizona ponderosa pine (Pinus ponderosa P. & C., Lawson) forest. The objectives were to a) increase understanding of long-term vegetation responses to ecological restoration treatments on three soils types, with and without grazing, b) evaluate the responses soil physical, chemical, and biological properties to restoration treatments, with and without grazing, c) determine the utility of measured soil quality indicators to informing risks to sustainable soils management in southwestern ponderosa pine forests.

There were no significant differences in soil bulk density by soil type, treatment type, or grazing treatment. No significant differences …

Restoration Through Reassembly: Evaluating The Role Of Native Plants In Combatting Chinese Tallow, Olaniyi Ajala

Electronic Theses and Dissertations

Non-native, invasive species disrupt ecological processes and functions, posing a serious threat to natural ecosystems. By examining the growth metrics of the non-native, invasive tree, Chinese tallow (Triadica sebifera [L.] Roxb.), hereafter tallow, across different flooding and light regimes, I investigated how restructuring native communities with valuable native species will prevent the reestablishment of tallow. I studied the changes in morphological and physiological traits of tallow when growing with water tupelo (Nyssa aquatica L.), sugarberry (Celtis occidentalis L.), and green ash (Fraxinus pennsylvanica Marshall). I found that in the non-flooded and high irradiance treatments, tallow's growth …

Detection, Occupancy, Abundance, And Mercury Accumulation Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Texas, David Rosenbaum

Electronic Theses and Dissertations

Land use practices and physical alterations of ecosystems result in habitat loss and fragmentation, while chemical alterations, such as pollutant input, reduce habitat quality and health of exposed organisms. Here, I investigated the effects of watershed- and local-scale environmental variables on the occupancy, abundance, and mercury accumulation of a threatened aquatic species (Macrochelys temminckii, i.e., alligator snapping turtle) within the southwestern periphery of its distribution. Hierarchical modeling suggested the distribution of the species is more affected by watershed-scale land-cover than local habitat, and provided a baseline estimate of average species abundance across its range in eastern Texas. Abundance …

Spatiotemporal Factors Affecting The Occupancy And Phenology Of A Declining Songbird (Bachman's Sparrow - Peucaea Aestivalis) At The Western Extent Of Its Range, Liam G. Wolff

Electronic Theses and Dissertations

The Bachman’s Sparrow (Peucaea aestivalis) is a declining songbird that occurs throughout the southeastern United States. Bachman’s Sparrow is a Species of Greatest Conservation Need in Texas, but information crucial to management efforts, such as factors affecting their detectability and occupancy, is lacking. I investigated the predictors of Bachman’s Sparrow occupancy and phenology in Texas using detections from autonomous recording units coupled with site characteristics and weather data. My results indicate that Bachman’s Sparrow occupancy is associated with increasing herbaceous ground cover and decreasing basal area, distance to the nearest source population, and basal area when canopy height …

Conk1 - Forest Pathology Specimen, Robert Z. Selden Jr.

CRHR: Archaeology

Pathology specimen.

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

Natural Regeneration Dynamics And Survival Influenced By Abiotic And Biotic Factors In A Bottomland Hardwood Forest, Lydia J. Voth Rurup

Electronic Theses and Dissertations

Riparian ecosystems are vital to the landscape, providing critical services including water filtration and purification, flood and erosion control, carbon sequestration, biodiversity support, and aesthetic value. Bottomland hardwood forests, however, are threatened by invasive species, land loss/conversion, inconsistent or absence of harvesting disturbances, and altered hydrological patterns, leading to reduced success of desired, native species. This research assessed regeneration dynamics and one-year survival in a seasonally-flooded bottomland hardwood forest at Boggy Slough Conservation Area in East Texas to identify abiotic and biotic factors important for successful establishment of native regeneration. Areas sampled included two that were previously treated with herbicide …

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado

Electronic Theses and Dissertations

Kiwifruit is a perennial vine originating from China where it has been grown for centuries. In the United States, green kiwifruit (Actinidia deliciosa) is primarily produced commercially in California. They are fuzzy, green fleshed and well known in the marketplace. Kiwifruit plants require low to moderate soil pH, adequate winter chilling and adequate precipitation to guarantee plant development and good fructification. Actinidia chinesis or golden kiwifruit are smooth skinned, feature golden flesh and are a more recent introduction into the global market. Kiwifruit crops have attributes that favor production in east Texas, including low pest problems, current long …

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 …

Food-Web And Functional Trait Community Structure Of Predator Assemblages In Pine Forests Under Different Management Regimes, Connor Adams

Electronic Theses and Dissertations

Anthropogenic activities can alter natural disturbance regimes in ecosystems, and thereby affect the structure and function of biological diversity. As many of the world’s ecosystems are degraded beyond natural recovery, well-defined restoration goals are necessary to maintain the ecological processes that provide valuable ecosystem services. Utilizing taxonomic, functional, and food-web approaches, I investigated the impacts of forest management practices in structuring predator communities in two pine forest systems of eastern Texas. The results of this study indicate that the increased frequency of forest management practices such as prescribed fires and thinning operations encourages predator diversity while increasing functional and trophic …

Pine Habitat Characteristics Associated With Variation In Chuck-Will’S-Widow Communities, Hannah E. Beckett

Undergraduate Research Conference

This study explores the potential impact of variation in forest habitats and management on Chuck-will’s-widow density.

Payment For Ecosystem Services: Rewarding The Landowner Who Conserves The Public Good, Steven H. Bullard, Sarah Fuller

Faculty Publications

It has been said that money doesn’t grow on trees, but any forest landowner or manager will tell you that’s not exactly true— especially when observing a harvesting operation or managing dues from your hunting lease. While timber production and recreation are the most frequently monetized services provided by forests, what about the other goods and services they provide on a continuing basis? Are you or other forest landowners in your area being monetarily rewarded for soil stability, flood control, water filtration, air quality, and the other critical services—known as ecosystem services—provided by forests?

Measuring Building Height Using Point Cloud Data Derived From Unmanned Aerial System Imagery In An Undergraduate Geospatial Science Course, David L. Kulhavy, I-Kuai Hung, Daniel R. Unger, Reid Viegut, Yanli Zhang

Faculty Publications

The use of Unmanned Aerial Systems (UAS), also known as drones is increasing in geospatial science curricula within the United States. Within the Arthur Temple College of Forestry and Agriculture (ATCOFA) at Stephen F. Austin State University, Texas, seniors in the geospatial science program complete capstone projects to evaluate current geospatial technology to investigate complex ecological, social and environmental issues. Under the umbrella of a student initiated and designed senior project, students designed a study to estimate height of buildings with UAS data incorporating UAS data, LP360 and ArcScene programs, and Pictometry web-based interface. Results from a statistical analysis of …

Use Of Altmetrics To Analyze Scholarworks In Natural Resource Management, David L. Kulhavy, R Philip Reynolds, Daniel R. Unger, Matthew W. Mcbroom, I-Kuai Hung, Yanli Zhang

Faculty Publications

Digital preservation of library materials has increased the need for methods to access the documents and contents maintained in digital archives. The use of altmetrics to quantify the impact of scholarly works, including PlumX, is increasing readership by listing articles in reference services. The outreach from the digital repository ScholarWorks at Stephen F. Austin State University (SFASU) highlights the impact within the natural resources community from Digital Commons, Forest Sciences Commons; and from the Natural Products Chemistry and Pharmacognosy Commons. The use of PlumX altmetrics was examined to evaluate usage, impact, and digital audience downloads for the Arthur Temple College …

Reconstruction Of Piñon–Juniper Woodlands In The Sky Islands Of The Davis Mountains, Texas, Usa, Mohammad Bataineh, Brian P. Oswald, Hans M. Williams, Dan Unger, I-Kuai Hung

Faculty Publications

Piñon (Pinus spp. L.)–juniper (Juniperus spp. L.) woodlands’ historical stand structures were recreated to provide reference conditions and document long‐term changes in the Sky Islands of the Davis Mountains, Texas. Restoration of these isolated woodlands requires insights into the range of variability in current and historical stand structures, as well as an understanding of the spatiotemporal establishment and recruitment patterns of tree species. With drastic changes in forests and woodlands of the Southwestern United States widely reported, the main objective of this study was to reconstruct woodland tree temporal and spatial establishment patterns. A stratified random sampling approach was used …

Initial Establishment Success Of Five Forages In An East Texas Loblolly Pine (Pinus Taeda) Silvopasture, Michael Richard, Ken Farrish, Brian P. Oswald, Hans M. Williams, Michael Maurer

Faculty Publications

The establishment at the end of 1 year of five forages was evaluated in a loblolly pine (Pinus taeda L.) silvopasture system. The five forages were: ‘Pensacola” bahiagrass (Paspalum notatum Fluegge), “Texas Tough” bermudagrass (Cynodon dactylon L. Pers.), “Alamo” switchgrass (Panicum virgatum L.), “San Marcos” Eastern gamagrass (Tripsacum dactyloides L.), and a native mix containing 45% “Texas” little bluestem (Schizachyrium scoparium Michx Nash), 15% sand lovegrass (Eragrostis trichodes Nutt. L. Alph. Wood), 15% “Blackwell” switchgrass (Panicum virgatum L.), 10% “Lometa” indiangrass (Sorgastrum nutans L. Nash), 10% “Haskell” sideoats grama (Bouteloua …

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 …

Preliminary Flammability Assessment Of Sea Buckthorn From The Netherlands Compared To Known Flammable Shrubs Of The Southern And Western Us, Michael Tiller, Brian P. Oswald, Mathijs Schuijn

Faculty Presentations

Sea buckthorn (Hippophae rhamnoides) is a common coastal species in The Netherlands that potentially burns with extreme energy levels. In this region of Europe that is experiencing increases in wildfire events, the need to gain a greater understanding of energy released when this species burns will improve fire behavior predictions. The objective of this study was to conduct an initial investigation into the foliage flammability of sea buckthorn to a common southern United States native shrub known for its flammability, yaupon (Ilex vomitoria), and two common dominant shrub species in California chaparral, chamise (Adenostoma fasciculatum …

Initial Investigation Of Seasonal Flammability Of Three Invasive East Texas Forest Understory Fuels Using Thermogravimetric Analysis, Mike Tiller, Brian P. Oswald, Alyx Frantzen, Warren Conway, Ikuai Hung

Faculty Publications

East Texas forest understory fuels have become increasingly infested with invasive species which have contributed to greater hazardous fuel loads when combined with decades of fire exclusion and passive management. This study focused on estimating seasonal changes in flammability parameters of invasive yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), and Chinese tallow (Triadica sebifera) using thermogravimetric analysis. Foliage and stem samples were collected in the dormant (February) and growing (August) seasons. Differential thermogravimetric (DTG) and proximate analyses were used to estimate species specific flammability parameters related to relative spontaneous ignition temperature (RSIT), gas-phase maximum …

Initial Investigation Of Seasonal Flammability Of Three Invasive East Texas Forest Understory Fuels Using Thermogravimetric Analysis, Michael Tiller, Brian P. Oswald, Alyx Frantzen, Warren Conway, I-Kuai Hung

Faculty Presentations

East Texas forest understory fuels have become increasingly infested with invasive species which have contributed to greater hazardous fuel loads when combined with decades of fire exclusion and passive management. This study focused on estimating seasonal changes in flammability parameters of invasive yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), and Chinese tallow (Triadica sebifera) using thermogravimetric analysis. Foliage and stem samples were collected in the dormant (February) and growing (August) seasons. Differential thermogravimetric (DTG) and proximate analyses were used to estimate species specific flammability parameters related to relative spontaneous ignition temperature (RSIT), gas-phase maximum …

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 …

Does Installation Method Affect Snake Entanglement In Erosion Control Blankets?, Nicholas C. Schiwitz, Kasey L. Jobe, Krista J. Ward

Undergraduate Research Conference

Erosion control blankets (ECBs) are installed at construction sites to mitigate against soil loss and promote plant growth. Wildlife, particularly snakes, are prone to becoming entangled in ECBs that contain fixed‐intersection, small‐diameter polypropylene mesh with multiple layers (Ebert et al. 2019 Wildl. Soc. Bull.; Fig. 1).

The majority of ECBs on the Texas Department of Transportation’s Approved Product List contain fixed-intersection mesh, which pose a risk to snakes.

Snake entanglements often occur at the edge of an ECB where the snake often passes between the multiple mesh layers (Ebert et al. 2019 Wildl. Soc. Bull.)

Burying the edge of an …

Mediterranean House Geckos Exploit Novel Resources In A Recipient Lizard Assemblage, John M. Arnett, Connor S. Adams, Carmen G. Montana

Undergraduate Research Conference

A species’ ecological niche represents the environmental conditions needed for an individual to replace itself and is comprised of multiple resource axes (Pianka 2000 Evol. Ecol.).

One mechanism of establishment of non-native species is via exploitation of novel resources in recipient ecosystems through their unique functional traits (Schalk et al. 2018 Biol. Invas.).

Mediterranean House Geckos (Hemidactylus turcicus) are an exotic species introduced in urban areas across Texas, yet little is known about their resource use relative to native lizards.

We hypothesized that H. turcicus would exhibit low overlap in resource use in their habitat, dietary, and isotopic niches compared …

On The Diversity Of Erosion Control Products: Implications For Snake Entanglement, Kasey L. Jobe, Nicholas C. Schiwitz, Krista Ward

Undergraduate Research Conference

After a road construction project, Texas Department of Transportation (TxDOT) mandates that erosion control products (ECPs) are installed to prevent soil loss and promote plant growth. However, their presence on the landscape pose negative consequences to wildlife via entanglement.

TxDOT provides an Approved Products List (APL) of ECPs meeting soil erosion prevention and plant growth standards. In Texas, multiple types of ECPs are produced with a range of materials and attributes to decrease the erosion potential on multiple soil types and slopes. Certain attributes are more likely to lead to snake entanglement (Ebert et al. 2019 Wildl. Soc. Bull.; Fig. …

An Integrated Method For Coding Trees, Measuring Tree Diameter, And Estimating Tree Positions, Linhao Sun, Luming Fang, Yuhi Weng, Siqing Zheng

Faculty Publications

Accurately measuring tree diameter at breast height (DBH) and estimating tree positions in a sample plot are important in tree mensuration. The main aims of this paper include (1) developing a new, integrated device that can identify trees using the quick response (QR) code technique to record tree identifications, measure DBH, and estimate tree positions concurrently; (2) designing an innovative algorithm to measure DBH using only two angle sensors, which is simple and can reduce the impact of eccentric stems on DBH measures; and (3) designing an algorithm to estimate the position of the tree by combining ultra-wide band (UWB) …

Activity Level-Predation Risk Tradeoff In A Tadpole Guild: Implications For Community Organization Along The Hydroperiod Gradient, Nicholas C. Schiwitz, Christopher M. Schalk, Daniel Saenz

Faculty Publications

Increasing activity levels permit greater food intake for use towards growth and reproduction, consequently increasing predation risk via increased detection. Larval anurans are models to examine activity level-predation risk tradeoffs, as they occupy a variety of lentic habitats that impose constraints on the distribution and abundance of species. Ephemeral ponds have a low abundance and diversity of predators and as a result tadpole species tend to have high foraging rates for rapid development. Permanent ponds generally possess a greater diversity and abundance of predators and tadpoles inhabiting these locations tend to have low activity rates or chemical defenses to minimize …