Forest Sciences Commons^™

The Effect Of An Invasive Species (Lantana Camara) And A Fast-Growing Herb (Acanthus Pubescens) On The Plant And Animal Communities In Kibale National Park, Uganda, Kathleen Bufka

Theses and Dissertations

Fast-growing plant species, like Lantana camara and Acanthus pubescens, could threaten biodiversity in Kibale National Park, Uganda. I surveyed plants and wildlife in areas where these plants were frequently encountered compared to those areas where they are infrequent. I found mixed results based on plant traits and the animals considered. My findings support management efforts on these two species to prevent forest degradation.

Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts

Theses and Dissertations

The vegetation of the Amazonian rainforest is hypothesized to have been shaped by pre-Columbian activities, such as burning and palm management to various extents. Management of palms is hypothesized to have caused some of the most useful species to become hyperdominant in Amazonia. This study investigated the extent to which human activities over the past 5000 years affected palm abundances in mature lowland rainforests near Iquitos, Peru. I used phytoliths and charcoal from soil cores to determine the history of local floras, and modern palm surveys to compare modern phytolith occurrence with modern vegetation. Because pre-Columbian activity clustered along the …

Climate Resilience In Texas Assessing The Impact Of Extreme Weather On Energy Poverty And The Mitigating Role Of Tree Canopy Coverage, Yongwen Yang

Theses and Dissertations

Extreme weather events, including severe heat and cold waves —increasingly threaten public health, economic stability, and energy equity. This two-part study examines the interplay between extreme weather, energy poverty, and green infrastructure (tree canopy coverage) in Texas, a state characterized by climatic extremes and socioeconomic diversity.

This study consists of four chapters. The first chapter in the Introduction includes the research background, existing research, research gaps, research questions, and potential contributions. Followed by two core chapters. Chapter II aims to assess the impact of extreme weather on energy poverty at the household level. Chapter III aims to identify whether tree …

Forest Above-Ground Biomass Estimation Using Nasa Gedi Lidar Waveforms And Global Tree Allometry, Ian Grant

Theses and Dissertations

Above-ground forest biomass plays a crucial role in global carbon cycles, yet accurately estimating biomass at global scales remains challenging. This thesis addresses two key challenges in processing NASA’s Global Ecosystem Dynamics Investigation (GEDI) space-borne lidar data to estimate above-ground biomass density (AGBD): accounting for global variation in forest structure and developing robust physical interpretations of lidar returns. The first component of the thesis analyzes global patterns of tree allometry using the Tallo tree allometry dataset, examining relationships between tree dimensions across biomes, continents, and plant functional types. This analysis reveals consistent allometry across continents for some biomes (e.g., tropical …

A Nursery Study Of The Interplay Between Soil Texture, Rooting Space, And Nurse Plants On Seedling Growth And Root Development In Woody Species Of Tamaulipan Thornscrub, Lance I. Santos

Theses and Dissertations

Reforestation attempts in semi-arid regions are plagued with seedling mortality. Blanket greenhouse practices may not be optimal, in addition, commensalism interactions between nurse plants are considered. To better understand the effects of soil texture and nurse plant interactions on growth and drought tolerance, two experiments were developed. For soil texture, Border palo verde seedlings were grown in different-sized plant bands with three soil types. To observe the effects of nurse plants, an experiment using guayacan, was developed using Texas Ebony, as a leguminous nurse plant. Plants were also exposed to a drought experiment. The results suggest that some soil textures …

Mapping Urban Tree Canopy Using Publicly Available Satellite Data, Rosemary Mcguinness

Theses and Dissertations

This project addresses the need for accessible, cost-effective tools for quantifying spatial and temporal changes in tree canopy cover in urban areas. Urban tree canopy provides a wide range of ecosystem services, including lowering air temperatures, reducing pollution, and mitigating stormwater runoff. Cities around the world have placed the expansion of their urban forests at the center of their sustainability goals. Consistent and timely data on urban tree canopy is essential for urban greening initiatives to succeed. Existing methods of accessing information about urban tree canopy are highly technical, costly, and labor-intensive, while the freely available source of tree canopy …

Utilizing Unmanned Aerial Systems (Uas) And Computer Software To Assess Effects Of Cover Crops On Cash Crop Volumetric Mass And Plant Height, Carlos Andres Garcia Patlan

Theses and Dissertations

Sustainability in agriculture starts with the health of soil-- from its productivity and fertility, to its ability to retain water during droughts and allow for drainage during rain. One approach of improving soil health is the use of cover crops, a practice associated with improved nutrient availability in soils, the promotion of soil biodiversity and organic matter to improve density and structure, effective weed management, and ultimately improved yields of subsequent cash crops. Assessing the cumulative impacts of cover crops is difficult, with various metrics and indicators. Crop dry weight may be a way to predict the effects cover crops …

Leaf To Canopy Functional Resilience: Plant Physiological And Carbon Cycling Stability Following Disturbances, Lisa T. Haber

Theses and Dissertations

Ecological disturbances impact core ecosystem functions, including production and biogeochemical cycling, by precipitating changes in biodiversity, physical environmental variables, vegetation structure, and functional trait distributions. As disturbance patterns intensify and abruptly transition to novel regimes under global change, future trajectories of ecosystem functions, including carbon (C) uptake and storage, are uncertain. A more complete understanding of the mechanisms underpinning ecosystem stability (or ability to return to baseline functioning) following disturbance is needed to forecast future C cycling.

Replicated ecosystem-scale disturbance experiments, particularly when coupled with modeling, are required to rigorously test hypothesized trajectories of ecosystem structural and functional change following …

Evaluating Selected Properties Of Underutilized Hardwood Species For Fabrication Of Cross-Laminated Timber Industrial Mats, Mercy Itunu Ogunruku

Theses and Dissertations

Softwood is more in demand than hardwood because it is used primarily in the US's largest wood-consuming industry, construction, resulting in increased importation of softwood annually to meet this demand. Hardwood, used for non-structural purposes like furniture and interior designs, is more abundant in US forests. However, some hardwood species are underutilized and undervalued. Cross-laminated timber (CLT) has increased the demand for softwood.

A study evaluated the mechanical and physical properties of three underutilized hardwood species (321 yellow poplar, 393 sweetgum, and 262 red oak specimens) for CLT industrial mat manufacturing. The results showed that red oak had a higher …

An Assessment Of Loblolly Pine (Pinus Taeda L.) Mortality And The Impact Of Habitat Fragmentation On Southern Pine Beetle (Dendroctonus Frontalis Zimmerman) Infestation In Mississippi, Usa, Damilola M. Taiwo

Theses and Dissertations

This thesis has two data chapters that consider factors affecting loblolly pine health in localized regions of Mississippi. The first data chapter investigated the abiotic and biotic factors contributing to loblolly pine (Pinus taeda) mortality on private timberland in Mississippi. This assessment considered temperature and precipitation variations, bark beetle populations, foliar and root pathogen tests, and drone survey. The results revealed that the loblolly pine mortality resulted from combination of factors. The second data chapter examined the impact of habitat fragmentation on southern pine beetle (SPB; Dendroctonus frontalis) infestation in Homochitto National Forest (HNF). This was assessed through remote sensing …

Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura

Theses and Dissertations

I investigated the effect of climate change in one of the few expanding markets in the world in Brazil. In the last decades the demand for pulpwood increased from zero to 11 million tons, leading to an expansion of 700 thousand hectares of Eucalyptus plantation. In 2024, a new mill will start operating increasing the consumption of wood fiber by 8.2 million tons (+49%). I used mathematical programming to investigate how different scenarios of productivity and land will affect the market. My results showed that around 946,000 hectares (+124%) of additional timberland will be necessary in the upcoming decades. The …

Heirs' Property Disputes On Forestlands, Partition Actions, And The Determinants Of Court Verdicts, Mahesh Prasad Tiwari

Theses and Dissertations

Heirs' property is generated through the intergenerational transfer of a property to several co-owners when the original owner dies without a will. Such co-owners hold undivided fractional interest in the entire land but lack a clear title. Co-owners face several legal, financial, and technical constraints to manage the forestlands and often seek partition of the land. However, the legal environment and empirical assessment of partition actions on forestlands owned as heirs' property has not been examined. This thesis evaluates statutory laws relevant to forestland partition and the factors instrumental in adjudicating partition lawsuits. The findings reveal that partition lawsuits are …

Timing Is Everything: Impacts Of Firing Technique And Season On Plant Communities In The Southeastern United States, Luke Michael Resop

Theses and Dissertations

Prescribed fire is a common land management tool in the southeastern United States. Historical fires occurred primarily in the growing season, but modern day prescribed fire is commonly restricted to the dormant season. Plant community responses to various fire regimes are relatively unknown, and managers require information on how fire regimes impact plant communities. To address these limitations, I studied the impacts of March and June fire on plant communities. Results indicated various woody midstory species respond differently to fire season and community response is driven by species composition. In another study, I examined impacts of February, May-June, and September-October …

Small Area Estimation Of County-Level Forest Attributes Using Forest Inventory Data And Remotely Sensed Auxiliary Information, Okikiola Michael Alegbeleye

Theses and Dissertations

The Forest Inventory and Analysis (FIA) program of the United States Department of Agriculture Forest Service collects forest inventory data that provide estimates with reasonable accuracy at the national scale. However, for smaller domains, these estimates are often not as accurate due to the small sample size. Small area estimation improves the accuracy of the estimates at smaller domains by relying on auxiliary information. This study compared direct (FIA estimates), indirect (multiple linear regression), and composite estimators (Fay-Herriot) using auxiliary information derived from Landsat and Global Ecosystem Dynamics Investigation (GEDI) to obtain county-level estimates of forest attributes namely total and …

A Four-Pronged Approach To Addressing A Wild Pig Invasion In A Bottomland And Upland Forested Landscape, Tyler Scott Evans

Theses and Dissertations

Among exotic species that are capable of invading, establishing, and reaching pest status, few pose the range of impacts to biotic (e.g., competition with native species, predation, herbivory, introduction of other exotics) and abiotic (e.g., soil, hydrology) ecosystem components that can be attributed to the wild pig (Sus scrofa). Despite the presence of wild pigs throughout the southeastern United States for centuries, new invasions continue to occur in previously uninhabited and often under-investigated landscapes, including bottomland and upland forests. The recent invasion of the Sam D. Hamilton Noxubee National Wildlife Refuge (hereafter, NNWR) in east-central Mississippi represents an …

Maximum Size-Density Relationships In Mixed-Species And Monospecific Stands Of The Southeastern United States, Maxwell Robert Schrimpf

Theses and Dissertations

Maximum size-density relationships (MSDR) are used to quantify differences across sites in the number of trees of a given size and species that can be supported per hectare. These relationships are important to managers who are trying to maximize basal area and wood volume. In my study, I examined MSDR across Alabama, Georgia, Louisiana, and Mississippi using US Forest Service, Forest Inventory and Analysis (FIA) data. I determined the impact of species-specific, specific gravity, functional traits, and environmental factors on MSDR using a quantile regression approach. Overall, I found that climatic factors had the greatest influence on MSDR, and that …

A Silvicultural Approach To Increase Drought Resistance And Resilience In Longleaf Pine, Kyle R. Dues

Theses and Dissertations

Droughts are a common disturbance experienced by forest systems across the southeastern United States and are expected to increase in frequency in the near future. Few empirical studies have evaluated the response of individual tree resistance and resilience following silvicultural treatment in longleaf pine (Pinus palustris Mill.). This study evaluates the differences in drought responses between two forests during three different periods. The first period evaluated pretreatment (2000) conditions, while the second (2006), and third (2011) compared conditions after the implementation of five silvicultural treatments. The main findings are that, as additional basal area is removed, both individual tree …

Development Of Hydrophobic Paper And Wood Products Via Metal Ion Modification, Oshani Nayanathara Rathnayaka Mudiyanselage

Theses and Dissertations

Renewable lignocellulosic materials are promising green plastic alternatives to fossil fuel-based plastics. However, the hydrophilic nature and poor water resistance of lignocellulosic materials have hindered their practical applications. This study reports a facile metal-ion-modification (MIM) route, swelling with aqueous metal ion solutions, and drying to convert conventional hydrophilic paper and wood pulp into biodegradable hydrophobic paper and tableware without the addition of hydrophobic sizing chemicals/materials. Metal ions such as Fe3+ and Zr4+ can coordinate with pulp fibers’ polar groups (i.e., O.H., C=O, and COOH) that induce self-assembly of their surface fibrillated “hairy” cellulose nanofibrils to form a more compact structure …

Modeling The Effect Of Neighborhood Competition On Tree Diameter Growth In The Pacific Northwest Coast Range, Htet Lin Naing

Theses and Dissertations

Trees compete for various resources such as sunlight, water, and nutrients, which can be expressed as numerical terms, called competition indices (CI). Competition between individual trees is correlated with their growth and mortality. Therefore, CIs are used as independent variables to develop, improve and modify growth and yield models. This study was conducted to test the effect of neighborhood competition on tree diameter growth among Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg) and red alder (Alnus rubra Bong.), in the Pacific Northwest Coast Range, USA. After testing seven distance-independent CIs and three distance-dependent …

Development Of Preservative-Treated Cross-Laminated Timber And Lignin-Reinforced Polyurethane-Adhesive For Glued Laminated Timber, Samuel Oluwafemi Ayanleye

Theses and Dissertations

Interest in the use of mass timber in building and construction is growing worldwide, this is due to the structural integrity and reduced environmental footprint of timber-based structures. Concerns associated with the biological and environmental degradation of mass timber necessitate the development of adequate protection strategies to ensure the durability of these products. Preservative treatment is a proven technique that increases the durability and performance of wood in-service and can also be applied to large-sized timber panels such as cross-laminated timber (CLT). Therefore, this study focused on investigating the feasibility of treating prefabricated 3- and 5-layer CLT panels with Copper-azole …

Gene Expression Effects On Productivity And Stress Tolerance In Polyclonal Plantings Of Populus Deltoides, Macy Gosselaar

Theses and Dissertations

Polyclonal plantings of Populus deltoides are expected to display increased site resource use, productivity, and tolerance to stress through plasticity changes leading to niche differentiation (i.e changes to crown/canopy structures). In the present study, P. deltoides Clones S7C8, 110412, and polyclonal plots were tested for differentially expressed genes and enriched biological pathways between planting schemes. Transcriptomic analysis of leaves revealed upregulation of an active growth gene and gene family members that play important roles in plant stress and stress tolerance in polyclonal plantings. A gene associated with oxidative stress was upregulated in polyclonal plantings across all treatments. Secondary metabolic pathways …

Leaf Area Index And Aboveground Biomass Estimation Of Populus And Its Hybrids Using Terrestrial Lidar, Surya Adhikari

Theses and Dissertations

Short rotation woody crops (SRWC) eastern cottonwood (Populus deltoides) and hybrid poplar plantations were established in 2021 in Pontotoc and Oktibbeha counties of Mississippi to study the biomass potential of SRWC for biofuel production. We used a novel backpack LiDAR system to measure forest metrics and harvested sample trees to build aboveground biomass (AGB) and leaf area index (LAI) equations. The results showed that LiDAR-derived variables accurately estimated aboveground biomass (R² =0.81 and 29.22 % RMSE). However, the LAI estimation results showed that the LiDAR metrics moderately explained field measurements of LAI (R² =0.31 and 18.05% …

Effects Of Fire Seasonality On Bachman’S Sparrows In The Longleaf Pine Forests Of Southern Mississippi, Michael D. Warren

Theses and Dissertations

The Bachman’s sparrow (Peucaea aestivalis) is a ground-dwelling, pine-obligate species experiencing range-wide population declines due to land development and fire exclusion. We explored the effects of fire seasonality on wintering Bachman’s sparrow abundance in Southern Mississippi from 2021-2022. We used generalized linear mixed models to investigate differences in sparrow abundance and vegetation characteristics following dormant and growing season fire. We explored the effects of growing season fire on breeding territory vegetation characteristics. Our results indicate that burn type (dormant vs. growing season), native grass groundcover, and shrubs over 1m were the most significant predictors for wintering Bachman’s sparrow …

Tamaulipan Thornforest Restoration: Factors Influencing Restoration Outcomes And Impacts Of Cover Crops During Replanting, Jerald T. Garrett

Theses and Dissertations

Though the rate of deforestation has slowed in recent years, it remains a primary cause of land cover change within forest ecosystems. The Lower Rio Grande Valley, Texas (LRGV) has lost nearly 95% of its native thornforest since the early 1900’s due to agricultural and urban expansion. The focus of this study is to assess the current vegetative state of restored thornforest sites located in the eastern LRGV and to evaluate the use of cover crops during replanting of native seedlings. Our assessment of restored thornforest sites revealed actively restored sites demonstrated higher overall averages of richness, abundance, and diversity …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …

Synthesis Of Biomass-Based Graphene Nanomaterials For Aqueous Heavy Metal Removal And Cement-Based Composite Property Enhancement, Tharindu N. Karunaratne

Theses and Dissertations

Utilizing biomass such as lignin, bamboo, soybean, corn stalk, rice husk, etc., as a carbon source to produce graphene-based nanomaterials has been reported recently. However, the potential of using such nanomaterials for engineering and environmental applications has not been realized. This dissertation investigates the use of graphene-based nanomaterials synthesized from using biomass as a carbon source for water remediation and cement-based composites’ (CBCs) property enhancement.

The first chapter introduces graphene and graphene-based nanomaterials, as well as the synthesis and application of graphene-based nanomaterials for removing heavy metals in an aqueous solution and for property enhancement in CBCs. The experimental investigation …

Modeling Yield And Aboveground Live Tree Carbon Dynamics In Oak-Gum-Cypress Bottomland Hardwood Forests, Suchana Aryal

Theses and Dissertations

The importance of bottomland hardwood (BLH) forests to support the economy through timber production and carbon sequestration is acknowledged; however, their full potential is yet to be explored. This study developed variable density yield models for BLH oak-gum-cypress forests along the US Gulf Coast and Lower Mississippi River Delta. The models, with an adjusted R2 of 98% for cubic foot growing stock volume and 77% for Doyle board foot sawlog volume, are expected to be valuable tools for landowners and managers seeking to make informed decisions about BLH forest management.

A carbon stock model was also developed, and carbon sequestration …

The Response Of An Avian Community To Intercropping And Forest Management Practices In A Private Working Pine Forest, Rebecca Doyne Bracken

Theses and Dissertations

Within managed pine forest systems, a plethora of bird species exist throughout the lifecycle of a stand akin to what may be experienced through post-disturbance regeneration in a natural forest system. I sought to address how breeding avian communities shift across time in response to stand aging and forest management, evaluate species-specific responses to stand conditions, investigate the responses of at-risk avian species to forest management, and determine avian non-breeding, over-wintering presence in a managed loblolly pine (Pinus taeda) forest. I conducted breeding bird point count and vegetation surveys within five stands of privately owned and managed pine forest in …

Surface Modification Of Wood Using Nano-Sized Titania Particles Coated By Liquid-Precursor Flame Spray Pyrolysis, Ganesh Sedhain

Theses and Dissertations

Wood is a renewable resource and versatile material used in tasks ranging from tools and furniture to advanced engineering structures. Although wood is light, mechanically robust, environmentally friendly, and abundant, some inherent properties of wood, such as degradation due to moisture and UV radiation from sunlight, are less desirable for extended service life and dimensional stability. In this dissertation, a novel surface modification of wood is explored by depositing nano-sized titania particles on wood veneers and cross-laminated timber (CLT) blocks by liquid-precursor flame spray pyrolysis to confer reversible wettability switching and enhanced durability to UV irradiation. The reaction between a …

Expanding The Market Of Biomaterials, Franklin Quin Jr.

Theses and Dissertations

Biomaterials such as wood and bamboo are in high demand as a building material with the push for building with green technology. The wood product industry accounts for approximately 4% of the total U.S. manufacturing GDP (Gross Domestic Product), which is more than $100 billion. The industry supports over 752,000 full-time equivalent jobs, most of which are in rural areas where employment opportunities are limited. The estimated global market value of bamboo is estimated to be $60 billion annually. This research will explore the use of wood and bamboo in different end use products. The objectives of this research will …