Forest Sciences Commons^™

Disease Resistance And Productivity In Genetically Improved Loblolly Pine: Results From A Resistance Screening Trial And A Midrotation Comparison Of Genetic Improvement Levels, Stephen W. Goodfellow

Theses and Dissertations

Decades of tree improvement has resulted in genetic gains in loblolly pine productivity, form, and resistance to fusiform rust. The goal of this study was to advance the understanding and applied use of genetic improvement by analyzing inter- and intra-provenances hybrids’ rust resistance and evaluating midrotation performance of varying levels of genetically improved stock types. The first study compares 16 seedlots at the USDA Resistance Screening Center and evaluates rust resistance of controlled-pollinated inter- and intra-provenances crosses, and openpollinated seedlots from three provenances: Western Gulf, Atlantic Coastal, and Interior Piedmont. Post inoculation, one Coastal OP seedlot was resistant and ten …

Mapping Forest Structure In Mississippi Using Lidar Remote Sensing, Nitant Rai

Theses and Dissertations

This study aimed at evaluating the agreement of spaceborne Light Detection and Ranging (lidar) ICESat-2 canopy height with Airborne Laser Scanning (ALS) derived canopy height to inform about the performance of ICESat-2 canopy height metrics and understand its uncertainties and utilities. The agreement was assessed for different forest types, physiographic regions, a range of percent canopy cover, and diverse disturbance histories. Results of this study suggest that best agreements are found using strong beam data collected at night for canopy height retrieval using ICESat-2. The ICESat-2 showed great potential for estimating canopy heights, particularly in evergreen forests with high canopy …

Assessing Wood Failure In Plywood By Deep Learning/Semantic Segmentation, Ramon Ferreira Oliveira

Theses and Dissertations

The current method for estimating wood failure is highly subjective. Various techniques have been proposed to improve the current protocol, but none have succeeded. This research aims to use deep learning/semantic segmentation using SegNet architecture to estimate wood failure in four types of three-ply plywood from mechanical shear strength specimens. We trained and tested our approach on custom and commercial plywood with bio-based and phenol-formaldehyde adhesives. Shear specimens were prepared and tested. Photographs of 255 shear bonded areas were taken. Forty photographs were used to solicit visual estimates from five human evaluators, and the remaining photographs were used to train …

Vegetation And Nutritional Changes Over 20 Years Of White-Tailed Deer Exclusion, Gabrielle Nicole Ripa

Theses and Dissertations

Knowledge of the impacts of white-tailed deer (Odocoileus virginianus; hereafter deer) as dominant herbivores throughout the Southeastern United States of America is lacking. To address this, three paired experimental units of exclosures and controls were constructed in 2000 on three Wildlife Management Areas across Mississippi within the ecoregions of the Upper Coastal Plain, Lower Coastal Plain, and the Mississippi Alluvial Valley. Vegetation was sampled in the summers of 2000, 2005, and 2021 including vegetation structure, canopy coverage, basal area, and species composition. Additionally, in 2005 and 2021, biomass was sampled to determine potential impacts on nutritional carrying capacity. Among the …

Evaluating Functional Zoning Based On Site Index To Achieve Competing Objectives Held By Family Forest Owners On Southern U.S. Pine Forest Tracts, Bradley S. Resch

Theses and Dissertations

Family forests comprise a significant portion of total forest lands in the southern United States and their owners frequently have multiple, competing objectives. This research evaluated the effectiveness of functional zoning based on site index on forest sizes relevant to family forest owners. A total of fifty family forests were randomly selected from counties in the East Texas Pineywoods region. Timber production and quail habitat were used as proxies for competing objectives. It was found that 80% of family forest parcels had sufficient site index heterogeneity to benefit from functional zoning. For forest parcels that could benefit from functional zoning, …

Novel Silviculture Practices For Non-Industrial Private Forest Landowners, Darcey Alyce Collins

Theses and Dissertations

Many landowners in the southeastern United States have invested in southern yellow pine plantations and managed them using traditional management schemes. However, non-industrial private forest landowners often have goals and challenges that make traditional management less desirable or possible. This thesis contains two projects that offer potential solutions for these landowners. The first project is a management option for landowners with small parcels that wish to manage pine plantations and proposes low-density management paired with crown lifting for the production of saw logs without commercial thinning entries. The second proposes a method for incorporating mixed-species management into already existing plantations. …

Evaluation Of Flood Damage On Cross Laminated Timber Wall Configurations, Mustafa Nezih Kaya

Theses and Dissertations

Greenhouse gas emissions are one of the critical factors that affect climate change, increasing flooding risk and threatening human life. The use of traditional construction materials is responsible for a higher percentage of global greenhouse gas emissions when compared to the use of sustainable materials in the construction industry. The substitution of current building materials with sustainable materials is essential to reduce greenhouse gas emissions and positively influence climate change when the current construction demand in the world is considered. Wood is one of the primary environmentally friendly construction materials in regard to high carbon storage and low carbon emissions. …

Nondestructive Assessment Of Flexural And Tensile Properties For Southern Pine Structural Lumber, Marly Gabriela Carmona Uzcategui

Theses and Dissertations

The flexural and tensile properties of visually graded southern yellow pine lumber were modeled. Longitudinal and transverse vibration techniques and proof-loading bending tests were used to assess the flexural and tensile properties of southern pine lumber. The properties evaluated were dynamic modulus of elasticity (dMOE), static modulus of elasticity (E_b), tension modulus of elasticity (E_t), and ultimate tensile stress (UTS). The tensile properties were evaluated in the direction parallel to the grain. This study presents the results of tests conducted on No. 2 2 × 6 and 2 × 10 southern pine lumber of two different …

Improvement Value Of Forest Resources By Use Of Cottonseed Protein Meal As A Bio-Based Wood Adhesive For Hardwood Plywood Products, Edward David Entsminger

Theses and Dissertations

Literature shows that production of cottonseed adhesives is feasible to develop an environmentally friendly and competitive bio-based wood adhesive. Defatted cottonseed and water-washed cottonseed meals were prepared from glandless cottonseed and were used in adhesive formulations to produce three-ply yellow poplar (Liriodendron tulipifera) plywood panels as the first objective. These two cottonseed meals were compared with the properties of plywood panels made with an adhesive formulated from a commercial soybean meal, as a control. Adhesive resins were prepared from each protein meal with sodium metabisulfite (Na2S2O5) and one of two polyamido-amine-epichlorohydrin (PAE) wet strength agents, and the plywood panels were …

Assessing The Flood Tolerance, Physiological Mechanism, And Nutrient Mitigation Potential Of Short Rotation Woody Crops Planted On Seasonally Flooded Marginal Land Of The Lower Mississippi Alluvial Valley, Thu Ya Kyaw

Theses and Dissertations

In 2019, the Mississippi River watershed had a record-long flooding, which was comparable with the 1927 Great Mississippi River Flood. This study leveraged this flooded condition to assess the flood tolerance of eastern cottonwood (Populus deltoides) and black willow (Salix nigra) planted as short rotation woody crops (SRWCs) on seasonally flooded marginal land of the Lower Mississippi Alluvial Valley (LMAV) in 2018. The survival/mortality prediction models developed by using hydrologic and environmental variables suggested that only high flood depth affected the survival of black willow. However, eastern cottonwood was threatened by flood depth, flood duration, and …

Quantifying Aboveground Biomass In A Tropical Forest Using A Lidar Waveform Weighted Allometric Model, Alejandro Rojas

Theses and Dissertations

Our knowledge of the distribution and amount of terrestrial above ground biomass (AGB) has increased using lidar technology. Recent advancements in satellite lidar has enabled global mapping of forest biomass and structure. However, there are large biases in satellite lidar estimates which impacts our understanding of carbon dynamics, particularly in tropical forests.

Ni-Meister et al. (2022) developed a lidar full waveform weighted height-based allometric model which produced very good results in temperate deciduous/conifer forest in the continental US. The purpose of this study was to evaluate this biomass model in an African tropical forest using the Land Vegetation and Ice …

Quantifying And Predicting Drought Performance In Woody Semi-Arid Seedlings In South Texas: Implications For Enhancing Drought Resilience In Restoration, Zarek Contreras

Theses and Dissertations

Increasingly frequent and severe droughts in the Lower Rio Grande Valley National Wildlife Refuge have been observed to cause large variation in species-specific mortality patterns in young seedlings, spanning 6 – 43 % mortality within the first year. To understand the underlying mechanisms behind this, we subjected seedlings of five woody semi-arid species (Celtis pallida, Forestiera angustifolia, Sideroxylon celastrinum, Phaulothalmnus spinescens, and Zanthoxylum fagara) to a point-of-no-return drought experiment in order to (1) identify potential metrics capable of predicting species wilting and mortality responses, and (2) to understand the underlying mechanisms that correspond to species drought performance …

Diversity-Productivity Relationships In Forests Of The Southeastern United States: Leveraging National Inventory Data And Tree Functional Traits, Elizabeth Baach

Theses and Dissertations

Numerous studies have evaluated the relationship between biodiversity and productivity, with general trends suggesting a positive relationship. While most studies only use species richness, this study also analyzed how productivity changes with functional diversity and Shannon’s diversity index. Functional diversity gives important context to the examination of biodiversity-productivity relationships due to the direct link between organisms’ functional traits and their role in a given ecosystem. This study used data from the USDA Forest Service Forest Inventory and Analysis (FIA) database collected in Alabama, Louisiana, and Mississippi to estimate plot-level productivity and diversity. Structural equation modeling was used to determine the …

Use Of Consumer Grade Small Unmanned Aerial Systems (Suas) For Mapping Storm Damage In Forested Environments, James Dewey Cox

Theses and Dissertations

Storm damages to forested environments pose significant challenges to landowners, land managers, and conservationists alike. Damage scope and scale assessments can be difficult, costly, and time consuming with conventional pedestrian survey techniques. Consumer grade sUAS technology offers an efficient, cost-effective way to accurately assess storm damage in small to moderate sized survey areas (less than 10 km²). Data were collected over a 0.195 km² area of damaged timber within the Kisatchie National Forest in Central Louisiana using a DJI Mavic 2 Pro drone. Collected imagery was processed into an orthomosaic using Agisoft Metashape Professional with a resulting ground sampling distance …

Determination Of Flexural Strength Of Structural Red And White Oak And Hardwood Composite Lumber, Alan Sherrington

Theses and Dissertations

In this research, flexural properties of mill-run, in-grade white oak and red oak lumber from a single mill and commercially available laminated hardwood composite were evaluated. Structurally graded green (wet) freshly sawn red oak and white oak 5 by 10-cm (2 by 4-in.) nominal lumber as well as glue-laminated hardwood composite billets were tested in bending and their modulus of rupture (MOR) and modulus of elasticity (MOE) properties were developed. It is well documented that MOR and MOE are two major indicators to evaluate flexural strength of wood lumbers. From these data, summary statistics, design values, and mean separations were …

Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro

Theses and Dissertations

Fire suppression, combined with lack of forest thinning and short-rotation, monodominant management, has drastically altered the landscape in the southeastern U.S., leading to the loss of open pine ecosystems and associated avian species. Management of open pine ecosystems is a common practice; yet, there remains uncertainty regarding how vegetation structure impacts priority species. Using empirical data, I assessed changes in species abundance and associated vegetation characteristics before and after management. I also sought to identify vegetation characteristics that influence home range establishment and microhabitat selection of Bachman’s Sparrows. Priority species were negatively associated with hardwood midstory and abundance per site …

Cross-Laminated Timber (Clt) Mechanical Properties Evaluation., Laurice Mara Spinelli Correa

Theses and Dissertations

As the use of engineered wood products as such as cross-laminated timber (CLT) evolves in United States, it’s imperative to understand its behavior under different circumstances as well as to explore new possible streams for product’s application. In that matter, it was proposed that a research study would be developed to evaluate the performance of CLT panels focusing on strength and stiffness properties. To accomplish this goal, three main objectives were traced: 1) To complete preliminary test on traditional lumber in order to observe notched wood failure behavior focusing on strength, ductility, and failure mode; 2) To perform mechanical testing …

Climate Sensitive Diameter Growth Models For Major Tree Species In Mississippi, Sujan Subedi

Theses and Dissertations

Anticipated climate change and increasing wood demand require dependable diameter growth models for adaptive forest management. We used a mixed-effects modeling approach with Forest Inventory and Analysis (FIA) data to fit diameter growth models for loblolly pine, other softwood species (slash pine, shortleaf pine, and longleaf pine), sweetgum, and other hardwood (southern red oak, red maple, and water oak) species. Climatic variables coupled with individual tree attributes and competition factors improved climate insensitive models. Growth of loblolly pine and sweetgum was positively correlated with mean temperature of the coldest month. Mean temperature of the warmest month negatively influenced diameter growth …

Consumer Attitudes And Perceptions Towards The Use Of Reclaimed Wood, Mia Craig

Theses and Dissertations

Reclaimed wood is material salvaged from old, abandoned buildings that offers sustainable living to communities. There have been previous studies on reclaimed wood, but a limited amount linking reclaimed wood to consumerism. In August 2021, an online survey was conducted to gauge consumers’ knowledge of the industry and attitudes on reclaimed wood practices. Consumers are U.S. citizens 18 years of age or older. Study results indicate that respondents have little knowledge regarding reclaimed wood. Of the 1,516 respondents, 44% seem knowledgeable of reclaimed wood. Most respondents are not aware that reclaimed wood is a separate industry. Respondents believe there should …

Attitudes And Perceptions Of College Students And Recent College Graduates Towards Forestry And Wood Products Science Fields, Amanda Peres Vieira Bedette

Theses and Dissertations

Over the past few decades, university level US Forestry and Wood Science and Technology programs have faced declining enrollment. As a result, the seeming disinterest of younger generations has impacted employment in these sectors. In an attempt to bridge the communication gap among colleges/industries, this study was created to attract the interest and maintain the enthusiasm of new generations of professionals and currently enrolled college students in the United States. In September 2021, an online survey was created and distributed to over 1500 alumni and students and received 1,495 usable surveys. Analysis performed on the resultant data included descriptive statistics …

Enhancing The Performance Of Dowel Type Fasteners And A Case Study Of Timber Truss Failure, Lon A. Yeary

Theses and Dissertations

This document will outline the findings of three separate and independent studies: Study 1: In or around 1972, an experimental building was constructed. One of the intents of the construction project was to demonstrate advancements in wood building construction design. It was value-engineered throughout. That is, its materials and systems were intended to function at or near design capacity. In 2019, part of the roof of the structure collapsed. This case study investigates two potential factors that led to the failure: stress concentration in excess of the 12 allowable stress for 2 × 4 web members and insufficient plywood sheathing …

Wood Properties And Utilization Of Assorted Hardwoods, Roger Dustin Snow

Theses and Dissertations

This work is made up of three parts. Part one looks to establish design values for two types of three ply access mats from the U.S. South and Midwest. The mats were subject to 3 point bending tests to determine strength and stiffness values. Values for MOE (Modulus of Elasticity) and MOR (Modulus of Rupture) are reported by region and mat design. Part two tested five species groups of hardwoods for wear resistance and hardness. These species groups include white oak, red oak, ash, sweetgum and hickory. These tests for wear were performed on a Navy-Type Wear Tester according to …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …