Digital Commons Network^™

Education And Land Management On The Pacific Crest Trail Phase 4, Ben Sherman, Emma Perry, Cade Cappello, Hattie Cahill, Anna Macklyn, Aidan Tull, Tristian Xu, Augrey Gregg

Baker/Koob Endowments Awarded Projects

This research is a continuation of research collected on the Pacific Crest Trail (PCT). The purpose of this study was to investigate land ethics and education, Leave No Trace principles, and hiker experiences on the PCT. From July 2023-January 2024, interdisciplinary students collected qualitative and quantitative data through interviews and surveys with hikers on the trail. Past phases of this project have determined that this research is necessary, but due to Covid, the team has only been able to gather data remotely via online surveys and interviews prior to this study. The Baker Koob grant funded travel and research equipment …

An Evaluation Of Sonderegger Pine Morphology, Kelsey Denise Shoemaker

Master's Theses

Sonderegger pine (Pinus x sondereggeri H.H. Chapm.), the naturally occurring hybrid of longleaf (Pinus palustris Mill.) and loblolly pine (Pinus taeda L.), is considered a producer of poor-quality wood due to observations of stem forking and a high number of large-diameter branches at maturity. Because landowners generally decline planting Sonderegger pine seedlings, nursery workers cull putative hybrids from longleaf pine seedling stock during lifting and processing. However, over the past 100 years, very few studies have quantified stem quality of Sonderegger pine. To gain a better understanding of the early growth and development of Sonderegger pine, evaluations of height, diameter …

Managing The Environmental And Socio-Economic Impacts Of Rohingya Refugees In Bangladesh, Mousume Azad

Master's Projects and Capstones

In August 2017, nearly 1 million Rohingya people fled to Bangladesh to save their lives from the genocide inflicted by the military of Myanmar. At present, over 1.3 million Rohingyas are staying at Cox’s Bazar, Bangladesh, in 34 overcrowded refugee camps. This research examined the environmental impacts especially the change in vegetation cover and land surface temperature as well as the socioeconomic alteration of the host country after the refugee influx. The research found a 5488 ha or 9.58% decrease in forest area, accompanied by an 8.25% increase in refugee settlement areas, an increase in average land surface temperature within …

New York City’S Rising Sea Level And Coastal Erosion: Approaches To Resiliency, Ryder D. Isidro

Student Theses 2015-Present

No abstract provided.

Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton

All Graduate Theses and Dissertations, Fall 2023 to Present

Polyploidy is common among plants and can contribute to physiological and morphological differences, altering how plants respond to environmental changes, promoting genetic diversification and even species radiation. Quaking aspen (Populus tremuloides), a keystone species associated with high plant and animal diversity is frequently found in mixed diploid/triploid populations in the Intermountain West. Triploid aspen carries an extra chromosomal copy, whereas the diploid type contains two chromosomal copies. High mortality rates and widespread population declines in aspen are of increasing concern in the Intermountain West, and often ascribed to changing climates and drought stress events. The goal of this …

Assessing Equitable Distribution Of The Urban Tree Canopy At The Neighborhood Scale In Greenville, South Carolina., April Riehm

All Theses

We are living in an era that necessitates adaptation and resilience. The Earth is warming. Our climate has changed (EPA, 2016). Our planet is also rapidly urbanizing. It is predicted that 68% of people will live in cities by 2050. The City of Greenville is a rapidly growing city in South Carolina that has been losing its tree canopy to development(City of Greenville, 2023). The Urban Tree Canopy (UTC) is a community asset that provides many quality-of-life benefits including improved air quality, stormwater management, carbon sequestration, mental and physical well-being, increased mobility and access, aesthetics, a reduction in energy costs, …

An Evaluation Of Potential Biocontrol Agents For Anoplophora Glabripennis (Coleoptera: Cerambycidae) In South Carolina, U.S.A., Marina Lupu

All Theses

The Asian longhorned beetle (Anoplophora glabripennis Motschulsky, hereafter ALB) was named one of the world’s top 100 worst invasive species by the Global Invasive Species Database, as it threatens several species of hardwood trees in North America. In May of 2020, the southernmost infestation of ALB in North America was discovered near Hollywood, South Carolina, U.S.A. Current eradication efforts focus on tree removal; however, in ecosystems with rugged or flooded terrain, or otherwise inaccessible and vulnerable natural areas, tree removal is a costly and potentially environmentally damaging endeavor that may not be feasible as a management tactic. In these …

Winter Roost Selection Of Eastern Red Bats And Impacts Of Non-Growing Season Prescribed Fire On Foraging Activity Of Forest Roosting Bats In Tennessee, Ashley D. Epstein

Masters Theses

With an increase in wind energy development and continued deforestation and habitat degradation, eastern red bats (Lasiurus borealis; LABO) and other migratory foliage roosting bats (hoary bat [Lasiurus cinereus; LACI], silver-haired bat [Lasionycteris noctivagans; LANO]) are at risk of severe population declines, potentially leading to the need for protection under the Endangered Species Act. While studies have been done examining the ecology of these species, there is still a lack of research on winter roosting and foraging behaviors. This research aims to fill some of those knowledge gaps by 1) Examining roost use (i.e., trees vs. litter) …

Tree Canopy Cover Influences Habitat Use Of Breeding Birds At Jack Mountain Wildlife Management Area, Kaleigh Thomas

Honors Theses

Across the United States, bird populations have declined due to habitat loss. To better understand habitat use by birds, researchers observed populations at Jack Mountain Wildlife Management Area in southwest Arkansas. Students at Ouachita Baptist University surveyed 94 point count locations to estimate species diversity (total number of species observed) and species abundance (total number of individuals observed). At each point, students recorded the percentage of tree canopy cover, ground cover, midstory cover, and shrub cover. These variables were used as explanatory variables in multiple regression analyses to determine which variables were influential in explaining variation in species diversity and …

A Ground-Based L-Band Radar System For Monitoring Forest Temporal Dynamics, Xingjian Chen

Doctoral Dissertations

L-band FMCW radar is implemented for monitoring forest dynamics. It took short-term and long-term measurements with an internal calibration system that guarantees stability and precision. The radar data is compared to in-situ measurement, which infers causal relationships between radar backscatter signal and forest physiology index such as tree dielectric. This paper explains the relationship between radar signals and environmental components such as precipitation based on the measurement. The radar demonstrates some interesting observations, for example, trees' daily activity and freeze-thaw process.

Design And Test The Effectiveness Of Interpretive Signs Using Eye Tracking And Biometric Data, Hadara Gordon, Wendy Miyazaki

Baker/Koob Endowments Awarded Projects

Recreational trails on forested lands should satisfy the needs of recreationists, safeguard important habitats, and maintain the natural environment (Kortenkamp et al., 2021). Appropriate management is critical because of the increasing number of visitors. Signs are a cost-effective method to reduce the negative impacts on visitors and enhance visitor experiences (Brown et al., 2010). This research aimed to investigate how visitors pay attention to signs, view the trail surrounded by trees and behave in a natural space.

Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins

Master's Theses

Understanding the dynamic interplay between fire severity, topography, and tree mortality, is crucial for predicting future forest dynamics and enhancing resilience against climate change-induced wildfire regimes. This thesis develops a multi-sensor approach for automated estimation of tree mortality, then applies it to examine trends in tree mortality over a six-year period across a fire affected study site in the Trinity River basin in Northern California. The Random Forest model uses publicly available USGS 3D Elevation Program Lidar (3DEP) and NAIP imagery as inputs and is likely to be easily adaptable to other landscapes. The model had a Receiver Operating Characteristic …

Development And Application Of Functional Immune Assays To Understand Disease In Wild Smallmouth Bass Populations, Cheyenne R. Smith

Graduate Theses, Dissertations, and Problem Reports

Over recent decades, the scientific community has observed a disconcerting trend – a decline in the health and stability of smallmouth bass (Micropterus dolomieu) populations across the Chesapeake Bay watershed with growing economic and ecological implications. Disease, declines, and death have been observed in multiple locations, particularly in the Susquehanna and Potomac drainages with the adults disproportionately affected in the Potomac River basin and young-of-year in the Susquehanna River basin. There has not been a single or consistent cause to the declines or mortality events. More likely, it is believed immunosuppression relating to a complex mixture of stressors has been …

Investigating Birds As Dispersal Vectors Of Litylenchus Crenatae Subsp. Mccannii (Anguinidae), The Nematode Associated With Beech Leaf Disease, Spencer Rock Parkinson

Graduate Theses, Dissertations, and Problem Reports

Beech leaf disease (BLD) is an emerging forest pathogen primarily affecting American beech (Fagus grandifolia, Ehrh.) in North America and has been attributed to tree mortality of sapling sized trees within five to seven years of infection. Symptoms typically occur in regenerating American beech thickets sprouting from roots of trees killed by beech bark disease. Scientists first observed BLD in Ohio in 2012 and currently has spread to 15 states in the USA and one Canadian province. The nematode Litylenchus crenatae subsp. mccannii (Lcm) is highly associated with BLD symptoms, interveinal chlorosis and defoliation of leaves, and is currently …

Bioenergy Cropping Systems Established On Marginal Lands: Effects Of Land Use, Energy Crop, And Fertility Amendments On Soil Health, Mica M. Keck

Graduate Theses, Dissertations, and Problem Reports

Bioenergy crops offer a promising strategy for renewable energy production, accompanied by carbon (C) storage benefits when managed sustainably. Utilizing marginal lands for energy feedstock production presents an opportunity for bioenergy generation and concurrent climate mitigation without competing with food crops. However, achieving optimal yields requires strategies to restore soil fertility, which require increased understanding of the interactive effects of prior land use, energy crop species, and fertility amendments available. This study, conducted as part of the Mid-Atlantic Sustainable Biomass (MASBio) Consortium, investigated the effects of biochar incorporation—a C-rich charcoal derived from biomass, intended for soil enhancement—on bioenergy cropping systems …

Predicting Leucotaraxis Spp. Adult Emergence In The Pacific Northwest With Implications For Biological Control Of Hemlock Woolly Adelgid In The Eastern United States, Liam Farley

Graduate College Dissertations and Theses

Hemlock woolly adelgid (Adelges tsugae) is a non-native, invasive pest of eastern hemlock (Tsugae canadensis) and Carolina hemlock (Tsugae caroliniana), both of which are considered important foundation species in forest ecosystems. Adelges tsugae has caused widespread decline and mortality of hemlock trees in eastern North America. Native hemlocks are particularly vulnerable because of the absence of co-evolved plant defenses and lack of natural enemies of A. tsugae. Managing A. tsugae through development of a biological control program has great potential at the regional level. Two species of silver fly from the Pacific northwest (PNW) Leucotaraxis argenticollis and Leucotaraxis piniperda are …

Longevity Of Prescribed Fire Effectiveness In Mixed-Evergreen Forests Of The Klamath Mountains, Kaily M. Fineran

Cal Poly Humboldt theses and projects

Prescribed fire is a common management tool used across the western United States to create wildfire-resilient ecosystems and communities. The Klamath Mountains of northern California, USA has experienced numerous, large wildfires in recent years. This is due in part to a combination of highly flammable fuels, uncharacteristic weather events, and high fuel accumulations as a result of fire exclusion and forest management practices. Within the last decade, local land management organizations and the Karuk Tribe have begun re-introducing prescribed fire in low elevation, mixed evergreen forests. While the long-term effects of fuel treatments are not well-known, these efforts provided a …

Post-Fire Persistance Of Sequoia Semperviens In A Secondary Forest: Examining Drivers Of Basal Resprouting Response, Jackson T. Carrasco

Cal Poly Humboldt theses and projects

Historically frequent-fire forest ecosystems are now facing increased size, frequency, and severity of fires attributed to climate change, intensive forest management, and fire exclusion. Understanding post-fire resilience in forest ecosystems is critical amidst escalating challenges posed by recent increases in fire activity. This study examined the basal resprouting response of coast redwood (Sequoia sempervirens) in a secondary forest two years after the CZU Lightning Complex fire on the central coast of California. Robust allometric equations were developed to quantify redwood resprout biomass and leaf area, revealing strong explanatory power for biomass equations (R² > 0.85). Probability of …

Environmental Implications Of Modern Food Production: An Analysis For The Conscious Consumer, Jessica T. Coming

Cal Poly Humboldt theses and projects

This project explores the pathways by which agriculture affects the environment and determines which foods have the greatest climate, water, and land impacts. Agricultural effects on the environment are extensive, from loss of habitat and declines in regional biodiversity to disruption of global nutrient cycles and climate change. Global food production accounts for 26-34% of annual anthropogenic greenhouse gas emissions, makes up 38-46% of habitable land, and is responsible for 70% of freshwater extraction. The effect of agriculture on the environment is most significantly dictated by what type of food is being produced. Animal-based food products consistently have the highest …

Determining The Quality And Quantity Of California Sitka Spruce (Picea Sitchensis) On Private Commercial Timberland For Use In Domestic Acoustic Steel-String Guitars, Ryan Eugene Cooper

Cal Poly Humboldt Capstone Honor Roll

Development of additional revenue streams for timber products with relatively low profitability is an important step in securing future economic success for the forestry sector in Humboldt county. Utilization of California Sitka spruce (Picea sitchensis) for use in domestic acoustic steel-string guitar manufacturing may provide exactly that. Determining the quality and quantity of California Sitka spruce is the logical first step in achieving this.

Quality was determined from tree core samples gathered at sites on Green Diamond Resource Company’s (GDRco) California timberlands and the Arcata Community Forest (ACF) with high basal area of Sitka spruce. Rings Per Inch …

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …

A Conservation Model: Costa Rican Conservation Strategies Effectively Preserve Their Threatened Primates, Ryan Belmont

Regis University Student Publications (comprehensive collection)

The wildlife of Costa Rica has experienced various anthropogenic threats over the last century including climate change and agricultural expansion. The mantled howler monkey (Alloutta palliata), Central American spider monkey (Ateles geoffroyi), white-faced capuchin (Cebus imitator), and the Central American squirrel monkey (Saimiri oerstedii) are Costa Rica’s native primates that face several anthropogenic threats such as deforestation for agriculture and climate change. In response to increased threats to its four native species of non-human primates, Costa Rica has implemented effective governmental conservation tactics such as the Payments for Environmental Services program, ecotourism …

Environmental Biology Masters Capstone, Antonio Gonzalez-Pita

Regis University Student Publications (comprehensive collection)

Human wildlife interactions (HWI) pose a complex challenge for wildlife managers. Human encroachment into wildlife habitat and the growing number of outdoor recreationists are increasing the frequency of contact and conflict, especially in regions such as the Front Range of Colorado. Geographic information systems (GIS), which use a combination of remote sensing and environmental survey data, allow for predictive spatial analyses of where human wildlife interactions are likely to occur. I used publicly reported observations of moose to create spatial predictive maps in a species distribution model framework. Slope and elevation were shown to be the strongest predictors of HWI, …

Movement Behavior And Metapopulation Connectivity Of Stream Salamanders In Response To Disturbance Events, Kathryn M. Greene

Theses and Dissertations--Biology

Metapopulations are shaped by the dispersal between populations in a landscape. Disturbance events can disrupt this connectivity resulting in local population extinction. For my dissertation, I used a combination of empirical and theoretical techniques to examine dispersal in response to disturbance and assessed it’s population-level consequences. My research used capture-mark-recapture sampling techniques to evaluate stream salamander movement in response to (1) a supraseasonal drought and (2) mountaintop-removal-mining (MTR) and valley-filling (VF) and (3) agent-based simulation modeling to evaluate population extinction risk in response to varying dispersal and mortality rates.

First, I evaluated the effects of a supraseasonal drought, a severe …

Developing Novel Food Packaging Products With High Barrier Properties, Enabled By Cnf, Nabanita Das

Electronic Theses and Dissertations

In recent times, plastic has become a highly favored choice for packaging due to its exceptional microbial, damage, and water-resistant properties. However, the alarming rise in plastic usage has led to adverse environmental pollution. This study aims to develop innovative food packaging solutions using renewable and compostable cellulose nanofibrils (CNFs). This thesis comprises two related studies on the barrier performance of novel food packaging materials, including oxygen barrier and oil/grease barrier properties. The goal of the first study was to enhance the mechanical and barrier properties of the cellulose nanofibril (CNF) films by inducing fibrils orientation for food packaging applications. …

Regeneration Response To Salvage Logging Following Tornado Disturbance, Colby K. Bosley-Smith

Electronic Theses and Dissertations

In an era of increasing natural disturbances, successful tree regeneration has grown more difficult to achieve. Salvage logging, a common management response to disturbance, may further impede regeneration success, although published literature currently remains inconclusive. In 2013, a rare tornado in northcentral Maine, USA, and subsequent salvage operation created three clear ‘treatments’ for evaluation of post-disturbance regeneration: blowdown, blowdown followed by salvage logging and an undisturbed control. In the summers of 2022 and 2023, (nine and ten) years post-tornado, we revisited this site to examine regeneration outcomes.

During the summer of 2022, we evaluated stand structure and regeneration success of …

Integrating Remote Sensing And Machine Learning To Assess Forest Health And Susceptibility To Pest-Induced Damage, Rajeev Bhattarai

Electronic Theses and Dissertations

Spruce budworm (Choristoneura fumiferana; SBW) outbreaks are cyclically occurring phenomena in the northeastern USA and neighboring Canadian provinces. These outbreaks are often of landscape level causing impaired growth and mortality of the host species namely spruce (Picea sp.) and balsam fir (Abies balsamea (L.) Mill.). Acknowledging the recent SBW outbreak in Canadian provinces like Quebec and New Brunswick neighboring the state of Maine, our study devised comprehensive techniques to assess the susceptibility of Maine forests to SBW attack. This study aims to harness the power of remote sensing data and machine learning algorithms to model and map the susceptibility of …

Forest Management In A Changing Climate: Integrating Social And Biopysical Sciences To Inform Adaptive Responses To Future Uncertainty, Peter Breigenzer

Electronic Theses and Dissertations

Forests provide numerous ecological and socio-economic benefits, yet climate change is creating novel and extreme conditions that threaten forests and disrupt traditional management practices. To address future uncertainty about how to manage forests amid a rapidly changing climate, researchers have developed adaptive management strategies that move away from using historical ecological baselines as management goals. However, despite increases in adaptive forest management frameworks, there are still concerns that private woodland owners (PWOs; also known as family forest owners or non-industrial private landowners) are not adopting beneficial practices. Additionally, since tree canopies often buffer understory microclimates (i.e., fine scale variation in …

Mobilizing Indigenous Research Methodologies And Wabanaki Knowledge In Biophysical Research To Restore Wabanaki Sweetgrass Harvesting In Acadia National Park And Identify Basket Quality Black Ash Habitat For Emerald Ash Borer (Agrilus Planipennis) Preparedness, Suzanne Greenlaw

Electronic Theses and Dissertations

Black ash (wikpiyik/Fraxinus nigra) and sweetgrass (suwitokolasol/Anthoxanthum nitens) are two culturally important species to Wabanaki (Passamaquoddy, Penobscot, Maliseet, Mi’kmaq, and Abenaki) people, and to many other Native American tribes across the species’ ranges. Wabanaki relationships with black ash and sweetgrass include creation stories, generational stewardship practices, important economic markets, and cultural identity. Land use patterns, changes in access, invasive species, and climate change are negatively affecting both the health of black ash and sweetgrass and Wabanaki people’s relationship to these species. This dissertation consists of five chapters that mobilize Wabanaki knowledge and address Wabanaki access to sweetgrass and an invasive …

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 …