Forest Sciences Commons^™

Wildfire And Fuel Treatments In Utah: A Practical Guide And Outcomes From An Oak-Maple Ecosystem, Annie E. Prescott

All Graduate Theses and Dissertations, Fall 2023 to Present

Wildfire is a natural part of Utah’s landscapes, but as wildfires become more extreme and communities continue to expand into wildland areas, it is increasingly important to understand how wildfires behave and how their negative effects can be mitigated. One way to reduce wildfire risks and protect life, property, and ecosystem services is through fuel treatments — actions that reduce the amount and arrangement of flammable vegetation through mechanical removal, wildland fire, or other methods.

Information on wildfire behavior and fuel treatments is abundant but often scattered, ecosystem-specific and difficult to access. In addition, most research in the Western U.S. …

Exploring The Effects Of Pest-Induced Hemlock Mortality On Growth In Neighboring Trees, Sidney L. Booher

McNair Culminating Research Projects

Trees provide many important products and services to humans. In particular, tree growth is critical to carbon storage, air and water quality, and helps determine demographic processes like population growth and reproductive success. Importantly, tree growth is sensitive to both abiotic (environmental) and biotic factors and is vulnerable to ecological disturbances. Understanding how tree populations respond to disturbances, like invasive pests, is therefore crucial to formulating timely and effective forest management practices.

Here, I used tree ring analysis to investigate how competition for water between neighboring trees changes following the decline of Eastern and Carolina Hemlock(ECH) trees due to the …

Deforestation Dynamics In The Amazon: Impacts, Socio-Environmental Drivers And Restoration Pathways, Maria Natalia Rodriguez

Master's Projects and Capstones

The Amazon, which is the largest tropical rainforest in the world, experienced 542,581 km² of forest loss between the years 2000 and 2020. The process of deforestation endangers the ecological system results which maintain ecosystem connectivity and the Earth's climate system. The Amazon rainforest supplies essential ecological services which include maintaining soil fertility, storing carbon, purifying water and climate stability. The fundamental ecosystem of this area faces new threats because of increasing forest destruction. The research study adopts a combined methodology that uses Geographic Information Systems (GIS) with a comprehensive literature review to study Amazon deforestation patterns and its driving …

Watershed Amendments: Assembling New Pervious Ground From Landscape Waste, Sophie Kaplan-Bucciarelli

Masters Theses

In Providence, Rhode Island, much of the downtown area is built over a vast historic tidal estuary. Though we no longer see the salt marshes, wooded bluffs, or meadows that once characterized this landscape, we recognize their absence in contemporary crises of urban heat, flooding, polluted soils and stormwater runoff, and habitat loss. These conditions are particularly acute along the city’s industrialized river corridors, where vacant lots and parking areas sit idle, their history paved over and potential constrained by limited imagination and resources.

These lots - already experiments in fill and land building after centuries of disturbance - can …

Dendroclimatic Response Of The Wet Miombo Woodland Species: A Case Study Of Mufulira District, Copperbelt Province, Zambia, Collins Chibuye Malubeni

All-Inclusive List of Electronic Theses and Dissertations

Zambia is a tropical, landlocked country that lies in the South-Central part of Africa. The climate in Zambia includes distinct dry and rainy seasons, mainly influenced by the north-south movement of the Intertropical Convergence Zone (ITCZ), which shifts seasonally. This research is focused on understanding the relationship between tree growth and climate using dendrochronology. Forty-nine tropical species, including Julbernardia paniculata, Brachystegia longifolia, and Pericopsis angolensis, were analysed for dendroclimatic potential, and 70% showed clear ring formation, indicating that trees in this locality produce distinct annual ring boundaries. For the single species chronology, thirteen cores from eight trees that were initially …

Forest Overstory Mortality & Recruitment Patterns Eight Years Following Wildfire In The Southern Appalachians, Ruth Cumberland

All Theses

In this study, we investigated patterns of forest overstory mortality and recruitment eight years after wildfire in a large wildfire site the Southern Appalachians, a topic that has not been thoroughly investigated to date. With evidence that pre-fire drought promotes post-fire mortality through impaired physiological function and increased fuel consumption, unknown patterns following wildfire are important to study under shifting climate and land-use conditions. In Chapter 1, three areas of interest were investigated: (a) functional group mortality response to wildfire effects, (b) temporal differences in early (1-3 years) and late (5-8 years) periods of delayed forest overstory mortality patterns following …

Micro-Solar Kiln Design: A Cost-Effective Approach For Small Landowners To Produce Higher Quality Lumber, Bart Swecker

All Theses

Small-scale and hobby sawmill operators increasingly seek low-cost methods for drying lumber to moisture contents suitable for interior use, yet conventional kiln systems are often impractical due to capital cost, power requirements, and operational complexity. While air drying remains common at small scales, many operators require a controlled finishing step to improve dimensional stability and product value. Solar kilns offer an intermediate solution between air drying and conventional kilns; however, most published designs and performance data focus on systems with capacities far larger than those typically used by small-scale operators. Consequently, limited guidance exists for micro-scale solar kilns, particularly under …

Biology, Ecology And Control Of Eye Gnats In An Open Pine Ecosystem, Leela Hospach

All Theses

Eye gnats of the genus Liohippelates are bothersome flies of the family Chloropidae. They breed in moist, disturbed, sandy soils that contain organic matter, and have been implicated as vectors of conjunctivitis, bovine mastitis, and yaws. We conducted research into some basic biological and ecological characteristics. Using wild-caught gnats in a temperature-controlled incubator, we found that their activity peaks between 27°C and 41°C. Trapping at different heights above the forest floor in an open-pine savannah, we captured most gnats at 7.5 m off the ground. This may have to do with the attractiveness of the rotten egg lures we used, …

Diffuse Radiation Controls On Southern Pine Forest Ecosystem Functioning, Jeremy Forsythe

All Dissertations

Diffuse solar radiation, sunlight scattered by atmospheric aerosols and/or clouds, enhances plant photosynthesis through the diffuse fertilization effect (DFE), increasing ecosystem gross primary productivity (GPP) per unit of incoming radiation. Despite this known effect, pine forests of the southeastern United States remain comparatively understudied in the diffuse light literature. This is a critical knowledge gap, as the southeastern United States sequesters more carbon than any other region of the conterminous country (approximately 176 ± 26 Tg C yr⁻¹, or roughly 56% of national forest net carbon exchange), and the region experiences some of the highest biogenic aerosol loads in North …

Integrating Incentive Design And Spatial Prioritization For Climate-Smart Forestry Adoption In South Carolina, United States, Miah Maye Pormon

All Dissertations

Forests provide essential ecosystem services, including carbon sequestration, water regulation, timber production, and habitat provision. However, increasing development pressures and land-use changes threaten forest persistence and long-run ecosystem service provision. Climate-smart forestry (CSF) practices, such as improved forest management and extended rotation, offer opportunities to enhance carbon storage, forest resilience, and economic livelihoods. The effectiveness of these practices depends on forest owners’ participation and the strategic allocation of financial resources or incentives. This dissertation develops an integrated framework that combines behavioral economic analysis and mapping to improve the design of current incentive programs. The first chapter employs the Contingent Valuation …

Impacts Of Biodiversity In Short Rotation Woody Crop Production Systems On Water Quality, Nyla C. Jones

Honors Theses

Mitigating agricultural nutrient runoff and improving water quality are key challenges in meeting food and energy demands. To address this challenge, short rotation woody crops (SRWC), specifically Populus deltoides (eastern cottonwood) and its genotypes, can be planted at the interface of riparian areas and agricultural production fields to alleviate fertilizer runoff into adjacent bodies of water. This research employed an experimental design to evaluate the effects of P. deltoides diversity on tree productivity and nutrient uptake, and how it mitigates agricultural runoff. Ion exchange resins were deployed 0.5 meters below the soil surface at three different sites in Mississippi, each …

Investigating The Cost And Efficiency Of Two Chemical Pathways To Produce The Plant-Based Coagulants, Taylor Nixon

Honors Theses

Plant-based coagulants are promising sustainable alternatives for water treatment due to their biodegradability, low toxicity, and reduced risk of secondary pollution. Unlike conventional inorganic coagulants, they generate less sludge and avoid secondary contamination in the environment. This project examines two chemical modification strategies for producing cationic cellulose coagulants. The first involves direct amination of cellulose using CHPTAC, while the second employs periodate-oxidized dialdehyde cellulose, which enables reductive amination through reactive aldehyde groups. These approaches are expected to yield materials with differing charges, surface functionalities, and structural properties that may influence coagulation performance. The study evaluates the technical and economic feasibility …

Development Of A Grease Resistant Barrier For Food Industry Applications, Mira Marino

Honors Theses

The objective of this project is to develop a grease-resistant barrier coating for paper-based food packaging and to evaluate the economic feasibility of implementing this coating system at an industrial scale. As demand increases, this project focuses on identifying an optimal pigment and binder combination that enhances barrier performance while maintaining cost-effectiveness. The primary goal was to maximize grease and moisture resistance of coated paper while ensuring the process is economically viable and compatible with existing paper mill operations.

The final plant design consists of one continuous stirred tank reactor (CSTR) and three centrifugal pumps integrated into an existing paper …

Testing The Intermediate Disturbance Hypothesis On Anthropogenic Pressure In Central Alabama, Gavin Terrell

Theses

Biodiversity is fundamental to maintaining ecosystem structure and function globally. Prior to the late 20th century, ecological theory generally predicted that biodiversity would be highest in systems experiencing minimal disturbance. However, Joseph H. Connell challenged this view with the Intermediate Disturbance Hypothesis (IDH), which posits that species diversity peaks at intermediate levels of disturbance and declines under conditions of both low and high disturbance. Although widely cited, the applicability of the IDH to natural systems remains debated, particularly in the context of anthropogenic disturbances and when diversity is measured beyond species richness alone.

This study evaluated the predictions of the …

Evaluating Benthic Macroinvertebrate Communities In Streamside Management Zones In Private, Working Forests, Haley Vaglienti

College of Graduate Studies: Theses & Dissertations

Forestry operations can alter riparian vegetation and increase sediment and nutrient inputs to streams, affecting water quality and aquatic biota. Forestry best management practices (BMPs) including streamside management zones (SMZs) are designed to mitigate those effects by reducing sediment delivery and moderating temperature, flow, and nutrient regimes. We assessed ecological integrity at 24 intermittent stream sites with SMZs in private, working forests across the Piedmont and Southeastern plains of Georgia. At each site, we conducted physical habitat evaluations and characterized benthic macroinvertebrate assemblages. Sites represented a gradient of habitat conditions, SMZ widths, and pine stand ages, allowing for comparisons of …

Factors Influencing Tree Vigor And Structural Failure Along Powerline Corridors In Northern California: A Multi-Species Analysis, David Justin Dorval

Cal Poly Humboldt theses and projects

Tree failures (e.g., stem breakage, uprooting, or branch drop) can pose significant risks to public safety, particularly along powerline corridors for the risk of power outages and wildfire ignitions. In California, tree-related powerline failures have led to severe ecological and human costs in recent years. Despite extensive research on tree failure in urban environments and post-disturbance contexts, comparatively little empirical work has examined where powerlines intersect largely unmanaged stands. This study evaluates tree failure trends across multiple forest types in Northern California by examining how tree-level characteristics influence recent growth and failure occurrence in regionally dominant tree species. Specifically, the …

Early Successional Response To Stream Daylighting In Redwood National And State Parks, Orick, California, Rylee Rawson

Cal Poly Humboldt theses and projects

In-channel stream restoration projects can act as both disturbance and recovery mechanisms, disrupting existing conditions to reestablish the hydrologic and ecological processes that sustain stream ecosystems. These interventions initiate successional trajectories in which channel form and biological communities reorganize over time. In Redwood National and State Parks (California, USA), the Redwoods Rising initiative restores buried headwater channels by recontouring legacy logging roads and daylighting streams buried by Humboldt crossings. Using the National Park Service Klamath Network wadable stream monitoring protocol, I evaluated nine restored reaches spanning one to five years post-restoration, alongside old-growth reference reaches and available pre-treatment data. I …

Forest Management Options For The Wildland Urban Interface: Comparative Analysis Of Stand Development, Economics, And Forest Carbon Over 100 Years In Sierra Nevada Ponderosa Pine, Kassandra A. Mcdaniel

Cal Poly Humboldt theses and projects

This thesis presents a simulation study of various forest stand treatments and their long-term effects on ponderosa pine-dominated forests in the Sierra Nevada Mountain Range of the western USA. The goal was to create recommendations for forest management in the wildland urban interface (WUI) of the Tahoe National Forest and other locations with similar conditions. This study simulates current United States Forest Service (USFS) - Truckee Ranger District silvicultural treatment alternatives repeated over a 100-year period using the USFS Forest Vegetation Simulator (FVS). Proposed treatment alternatives include restoration, resilience, transition, conservation, and no management. Treatments are to be compared in …

Regeneration And Fuel Loading With Varying Overstory Retention In Redwood Stands 10 Years After Transformation To Multiaged Management, Jud Fisher

Cal Poly Humboldt theses and projects

Forest managers using retention forestry in western forests need information on regeneration dynamics and fuel development to design stands that are both productive and fire resilient. This study analyzes 10-year remeasurement data from the Redwood Multiaged Experiment in Jackson Demonstration State Forest, California, comparing regeneration and fuel responses across group selection (GS), aggregated (HA), and dispersed (LD, HD) retention treatments. Target relative density (RD) of the residual stand was zero in GS, 13% in LD, and 21% in HA and HD. Measurements included sprout growth and size of redwood and tanoak, seedling and sprout density, and surface fuel loading.

Redwood …

Ectomycorrhizal Fungi Associated With Pinus Species Of California's Northwestern Coast, Monika Audrey Richardson

Cal Poly Humboldt theses and projects

Ectomycorrhizal (ECM) fungi are vital for increasing host plant uptake of nutrients and stress tolerance within ECM forest ecosystems. The species assemblage of ECM fungi can vary locally in response to numerous biotic and abiotic environmental factors. In California’s northwestern coast the occurrence of three Pinus species, along with a disjunction between populations of Pinus muricata in Mendocino and Humboldt Counties, offer a unique opportunity to investigate the spatial and host effects on pine-associated ECM fungi. Ectomycorrhizal fungal community structure was quantified from host tree roots and sequenced sporocarps occurring at the same sites to create a project specific ITS …

Soil Respiration Drivers And Challenges In A Changing Environment, Olivia Rae Haas

Theses, Dissertations and Culminating Projects

This study aims to understand post agricultural forested soils (sandy loam, silt loam, and loam) and the influences that drive carbon sequestration and soil respiration flux. Duke Farms in Hillsborough NJ, has historically been utilized as an agricultural zone for farming a variety of crops. Currently the area is protected with a focus on environmental conservation and restoration of the land. This includes getting a better understanding of the forested portions of the property. Understanding the quality of forested areas is vital as they have the potential to act as a carbon sink which can mitigate the effects of climate …

Urban Trees In The Urban Hydrology Cycle, Jorge R. Vera

Theses, Dissertations and Capstones

In urban forestry, trees provide numerous economic, ecological, and aesthetic benefits to the surrounding community. One of their key roles is intercepting stormwater runoff, reducing flooding risk, and improving water quality. Chapter 1 of this thesis characterized the ecological and economic contributions of urban trees on the Marshall University campus and provides guidance on their management and conservation in the future. Chapter 2 examined how urban tree species modify the urban hydrology cycle by altering the volume and timing of precipitation delivery. In Chapter 1, we inventoried 114 acres of Marshall University's main campus in Huntington, WV, from June 28 …

A Frog, A Toad, And A Salamander Walk Into A Forest: How Timber Harvest And Environmental Conditions Impact Amphibian Species Abundance In The White Mountain National Forest, William T. Brandenburg

Honors Theses and Capstones

Balancing the needs of humans and wildlife is one of the primary goals of conservation. Understanding how species respond to resource extraction is essential to achieve long-term population stability. This is especially relevant for amphibians, which are particularly sensitive to environmental disturbances due to habitat loss and degradation. As such they are often used as indicator species. This study leverages 20-years of amphibian abundance data from surveys in different silvicultural treatments to understand how American toads (Anaxyrus americanus), wood frogs (Lithobates sylvaticus), and red-backed salamanders (Plethodon cinereus) respond to changes in forest structure, weather, …

Assessing Forest Health And Small Mammals After A Limited Suppression Wildfire In Colville National Forest, Samantha J. Kennel

EWU Masters Thesis Collection

In the face of a wildfire crisis, there is a growing need to expand the pace and scale of forest treatments, including the strategic use of wildfire as a management tool. However, ecological outcomes remain uncertain in forests shaped by more than a century of fire suppression. The 2022 Thor Fire, a managed wildfire in the Colville National Forest, Washington, provides an opportunity to evaluate forest health in a relatively understudied system. Using a control–impact design, I established 100 monitoring plots in burned and adjacent unburned forests to assess how wildfire and fire severity influence forest structure, fuels, and tree …

Climate And Environmental Controls On Forest Soil Organic Matter Cycling, Genevieve Goebel

Dartmouth College Ph.D Dissertations

Climate change factors act on the soil environment in complex ways, known to disturb soil organic carbon (C). Rising global temperatures and alterations to regional precipitation and nitrogen deposition regimes may contribute to the intensification of global change by accelerating the rate of biological decomposition and CO2 efflux to the atmosphere. The magnitude and endurance of the disturbance to soil organic C across landscapes and throughout time that climate change factors may pose to soil C cycling are not comprehensively understood. These knowledge gaps in our field make it challenging to anticipate how soil environments and the vast ecosystems that …

Following The Water: Tree Water Sources In Coastal Northern California Forests, Kaitlyn Briggs

Cal Poly Humboldt theses and projects

Increasing drought intensity and declining summer water availability in Mediterranean- climate forests raise concerns about forest resilience and streamflow persistence. This study evaluated how tree water sources vary with hillslope position, season, species, and watershed context across three coastal northern California forests. Stable isotopes of hydrogen (δD) and oxygen (δ18O), soil moisture time series, linear mixed-effects models, and site-specific Bayesian mixing models (MixSIAR) were used to estimate proportional contributions of shallow soil, deep soil, stream-associated, and fog water to tree xylem water. Across sites, xylem water isotopic signatures overlapped primarily with soil water, indicating dominant reliance on subsurface sources, while …

Relational Approaches To Fire Resilience: Designing A Living Shaded Fuel Break With Indigenous Knowledge Systems, Natalee Nicole Lopes

Cal Poly Humboldt theses and projects

Escalating wildfire severity across California reflects not only changing climatic conditions but also the cumulative impacts of colonial land management systems that have disrupted Indigenous fire stewardship and altered forest structure and function. This project examines how wildfire mitigation infrastructure, specifically linear fuel treatments, such as fuel breaks, can be reimagined through Indigenous relational frameworks of care-based land stewardship. Grounded in Happy Camp (Athithúfvuunupma), California, within the ancestral homelands of the Karuk Tribe along the mid-Klamath River, this research is carried out in collaboration with Karuk knowledge holders, centering Indigenous knowledge systems and priorities.

Using a mixed-methods approach that integrates …

Effects Of Conifer Encroachment On Oregon White Oak Crown Structure And Nonvascular Epiphyte Communities, Courtney Jonell Copper

Cal Poly Humboldt theses and projects

Oregon white oak (Quercus garryana, QUGA) is an ecologically and culturally important broadleaf tree species native to northern California and the Pacific Northwest. Fire suppression and subsequent encroachment by Douglas-fir (Pseudotsuga menziesii, PSME) and other conifers have made QUGA woodlands among the most threatened habitat types in the region. This study examines the influence of conifer encroachment on QUGA crown structure and nonvascular epiphyte (NVE) communities using ground- and crown-based sampling techniques.

Twenty-four trees were sampled across four sites in northern California along a gradient of conifer encroachment that was quantified as PSME basal area (BA). A …

Long-Term Relationships Between Tree Growth And Climate In The Trinity Alps Wilderness, Klamath Mountains, California, Usa, Emma R. Knepp

Cal Poly Humboldt theses and projects

The Trinity Alps Wilderness is a unique setting for evaluating late-Holocene climate variability because former glaciers occupied comparatively low elevations in a region influenced by both coastal and interior climate patterns. Tree-ring chronologies were developed from four conifer species—Shasta red fir (Abies magnifica var. shastensis), western white pine (Pinus monticola), Brewer’s spruce (Picea breweriana), and mountain hemlock (Tsuga mertensiana)—sampled at high elevations (1950 - 2300 m) near Emerald and Grizzly Lakes in the Trinity Alps Wilderness in northern California. The final chronologies included 12 Shasta red fir trees, 12 western white pine …

Baker Cypress (Hesperocyparis Bakeri) In A Changing Fire Landscape: Characterizing Fire Refugia And Guiding Post-Fire Reforestation, Olivia Lorraine Moskowitz

Cal Poly Humboldt theses and projects

Increasing wildfire frequency threatens serotinous, fire-obligate species that depend on sufficient fire-free intervals to develop seed banks for reproduction. These species require fire intense enough to trigger seed release and create favorable substrate and light levels for regeneration, yet consecutive fires that reburn populations before they reach maturity can cause local population contraction or extirpation. Understanding the environmental drivers of natural regeneration and mature tree survival, as well as when and how active reforestation should supplement natural recovery, is critical for managing fire-adapted species under altered fire regimes.

This thesis uses Baker cypress (Hesperocyparis bakeri [Jeps.] Bartel), a rare …