Forest Sciences Commons^™

Investigating Dimensions Of Social Vulnerability To Wildfire: A Case Study Of Western Montana, Ella Brodowski

Dissertations, Master's Theses and Master's Reports

Communities across the US are facing increased wildfire risks due in part to historic fire suppression efforts, a warming climate, and an influx of people residing in wildland urban interface (WUI) landscapes. Because of these increasing risks, there have been growing concerns about the social factors that can increase individual and community vulnerability to wildfires. This research adds to the discussion of social vulnerability by examining how people living in a geographic area with heightened wildfire risk think about the ways in which people can be more or less vulnerable to wildfires. Using semi-structured interviews, round table discussions, and field …

Relict Ponderosa Pine Mortality And Fuels Study In The Bob Marshall Wilderness, Montana, Usa, Laura K. Schimmel

Dissertations, Master's Theses and Master's Reports

Many forests have historically experienced mixed-severity fire regimes that were disrupted during the 20th century due to fire exclusion policy. A stand of relict Pinus ponderosa in the Bob Marshall Wilderness Complex that burned in 2003, 2011, and 2018 provides a unique case study for investigating the effects of returned fire to the landscape. Many of the trees have fire scars or Indigenous bark-peeling scars, preserving valuable ecological and anthropological history. We sought to determine whether scarred trees were more susceptible to fire damage, if larger trees had greater fire resilience than smaller trees, and if fuel loads have changed …

Sugar Maple (Acer Saccharum Marsh.) Tree-Ring Growth And Carbon Stable Isotope Responses To Nitrogen And Climate, Libbie Ring

Dissertations, Master's Theses and Master's Reports

This dendrochronological and stable carbon isotope study used tree rings from sugar maple (Acer Saccharum Marsh.) collected at long-term nitrogen (N) amended sites throughout Michigan to understand N amendment and deposition, climate, and growth relationships. Climate responses varied by site, however, we found importance in grouping sites by “productivity” which is related to inherent N and soil nutrients. Our results did not detect an overall effect of N amendments on growth during the treatment period. However, data shows N amendments benefiting larger diameter trees, while smaller diameter trees responded more positively without amendments, especially on more productive sites. Results …

Small Mammal Diet As An Indicator Of Lyme Disease And The Road To Endemicity In Michigan’S Upper Peninsula, Jacqueline E. Suits

Dissertations, Master's Theses and Master's Reports

Lyme disease is expanding in the Upper Midwest due to climate change, forest degradation, and shifting wildlife communities. Small mammals are key reservoir hosts, and their foraging behavior offers insight into environmental conditions that sustain pathogen transmission. We used DNA metabarcoding to investigate small mammal diets across seasonal, spatial, and infection gradients in Michigan’s Upper Peninsula. We identified dominant dietary plant and arthropod taxa, seasonal shifts, and slight variation by species, site, and Lyme infection status. Taxa associated with Lyme-positive individuals were primarily linked to moist, edge, and disturbed habitats, areas that also support ticks and disease spread. These results …

Growth, Survival, And Herbivore Browsing Preferences Of Seedlings Planted In Black Ash Stands Of Northern Michigan And Wisconsin, Seth W. Davenport

Dissertations, Master's Theses and Master's Reports

To mitigate the cascading ecosystem impacts of widespread black ash (Fraxinus nigra) mortality due to the invasive emerald ash borer (Agrilus planipennis), forested wetlands can be underplanted with seedlings of alternative species that later repopulate the vacated canopy. This study examined the survival and growth, factors influencing performance, and herbivore browsing preferences of seven non-ash species planted in northern Michigan and Wisconsin. The best performing species were river birch (Betula nigra), silver maple (Acer saccharinum), and swamp white oak (Quercus bicolor). The worst performing species was black spruce (Picea …

Rotten Through The Cores: What Decomposition Can Tell Us About Carbon Cycling, Eileen C. Reeves

Dissertations, Master's Theses and Master's Reports

Sequestration of carbon (C) in forests means that the C is stored in the ecosystem and not emitted to the atmosphere, thus slowing the accumulation of greenhouse gases and mitigating the acceleration of manmade climate change. Quantifying the pools and fluxes of C in forests is therefore of considerable interest to landowners, policy makers, and scientists.

Decomposition is an ecological process central to the movement of C through ecosystems. This dissertation uses several techniques to help determine the factors influencing the speed of decomposition and long-term fate of decomposed plant material. In Chapter Two, phospholipid fatty acid analysis was used …

Dam It All: A Multi-Scalar Investigation Into The Ecological Role And Function Of Beaver Dams, Kenneth Larsen

Dissertations, Master's Theses and Master's Reports

The central theme of this dissertation is ecological scaling, which examines how small, localized features, such as beaver ponds, contribute to large-scale watershed processes and how different modeling approaches at various scales reveal distinct insights. Through a combination of probabilistic modeling and high-resolution empirical research, this work demonstrates that small ponded systems, particularly those created by beavers (Castor canadensis), serve as critical biogeochemical control points, whose contributions to sediment and nutrient dynamics have been historically underestimated.

In Chapter 1, I contextualize this research within the broader fields of freshwater ecology, watershed modeling, and ecological restoration. I introduce the …

Risk Of Oak Wilt Expanding Northward: Examining Nitidulidae Vector Communities And Host Phenology Beyond The Current Disease Range, Kathleen E. Bershing

Dissertations, Master's Theses and Master's Reports

Oak wilt is a fatal fungal pathogen to oak trees, caused by the fungus Bretziella fagacearum. This fungus targets oak species (Quercus spp.), where members of the red oak group (sect. Lobatae) are at greatest risk of mortality. Oak wilt is widespread throughout the eastern United States, currently present in 24 states. Recently in 2023, oak wilt was detected in trees for the first time in Canada. Although removed from the locations of the first Canadian detections, there is continual concern that the range of oak wilt is at risk for expansion northward. This is further evident …

The Effects Of Strip Clearcutting On Natural And Artificial Northern Red Oak Regeneration In A Central Appalachian Hardwood Stand, Patrick Aaron Plaugher

Graduate Theses, Dissertations, and Problem Reports (ETD)

There are well-known difficulties associated with regenerating oak stands throughout the Central Hardwoods region. To successfully regenerate oak, competitive sources of advance reproduction are required ahead of harvesting—a condition that is rarely present, especially on productive sites. While treatments that enhance seedling competitiveness (e.g., midstory removals, burning, vegetation control) are available, in practice, these are rarely implemented and/or effective because of large treatment costs and/or because they require delaying harvest.

As a potential alternative practice, we report the 10-yr results of a strip clearcut regeneration method. This method removes alternating 45-m wide strips across a mixed Appalachian hardwood …

Linking Empirical Data And Numerical Simulation To Characterize Dynamic Fire Behavior Associated With Interacting Firelines, Marta Sergeevna Jerebets

Graduate Student Theses, Dissertations, & Professional Papers

Understanding fuel pattern-fire process relationships is key for predicting fire behavior and effects with follow-on benefits to proactive fire management and model validation. To characterize dynamic fire behavior, this thesis leverages empirical data and numerical simulation through two complementary studies.

In the first study, longwave thermal sensors aboard unmanned aerial systems (UAS) were used to capture fine-scale fire behavior in two experimental grass burns. A novel paired design was used to quantify the effects of fuel arrangement on fire behavior with 3.66 m diameter treatments cut to a height of 0.15 m. The treatments ephemerally reduced fire rate of spread …

Modeling Neighborhoods As Fuel For Wildfire, Bryce Alan Young

Graduate Student Theses, Dissertations, & Professional Papers

Wildfire models drive billions of dollars in risk mitigation efforts. However, the modeling community currently lacks a representative fuelscape on which to base simulations of fire spread in the built environment and the wildland-urban interface (WUI) where vegetation and structures act together as fuel for wildfire. This thesis advances wildfire risk modeling by addressing the underdeveloped representation of the built environment in existing frameworks. By identifying inconsistencies in how structure and defensible space features are defined and used across empirical studies, predictive indices, and fire spread models, this research lays the groundwork for standardized modeling approaches and feature selection (Chapter …

Bridging The Gap Between Plot-Level And Landscape-Scale Analysis For Wildfire Risk Assessment, Vanessa Leigh Niemczyk

Graduate Student Theses, Dissertations, & Professional Papers

Remote sensing technology has advanced greatly over the past couple of decades proving its ability to aid in wildfire risk assessment and improve our understanding of forest structure and fuel inventory across the landscape. While some aerial and satellite sensors perform better than others, they all have a common weakness, their reduced ability to capture understory fuels with high detail. Terrestrial laser scanning is an emerging solution due to its understory perspective. This research leverages the beneficial aspects of both terrestrial laser scanning and various aerial- or satellite-based remote sensing platforms (aerial laser scanning, digital aerial photogrammetry, and Sentinel-2) to …

Ineligible Partners: Tribal Nations And Cooperative Federalism In The Historical Development Of National Forest Law And Policy, James H. Baker

Graduate Student Theses, Dissertations, & Professional Papers

Lands within the National Forest System (NFS), like all federal public lands, are rooted in Aboriginal Title and were once exclusively inhabited by Indigenous peoples and communities. Through the process of treaty-making, the federal government amassed millions of acres of ceded Tribal lands, many of which are now managed by federal public land agencies, including 194 million acres managed by the U.S. Forest Service (USFS). Several Tribes reserved various use and property rights on these lands that are protected by the U.S. Constitution’s Treaty and Supremacy Clauses. The federal government also has an overarching trust obligation to Tribes – a …

A Retrospective Assessment Of Post-Fire Planting In The Us: Aligning Actual And Optimal Planting Sites To Address The Reforestation Gap, Lewis Faller

Graduate Student Theses, Dissertations, & Professional Papers

The natural regeneration processes that maintain semi-arid North American conifer forests are being disrupted. Increasingly, large wildfires burn core areas beyond the typical seed dispersal range of surviving adult trees and even when seeds are present, climate conditions increasingly are unsuitable for conifer recruitment, establishment, and survival. The USDA Forest Service (USFS), mandated to maintain forest cover in response to harvest or disturbance, now faces a planting backlog of over 3.8 million acres. Here, we conduct a retrospective assessment (1986–2023) of USFS post-fire reforestation to evaluate (1) whether historical planting patterns align with the goal to close the national reforestation …

The Role Of Floodplain Complexity In Wood Turtle Habitat Use, Laura S. Deming

Antioch University Dissertations & Theses

Wood turtles occupy cold, low-gradient riverine habitat throughout the northeastern United State and southeastern Canada. Stream alterations, such as dams, channel straightening, and floodplain development have diminished the natural hydrologic and sedimentation regimes that result in complex channel and floodplain geomorphology. Studies throughout the species’ range have quantified many aspects of their habitat, but none have quantified components of geomorphology of wood turtle sites. The goal of this study was to explore the role of stream channel and floodplain geomorphology in wood turtle habitat use, with specific objectives to (1) quantify components of stream channel and floodplain geomorphic complexity, (2) …