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Articles 1 - 30 of 134

Full-Text Articles in Forest Sciences

Exploring The Composition Of Forest Collaboratives In Northeastern Oregon, Lee K. Cervany, Rebecca J. Mclain, Kristen Wright Jul 2025

Exploring The Composition Of Forest Collaboratives In Northeastern Oregon, Lee K. Cervany, Rebecca J. Mclain, Kristen Wright

National Policy Consensus Center Publications and Reports

Community-based collaboration has been touted as an effective model for forest governance because it promotes democratized decision-making and stakeholder engagement to address landscape-scale problems. Forest collaboratives are assumed to be heterogeneous, consisting of stakeholders with a diverse range of interests. Few studies have systematically explored variables associated with collaborative composition. We identify six elements of collaborative composition for investigation: size, stakeholder diversity, balance, locality–diversity, core attendance, and cross-participation. This exploratory study examines five forest collaborative groups in eastern Oregon (USA). We analyzed meeting minutes over an 18-month period to track attendance and evaluate who shows up and at what frequency. …


Indigenous Science And The Legacy Of Fire: Resilience, Fuels, Mosaics, And Eco-Cultural Landscapes In Oregon’S Coastal And Cascade Range, Julia Alcalá Jun 2025

Indigenous Science And The Legacy Of Fire: Resilience, Fuels, Mosaics, And Eco-Cultural Landscapes In Oregon’S Coastal And Cascade Range, Julia Alcalá

University Honors Theses

Most of Oregon's western Cascade and Coastal range is a landscape that has historically been considered devoid of mid to low-intensity fires by Western science. However, for time immemorial, Indigenous peoples have been stewarding the forests through the use of "good fire," creating diverse and heterogenous landscapes with mixed fire regimes, ranging from less than a decade to several centuries since the last fire, resulting in a mosaic of patchy forest, oak savannas, prairies, and wetlands. Yet centuries of Indigenous displacement, cultural assimilation, and suppression of cultural burning contributed to this prevailing belief. Despite that, in recent decades, Western scientists …


Estimated Amounts Of Terrestrial Carbon Mobilized And Sequestered By The 1980 Mount St. Helens Eruption, Washington State, Usa, Lizzet G. Reyes Apr 2025

Estimated Amounts Of Terrestrial Carbon Mobilized And Sequestered By The 1980 Mount St. Helens Eruption, Washington State, Usa, Lizzet G. Reyes

Dissertations and Theses

Volcanic eruptions significantly influence the geologic carbon cycle by emitting CO2 and mobilizing terrestrial carbon pools. The 1980 Mount St. Helens (MSH) eruption offers a unique case study, triggering a massive landslide that displaced 2.7 km3 of sediment, buried 600 km2 of forest, and disrupted regional carbon dynamics. Pre-eruption terrestrial carbon stocks, including aboveground biomass (AGB), dead biomass (D), and soil organic carbon (S), averaged 209.5 tC/ha. Post-eruption, total carbon density fell to 118.7 tC/ha, driven mainly by a 51% reduction in AGB, modest declines in D, and redistribution of S. Over 36 years, ecosystem recovery increased …


Color Aberrations In Seven Bird Species In Costa Rica, Lucia Isabel Lopez, Jose Manuel Mora, Adrian Alvarado Rivera Mar 2025

Color Aberrations In Seven Bird Species In Costa Rica, Lucia Isabel Lopez, Jose Manuel Mora, Adrian Alvarado Rivera

Biology Faculty Publications and Presentations

Although there are 935 species of birds in Costa Rica, scientific reports of pigmentation abnormalities in this group are limited. Nevertheless, several cases have been recently documented, including Leucism, Ino mutation, Progressive Graying, Dilution, and two unusual color aberrations in a toucan and a motmot. Here we describe seven cases of color aberrations observed over a period of five years in native birds of Costa Rica. An Eastern Wood-Pewee Contopus virens and a White-collared Manakin manacus candei were Brown. A Scintillant Hummingbird Selasphorus scintilla and a Talamanca Hummingbird, Eugenes spectabilis, also showed a Brown mutation, however, these two cases may …


Monitoring And Modeling Legacy Tree Response To Restoration Treatments In The Klamath Mountains, Oregon, Usa, Isaac Joseph Ball Feb 2025

Monitoring And Modeling Legacy Tree Response To Restoration Treatments In The Klamath Mountains, Oregon, Usa, Isaac Joseph Ball

Dissertations and Theses

Climate change and its disruption of historical drought and wildfire patterns pose a substantial threat to forest health in the western United States. This threat is compounded by past management practices like fire suppression. The largest, oldest, and most ecologically valuable trees are particularly vulnerable, making their conservation a key objective of climate-adaptive forest management. Restoration treatments such as mechanical thinning have been shown to enhance tree growth and drought resilience in dry conifer forests, but long-term monitoring is necessary to understand their sustained effects. This study used dendroecological tree-ring analysis to investigate the effects of thinning on the growth, …


Collaborative Wildfire Governance Within The Southwest Idaho Wildfire Crisis Strategy Landscape: Survey Results 2025, Mahmood Muttaqee, Cody R. Evers, Lindsay K. Campbell, Max Nielsen-Pincus, Olivia Awbrey, Kathryn Hixson, Michelle Johnson, Erika Svendsen Jan 2025

Collaborative Wildfire Governance Within The Southwest Idaho Wildfire Crisis Strategy Landscape: Survey Results 2025, Mahmood Muttaqee, Cody R. Evers, Lindsay K. Campbell, Max Nielsen-Pincus, Olivia Awbrey, Kathryn Hixson, Michelle Johnson, Erika Svendsen

Environmental Science and Management Faculty Publications and Presentations

Collaboration plays a critical role in wildfire risk mitigation efforts. This study examines collaborative wildfire governance networks within Southwest Idaho, a priority landscape designated in 2022 under the USDA Forest Service's Wildfire Crisis Strategy (WCS). Through survey data from 64 respondents, the Fueling Adaptation study aimed to identify the structure, capacity, and gaps in governance networks addressing wildfire risk in Southwest Idaho and understand how WCS investments have influenced wildfire management in the area. The findings reveal a growing governance network centered on the USDA Forest Service and the Idaho Department of Lands and supported by numerous non-governmental organizations and …


Uncovering The Dynamic Nature Of Fire Refugia Across Landscapes In Oregon's Western Cascades, Alec Scott Dyer Jun 2024

Uncovering The Dynamic Nature Of Fire Refugia Across Landscapes In Oregon's Western Cascades, Alec Scott Dyer

Dissertations and Theses

With increased fire activity, the presence of fire refugia is critical to support forest resiliency and mitigate large-scale vegetation conversion, however, the persistence of fire refugia within burn perimeters over time is uncertain. This study examines the dynamic nature of fire refugia by mapping the decline in forest cover over time, identifying spatiotemporal patch- and landscape-scale patterns and the biophysical drivers of delayed mortality following the 2020 Labor Day Fires occurring in Oregon’s western Cascades. After three years post-fire, delayed mortality accounted for an additional 8.5% of forest loss (total of 24,147 hectares in all five burns) compared to pre-fire …


Non-Native Rhizophora Mangle As Sinks For Coastal Contamination On Moloka’I, Hawai’I, Geoffrey Szafranski, Elise F. Granek, Michelle L. Hladik, Mia Hackett Apr 2024

Non-Native Rhizophora Mangle As Sinks For Coastal Contamination On Moloka’I, Hawai’I, Geoffrey Szafranski, Elise F. Granek, Michelle L. Hladik, Mia Hackett

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests provide a suite of environmental services, including sequestration of anthropogenic contamination. Yet, research lags on the environmental fate and potential human health risks of mangrove-sequestered contaminants in the context of mangrove removal for development and range shifts due to climate change. To address this, we conducted a study on Moloka'i, Hawai'i, comparing microplastic and pesticide contamination in coastal compartments both at areas modified by non-native red mangroves (Rhizophora mangle) and unmodified, open coastline. Sediment, porewater, and mangrove plant tissues were collected to quantify microplastic and pesticide concentrations across ecosystem type. Average microplastics were similar between …


Postfire Effects And Regeneration Patterns In Araucaria-Nothofagus Forests In South-Central Chile, Paola A. Arroyo-Vargas Dec 2023

Postfire Effects And Regeneration Patterns In Araucaria-Nothofagus Forests In South-Central Chile, Paola A. Arroyo-Vargas

Dissertations and Theses

Fire regime shifts due to climate and land use changes are threatening ecosystems worldwide, affecting their capacity to recover after severe wildfires. Increase of fire frequency, severity and intensity may severely affect forest ecosystems whose fire regimes have been characterized by infrequent stand-replacing fires. The temperate forests of southern South America, specifically the Andean temperate forests dominated by the conifer Araucaria araucana and the angiosperm species from Nothofagus genus, have evolved with less fire pressure, where severe wildfires may happen after decades or centuries. Recent severe and short-interval fires exacerbated by warmer and drier climate conditions have affected these forests, …


Exploring And Testing Wildfire Risk Decision-Making In The Face Of Deep Uncertainty, Bart R. Johnson, Alan A. Ager, Cody Evers, David Hulse, Max Nielsen-Pincus, John P. Bolte Aug 2023

Exploring And Testing Wildfire Risk Decision-Making In The Face Of Deep Uncertainty, Bart R. Johnson, Alan A. Ager, Cody Evers, David Hulse, Max Nielsen-Pincus, John P. Bolte

Environmental Science and Management Faculty Publications and Presentations

We integrated a mechanistic wildfire simulation system with an agent-based landscape change model to investigate the feedbacks among climate change, population growth, development, landowner decision-making, vegetative succession, and wildfire. Our goal was to develop an adaptable simulation platform for anticipating risk-mitigation tradeoffs in a fire-prone wildland– urban interface (WUI) facing conditions outside the bounds of experience. We describe how five social and ecological system (SES) submodels interact over time and space to generate highly variable alternative futures even within the same scenario as stochastic elements in simulated wildfire, succession, and landowner decisions create large sets of unique, path-dependent futures for …


Disentangling Groundwater Dynamics At Oregon's Mckenzie River Headwaters, Taylor Nicole Salazar Jul 2023

Disentangling Groundwater Dynamics At Oregon's Mckenzie River Headwaters, Taylor Nicole Salazar

Dissertations and Theses

Widespread mountain snowpack declines have been occurring across the western United States over the last century, and are increasing in duration and severity, with several record-breaking low-snowpack years in the last decade. In the Pacific Northwest, summer streamflow is largely a result of melting snow and groundwater discharge, as summers are typically dry and warm in this Mediterranean bioclimate, thus making spring-fed rivers critical for regional water resources. However, current trends and predictions in hydroclimate modeling indicate spring-fed rivers will experience reduced summer discharge driven by the increasingly larger impact of anthropogenic climate change (warming) on (decreased) mountain snowpack. A …


Willow Abundance And Condition Mapping In Rocky Mountain National Park, Eric M. Nielsen May 2023

Willow Abundance And Condition Mapping In Rocky Mountain National Park, Eric M. Nielsen

Institute for Natural Resources Publications

Riparian and wetland willow species have undergone serious declines in Rocky Mountain National Park as a consequence of a variety of environmental changes and, most recently, damage resulting from moose overpopulation. To address concerns about the long-term status of willows in the park, we developed remote sensing-based raster maps of riparian and wetland willow species presence, canopy cover percentage, canopy height, and leaf area index. All outputs were produced at 3-meter resolution, and represent willows as they existed in 2021. The mapping was performed via random forests classification and regression models trained on several hundred vegetation plots from a variety …


An Examination Of The Current Knowledge Of Contaminants In Mangroves: Hawaii And Globally, Geoffrey Szafranski Apr 2023

An Examination Of The Current Knowledge Of Contaminants In Mangroves: Hawaii And Globally, Geoffrey Szafranski

Environmental Science and Management Professional Master's Project Reports

The geographic range of mangrove forests is shifting quickly as they expand poleward in response to climate change while simultaneously being removed from their native extent to clear space for anthropogenic land-uses. Mangrove forests are also known to be sinks for anthropogenic contamination. Yet contamination research is under-researched in mangrove ecosystems, specifically the environmental fate, effect on biodiversity, and risk to human populations from contamination in the context of these changing conditions requires further research. The goal of this thesis is to address this data gap through analysis of contamination in the literature and through an investigational survey of mangrove …


Post-Fire Erosional And Hydrological Processes Promoting Debris Flow Initiation In A Douglas Fir And Western Hemlock Forest In The Riverside Burn Area, Oregon, Morena Nicole Hammer Aug 2022

Post-Fire Erosional And Hydrological Processes Promoting Debris Flow Initiation In A Douglas Fir And Western Hemlock Forest In The Riverside Burn Area, Oregon, Morena Nicole Hammer

Dissertations and Theses

Post-fire debris flows initiated by overland flow in the Pacific Northwest (PNW) are largely undocumented. Instead, debris flows are typically initiated by shallow landslides that result in a mud slurry of water and sediments traveling downhill under the force of gravity. However, because of the Fall 2020 fires in Oregon, the typical initiation style and erosional patterns in burned catchments may have changed because of unusually high burn severity. Due to the intensity of these fires, we set out to determine how hydrologic processes and erosion occurred, when they occurred, and what process was primarily responsible for the erosion that …


Post-Fire Tree Mortality And Regeneration Patterns As Proxies Of Conifer Forest Resilience, Sebastian Upton Busby Dec 2021

Post-Fire Tree Mortality And Regeneration Patterns As Proxies Of Conifer Forest Resilience, Sebastian Upton Busby

Dissertations and Theses

Shifting wildfire patterns and climate conditions, magnified by anthropogenic climate change, are threatening the resilience of conifer forests in North America and more specifically, the western US. If native conifer species are functionally maladapted to novel fire patterns and post-fire climate conditions, large-scale shifts in conifer forest structure, composition, and extent may occur as warming intensifies. Forest resilience in the context of fire and climate can be understood and quantified by the survival of trees through fire events and success of trees to regenerate post-fire and maintain population levels. In this dissertation, I use field observations and remote sensing to …


Modeling Environmental Factors Related To Drought-Induced Tree Mortality Based On Lidar And Hyperspectral Imagery, Lauren Nicole Sharwood Nov 2021

Modeling Environmental Factors Related To Drought-Induced Tree Mortality Based On Lidar And Hyperspectral Imagery, Lauren Nicole Sharwood

Dissertations and Theses

Climate change is projected to bring more frequent and prolonged droughts, causing widespread forest die-off. Identifying tree mortality over large spatial extents in response to the most recent California drought will help forest managers and conservationists understand where there may be a greater likelihood of future die-offs. In order to find more at-risk areas, this study evaluated how interacting site-specific topographic, climate, substrate, and stand characteristics mediated tree mortality in the Central Sierra Nevada during the 2012-2016 drought. The author used lidar and hyperspectral imagery provided by the National Ecological Observatory Network to identify individual dead trees using the Random …


Planning For Future Fire: Scenario Analysis Of An Accelerated Fuel Reduction Plan For The Western United States, Alan A. Ager, Cody Evers, Michelle A. Day, Fermin J. Alcasena, Rachel Houtman Nov 2021

Planning For Future Fire: Scenario Analysis Of An Accelerated Fuel Reduction Plan For The Western United States, Alan A. Ager, Cody Evers, Michelle A. Day, Fermin J. Alcasena, Rachel Houtman

Environmental Science and Management Faculty Publications and Presentations

Recent fire seasons brought a new fire reality to the western US, and motivated federal agencies to explore scenarios for augmenting current fuel management and forest restoration in areas where fires might threaten critical resources and developed areas. To support this effort, we modeled the scheduling of an accelerated forest and fuel management scenario on 76 western US national forests. Specifically, we modeled a 10-year ramp up of current forest and fuel management that targeted the source of wildfire exposure to developed areas and simulated treatment in areas that accounted for 77% of the predicted exposure. We used a sample …


Multi-Scale Environmental Conditions Associated With Shade-Tolerant Conifer Regeneration In Forest Park, Portland, Oregon, Matthew Cook Aug 2021

Multi-Scale Environmental Conditions Associated With Shade-Tolerant Conifer Regeneration In Forest Park, Portland, Oregon, Matthew Cook

Dissertations and Theses

Forest Park is a 5,100-acre urban forest located in Portland, Oregon, that has been impacted by various anthropogenic stressors including logging, fragmentation, invasive species, air pollution and recreation use due to its proximity to the urban environment. This legacy of land use coupled with natural disturbances has resulted in changes to forest structure, composition, and function--threatening the long-term sustainability of the park. Past research in Forest Park has identified a lack of regenerating shade-tolerant conifers, particularly western hemlock and western red cedar species, in the section of the park closest to the city. Typically, western hemlock and western red cedar …


Opportunities And Challenges In The Collection And Use Of Socio-Spatial Data In National Forest Planning, Diane Trechsel Besser Aug 2021

Opportunities And Challenges In The Collection And Use Of Socio-Spatial Data In National Forest Planning, Diane Trechsel Besser

Dissertations and Theses

Understanding human-environment connections to places is an important component of land-use management. Tools for collecting geographically referenced public values-based data (defined as socio-spatial data) for use in natural resource planning have been reported in academic journals for decades. The utility of socio-spatial data is in making public values tangible and potentially actionable in land-use analyses and decision processes. However, there is a lack of comprehensive documentation on the ways in which socio-spatial data is perceived, collected, interpreted and applied at a practical level. A better understanding of these factors allows planners to mitigate barriers and leverage opportunities to more …


Beaver Reintroduction And Its Potential As An Ecological Conservation Measure For At-Risk Amphibian Species In The Pacific Northwest, Danielle Schwantes Jul 2021

Beaver Reintroduction And Its Potential As An Ecological Conservation Measure For At-Risk Amphibian Species In The Pacific Northwest, Danielle Schwantes

University Honors Theses

Amphibian decline is a major concern in the Pacific Northwest (PNW), with many amphibian species listed as sensitive, threatened or endangered throughout the region. Some of the predicted main causes of amphibian decline are climate change and loss of habitat. The reintroduction of beavers into ecoregions of the PNW could be an important step in the conservation of this region’s amphibians, due to the beaver’s ability to engineer and structurally manipulate forest ecosystems. Beavers are able to restore wetland quality, productivity and biodiversity, creating vital amphibian habitat. This work explored the linkage between beaver presence and wetland hydrology, geomorphology, landscape …


Understory Species Increase Project: Investigating The Revegetation Of Native Herbaceous Species From Seed In Urban Forest Fragments, Erin Mcelroy Jun 2021

Understory Species Increase Project: Investigating The Revegetation Of Native Herbaceous Species From Seed In Urban Forest Fragments, Erin Mcelroy

Environmental Science and Management Professional Master's Project Reports

Management of urban forest fragments often aims to reduce invasive species and promote native species abundance and diversity. Often, these environments lack natural establishment of native forest species, including herbaceous species that are especially sensitive to site conditions. While herbaceous understory species may represent a small proportion of forest biomass, they perform important functions within forest environments, including nutrient cycling, erosion and runoff control, and providing habitat for wildlife, as well as hosting the greatest biodiversity among other forest strata. However, many restoration projects focus primarily on the revegetation of dominant woody forest species, such as hardwood trees and shrubs. …


Influence Of Climate Change On Forest Fire Occurrence And Distribution Of Sri Lanka And Modeling Of Forest Fire, Mohan Heenatigala Jun 2021

Influence Of Climate Change On Forest Fire Occurrence And Distribution Of Sri Lanka And Modeling Of Forest Fire, Mohan Heenatigala

Environmental Science and Management Professional Master's Project Reports

Forest fire is one of the main causes for forest degradation and deforestation which affect ecosystem services provided by the given landscapes. Weather variables like temperature, wind speed and direction, rainfall, and relative humidity also govern the forest fire regime and vulnerability. On the other hand, forest fuel characteristics, human impacts, population density, forest canopy density, slope, elevation, road density, closeness to the human settlement areas are other factors that determine the forest fire impact and potential of damage. Annually, 100 to 2500 hectares of forest resources are damaged due to forest fires in Sri Lanka. From the past few …


Projected Impact Of Mid-21st Century Climate Change On Wildfire Hazard In A Major Urban Watershed Outside Portland, Oregon Usa, Andy Mcevoy, Max Nielsen-Pincus, Andres Holz, Arielle J. Catalano, Kelly E. Gleason Dec 2020

Projected Impact Of Mid-21st Century Climate Change On Wildfire Hazard In A Major Urban Watershed Outside Portland, Oregon Usa, Andy Mcevoy, Max Nielsen-Pincus, Andres Holz, Arielle J. Catalano, Kelly E. Gleason

Environmental Science and Management Faculty Publications and Presentations

Characterizing wildfire regimes where wildfires are uncommon is challenged by a lack of empirical information. Moreover, climate change is projected to lead to increasingly frequent wildfires and additional annual area burned in forests historically characterized by long fire return intervals. Western Oregon and Washington, USA (westside) have experienced few large wildfires (fires greater than 100 hectares) the past century and are characterized to infrequent large fires with return intervals greater than 500 years. We evaluated impacts of climate change on wildfire hazard in a major urban watershed outside Portland, OR, USA. We simulated wildfire occurrence and fire regime characteristics under …


Variability In Historical Fire Patterns Of A Moist Mixed-Conifer Forest In The Northern Blue Mountains Of Oregon, Laura Marie Platt Jul 2020

Variability In Historical Fire Patterns Of A Moist Mixed-Conifer Forest In The Northern Blue Mountains Of Oregon, Laura Marie Platt

Dissertations and Theses

High variability in historical fire patterns characteristic to mixed-severity fire regimes is expected to have contributed to a structurally heterogeneous landscape throughout much of the forested ecosystems of the western United States. After more than a hundred years of fire exclusion in the region, many forests have shifted to a more homogeneous structure, which raises concern regarding these forests' ability to sustain expected increases in fire activity with a warming climate. The shift is not uniform across the west, however, and differences in historical disturbance patterns and changes due to land management are not well characterized in forests across a …


A Framework For Incorporating Benefits From Urban Forests Into Planning For Livable Cities: A Case Study Of Forest Park, Carole Hardy Jul 2020

A Framework For Incorporating Benefits From Urban Forests Into Planning For Livable Cities: A Case Study Of Forest Park, Carole Hardy

Environmental Science and Management Professional Master's Project Reports

Urban forests provide an escape from the noise and chaos of cities. Other services can be overlooked and under-valued. Urban forests cool and filter the air, sequester carbon, filter water removing toxins and sediments from urban runoff, provide habitat for wildlife and improve human health and well-being. Commonly urban forests in the United States (US) lack funds for restoration and research because there is lack of understanding of the need to actively manage what are perceived as wild lands. Generally urban forests are highly disturbed and novel ecosystems that require ongoing active management to remove invasive species, replant native species …


Vulnerability Of Small Forest Patches To Fire In The Paraiba Do Sul River Valley, Southeast Brazil: Implications For Restoration Of The Atlantic Forest Biome, Betina J. Guedes, Klecia G. Massi, Cody Evers, Max Nielsen-Pincus Jun 2020

Vulnerability Of Small Forest Patches To Fire In The Paraiba Do Sul River Valley, Southeast Brazil: Implications For Restoration Of The Atlantic Forest Biome, Betina J. Guedes, Klecia G. Massi, Cody Evers, Max Nielsen-Pincus

Environmental Science and Management Faculty Publications and Presentations

The Atlantic Forest biome, a biodiversity hotspot historically threatened by deforestation and human disturbance, has recently seen a net gain in native forest cover due to changes in land use, enactment of new laws, and substantial investment in restoration. Like many South American and global ecosystems, the Atlantic Forest biome has also experienced an increase in area burned by wildfire largely due to human ignitions, which threatens these gains. Our objective was to understand the vulnerability of protected areas and small patches of neotropical forest to fire in the Paraíba do Sul River Valley, Brazil, a region within the Atlantic …


Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda Jun 2020

Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda

Biology Faculty Publications and Presentations

Despite a critical need to evaluate effectiveness of forest treatments in improving stand health, practitioners lack quantitative, repeatable metrics to assess tree vigor and stand health. We evaluated canopy and whole tree attributes of ponderosa pine (Pinus ponderosa Dougl. Ex Laws) related to carbon balance, water balance, and susceptibility to insects and pathogens in dry, pine-dominated forest stands during a multi-year drought, an environmental challenge to stand resilience. Metrics of trees in two unmanaged, and seven treated forested stands, in both uplands and lowlands to develop the quantitative approach. Whole tree and crown attributes including needle length and color, branchlet …


Post-Fire Changes In Interior Alaska's Vegetation Composition, Jannike E. Allen May 2020

Post-Fire Changes In Interior Alaska's Vegetation Composition, Jannike E. Allen

University Honors Theses

Global warming is altering the fire regime of interior Alaska, which may have cascading effects on the prevalence of forest types and species dominance across this region. Our objective was to investigate the relationship between vegetation composition and fire in the boreal forest of interior Alaska. We utilized data from over 700 plots sampled across the landscape designated as the Tanana region by the US Forest Service for Forest Inventory Analysis (FIA), as well as fire history records. We compared biomass and stem density of conifer and hardwood forest types, as well as individual tree species, across a gradient of …


Modeling Post-Fire Successional Trajectories Under Climate Change In Interior Alaska Using Landis Ii, Shelby A. Weiss Feb 2020

Modeling Post-Fire Successional Trajectories Under Climate Change In Interior Alaska Using Landis Ii, Shelby A. Weiss

Systems Science Friday Noon Seminar Series

Alaska boreal forest ecosystems are experiencing a greater frequency of wildfire relative to the region’s historic fire regime. These increases in fire frequency, as well as annual burned area, increase the probability of forests re-burning within shorter intervals than were experienced historically. Such changes to the fire regime have the potential to shift successional trajectories in this ecosystem. To better understand potential changes in vegetation composition following short-interval, repeat fires, we are using LANDIS-II, a forest landscape model, to simulate changes in forest composition in response to climate change and increasing fire frequency. This seminar will include a description of …


Hydrochorous Seed Dispersal In Riparian Forests Altered By Urbanization, Christa Von Behren, J. Alan Yeakley Jan 2020

Hydrochorous Seed Dispersal In Riparian Forests Altered By Urbanization, Christa Von Behren, J. Alan Yeakley

Environmental Science and Management Faculty Publications and Presentations

While riparian habitat alterations from urban stream syndrome are known to affect vegetation establishment and survival, the degree to which riparian seed delivery by hydrochory is affected by urbanization is unclear. We hypothesized that (1) there would be a reduction in the overall number of seeds deposited by streams as watershed urbanization increased; and (2) in the most urbanized watersheds, seeds deposited by water would be predominantly from species with traits favoring dispersal in general, including tall stature and high seed production, and favoring deposition by water in particular, including large seed size and the presence of a dispersal appendage. …