Forest Sciences Commons^™

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

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

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 …

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 …

Forests And Mental Health In South Africa: Panel Data Evidence, Dambala Gelo

Forest Collaborative Research

Slides from a presentation that examines the linkages between the green environment (urban forests, green open urban space) and mental health in South Africa. The author used representative panel data from the National Income Dynamics Survey, including the Center for Epidemiological Studies Short Depression Scale, to uncover these links.

The Community Economic Impacts Of Large Wildfires: A Case Study From Trinity County, California, Emily Jane Davis, Cassandra Moseley, Max Nielsen-Pincus, Pamela J. Jakes

Environmental Science and Management Faculty Publications and Presentations

Wildfires are increasing in severity and frequency in the American West, but there is limited understanding of their economic effects at the community level. We conducted a case study of the impacts of large wildfires in 2008 in Trinity County, California, by examining labor market, suppression spending, and qualitative interview data. We found that the 2008 fires had interrelated effects on several economic sectors in the county. Labor market data indicated a decrease in total private-sector employment and wages and an increase in public-sector employment and wages during the summer of 2008 compared to the previous year, while interviews captured …

The Effects Of Large Wildfires On Employment And Wage Growth And Volatility In The Western United States, Max Nielsen-Pincus, Cassandra Moseley, Krista Gebert

Environmental Science and Management Faculty Publications and Presentations

We examined the effect of large wildfires on economic growth and volatility in the western United States. We matched wildfire data with quarterly employment and earnings growth data to assess the specific effect of wildfire on employment and wage growth in western US counties. Wildfires generally tended to exhibit positive effects on employment and wage growth in the quarter(s) during which suppression efforts were active. However, this effect transitioned to increased economic volatility following a wildfire. The effect of wildfire also varied by the type of county in which wildfire occurred. The amount of suppression costs invested locally had the …

Job Growth And Loss Across Sectors And Time In The Western Us: The Impact Of Large Wildfires, Max Nielsen-Pincus, Cassandra Moseley, Krista Gebert

Environmental Science and Management Faculty Publications and Presentations

The link between economic growth and natural hazards has long been studied to better understand the effects of natural hazards on local, regional, and country level growth patterns. However, relatively little generalizable research has focused on wildfires, one of the most common forest disturbances in the western United States (US). We examined the effect of large wildfires on employment growth across sectors and time in the western US.We matched wildfire occurrences from 2004 to 2008 and their duration with monthly employment data to identify the effect of wildfire on employment growth. Wildfires generally tended to exhibit positive effects on employment …

The Role Of Wood Microsites At Timberline-Alpine Meadow Borders For Conifer Regeneration, Adelaide Chapman Johnson

Dissertations and Theses

This research aimed to determine whether wood microsites ("nurse logs"), which are regeneration sites in Pacific Northwest (PNW) subalpine forests, supported regeneration at timberline-alpine meadow borders. Upward advance of forests and conifer invasion into alpine meadows, which may be occurring in conjunction with climate warming, have gained worldwide attention. Successful alpine meadow seedling regeneration depends on suitable substrate availability, or microsites, for seedling establishment. To better understand factors associated with wood microsite occurrence, mechanisms of wood input were determined and four specific hypotheses were posed to assess: (1) seedling density and seedling survival; (2) growing season length, summer mean growing …

Understory Diversity And Succession On Coarse Woody Debris In A Coastal, Old-Growth Forest, Oregon, Shannon Lee Mcdonald

Dissertations and Theses

This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth, coastal forest. These forests are renowned for their high forest productivity, frequent wind storms, and slow log decomposition rates that produce unmatched accumulations of coarse woody debris (CWD) yet few studies have examined the relationship between CWD and understory vegetation ecology. My research addressed this topic by comparing understory plant census data between paired fallen log and forest floor sites (n=20 pairs). My objectives were to: 1) determine the influence of substrate type on community composition …

Evaluating The Effects Of Road Crossing Structures On Stream-Associated Amphibians In The Wilson River Watershed, Tillamook State Forest, Oregon, Sara Erin Twitchell

Dissertations and Theses

As replacement and removal of undersized culverts gains momentum as an effective technique for restoring natural stream flows and removing fish passage barriers, it is important to evaluate the benefits of these efforts on the in-stream and adjacent riparian habitat for other species of potential concern. This study compares stream-associated amphibian (SAA) occurrence in streams adjacent to different road crossing structures on unpaved forest roads in the Wilson River watershed located within the Tillamook State Forest, Oregon. Surveys were conducted at road crossing structures for three taxa of SAA; Pacific giant salamander (Dicamptodon tenebrosus), coastal tailed frog (Ascaphus truei), and …

Interview With Jeff Luebbers, Us Forest Service, 2010 (Audio), Jeff Luebbers

All Sustainability History Project Oral Histories

Interview of Jeff Luebbers by Chelsea Saurman on May 13th, 2010.

The interview index is available for download.

Street Trees In The Urban Forest Canopy: Portland, Oregon, Joseph Poracsky, David Banis

Geography Faculty Publications and Presentations

Attempts to identify the contribution of street trees to the overall urban forest of a city have been rare and lack consensus on how to measure that contribution – percentage of trees, percentage of canopy cover, or percentage of leaf area. The actual numeric values presented in the literature also vary over a broad range and often are based on estimates, extrapolations from aggregated data, or simply stated with no empirical data referenced. This study was undertaken to evaluate the contribution of street trees to canopy in Portland, Oregon. The study involved both visual and digital analysis of multi-band aerial …