Social and Behavioral Sciences Commons^™

Long-Term Variation Of Summer Phytoplankton Communities In An Urban Lake In Relation To Lake Management And Climate Conditions, Yuan Xiao Grund

Dissertations and Theses

Eutrophication is one of the primary factors causing harmful cyanobacteria blooms in freshwater lakes; climate change such as warmer temperature can potentially further increase both frequency and intensity of blooms. This study investigated the long-term changes in water quality and summer phytoplankton assemblages in Oswego Lake, OR, in relation to lake management practices (e.g., hypolimnetic aeration and alum treatments), as well as climatic and regional meteorological conditions. Both water quality and phytoplankton assemblages were sampled biweekly during summer seasons between 2001 and 2013. The concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP) and total nitrogen (TN) decreased 66%, 93% …

Lone Wolves And Copycats: Assessing Policy And Infrastructure For Flood Hazard And Floodplain Management, Samantha L. Hamlin

Dissertations and Theses

To mitigate flood hazard, which affects millions of people every year, increasing numbers of communities are developing green infrastructure policies to not only mitigate the hazard, but to meet other community policy objectives, as green infrastructure is often cited for the multiple benefits it confers. To support the implementation of policies that help communities meet their policy objectives, however, it is imperative to understand how policy is innovated and adopted. To do so, I applied the internal determinants and regional diffusion models, what I refer to as the lone wolf and copycat models. In policy, a lone wolf innovates a …

Characterizing Temperature Variability States Across Southern South America And Associated Synoptic-Scale Meteorological Patterns, Judah Adam Detzer

Dissertations and Theses

The aim of this thesis is to understand spatiotemporal temperature variability in southern South America by identifying overarching temperature variability states and their associated synoptic-scale meteorological patterns. Further, the temporal frequency of occurrence of those temperature variability states is investigated as is the role of recurrent low-frequency modes of climate variability (El Niño Southern Oscillation and the Southern Annular Mode) on temperature variability. K-means cluster analysis is used to group all months during the period 1980-2015 into four primary categories for summer and winter separately. Monthly maps of temperature anomalies are provided as input to the k-means algorithm and the …

Assessing Spatiotemporal Stream Temperature Trends And Drivers Through Integrated Longitudinal Thermal Profiling And Stationary Data Logger Methodology On The Upper Chehalis River, Wa, Whitney Vonada

Dissertations and Theses

This study encompasses 25 kilometers of the Chehalis River in Washington, USA that currently has sections under a Total Maximum Daily Load (TMDL) plan for stream temperature impairments that exceed 18°C, a regulatory standard set at the time of the listing to protect salmonid spawning, rearing, and migration. Using information integrated from stationary data loggers (n=22) that collected stream temperature information from August 4-September 10, 2017, and longitudinal thermal profiling performed on July 29-30, August 4-5, and September 9-10, 2017, this study aimed to quantify the spatial distribution of stream temperature, evaluate relative consistencies of the riverine thermal regime over …

Removing Dams, Constructing Science: Watershed Restoration Through A Socio-Eco-Technical Systems Lens, Zbigniew Jakub Grabowski

Dissertations and Theses

Ecological conservation and restoration in the anthropocene must struggle with overlapping drivers of biodiversity and cultural loss; ruptures of the ecological environment mirror ruptures of human relationships with nature. And yet technology cannot remove humans from nature; technological and infrastructural reconfigurations of nature create new vulnerabilities and risks for humans and ecosystems alike. How can conservation and restoration science productively grapple with complex infrastructure systems and decision-making processes as biophysical and social drivers of ecosystem change?

Using dam removals in the USA and in the Mid Columbia River region of the Pacific Northwest, this dissertation develops a conceptual framework for …

Waste Stream And Green Purchasing Analysis At Bonneville Lock And Dam, Alexander Bienko

Environmental Science and Management Professional Master's Project Reports

The United States Army Corps of Engineers (USACE), Portland District, has jurisdiction on three locks and four dams in the Columbia River basin. These sites "contribute to a water resource management system that provides flood risk management, power generation, water quality improvement, fish and wildlife habitat and recreation on the Columbia River and some of its tributaries". The Bonneville Lock and Dam (Bonneville Project) site lies on the Columbia River approximately 40 miles east from Portland, Oregon. Portions of the site have been declared a National Historic Landmark, from its origins in President Franklin D. Roosevelt's New Deal program from …

Nadaka 2023 Management Plan, Andrea Hurzeler

Environmental Science and Management Professional Master's Project Reports

Nadaka 2023 is a management plan written for Nadaka Nature Park that aims to assess current conditions, define desired future conditions, and make recommendations to achieve those desired future conditions. Nadaka Nature Park is a publically owned nature area and park space located in the Wilkes East Neighborhood and bordering the Rockwood Neighborhood of Gresham, Oregon. Originally owned by the Camp Fire Organization, Nadaka was purchased in 1995 by the City of Gresham and opened to the public in 2001. Making up Nadaka is a 10 acre nature area and a 2 acre park space. The nature area consists of …

The Silencing Power Of Algorithms: How The Facebook News Feed Algorithm Manipulates Users' Perceptions Of Opinion Climates, Callie Jessica Morgan

University Honors Theses

This extended literature review investigates how the architecture and features of the Facebook Newsfeed algorithm, EdgeRank, can inhibit and facilitate the expression of political opinions. This paper will investigate how Elisabeth Noelle-Neumann's theory on public opinion, Spiral of Silence, can be used to assess the Facebook news feed as a political opinion source that actively shapes users' perceptions of minority and majority opinion climates. The feedback loops created by the algorithm's criteria influences users' decisions to self-censor or express their political opinions with interpersonal connections and unfamiliar connections on the site.

The Dispute Over The Commons: Seed And Food Sovereignty As Decommodification In Chiapas, Mexico, Carol Frances HernáNdez RodríGuez

Dissertations and Theses

Seeds have become one of the most contested resources in our society. Control over seeds has intensified under neoliberalism, and today four large multinational corporations control approximately 70 percent of the global seed market. In response to this concentration of corporate power, an international social movement has emerged around the concept of seed sovereignty, which reclaims seeds and biodiversity as commons and public goods. This study examines the relationship between the global dynamics of commodification and enclosure of seeds, and the seed sovereignty countermovement for decommodification. I approach this analysis through an ethnographic case study of one local seed sovereignty …

Effects Of Beaver Dams On Urban Stream Hydraulic Response During Storm Events, Erin Poor

Environmental Science and Management Professional Master's Project Reports

Urbanization of landscapes alters watershed hydrology, leading to changes in the natural flow regime of local streams. Runoff from impervious surfaces and routing of stormwater can cause a rapid increase in the volume and velocity of streamflow. This is observed in the hydrograph as a steep rising limb, followed by a high peak, and a rapid falling limb. This rapidly varying streamflow, often referred to as flashiness, can increase erosive forces on the channel bed and banks, leading to channel incision and bank erosion. In areas where the hydrologic regime is less impacted by humans, beaver dams and ponds attenuate …

Glacier Inventories And Change In Glacier National Park, Melissa Carrie Brett

Dissertations and Theses

Glacier National Park, in northwestern Montana, is a unique and awe-inspiring national treasure that is often used by the media and public-at-large as a window into the effects of climate change. An updated inventory of glaciers and perennial snowfields (G&PS) in the Park, along with an assessment of their change over time, is essential to understanding the role that glaciers are playing in the environment of this Park. Nine inventories between 1966 and 2015 were compiled to assess area changes of G&PS. Over that 49-year period, total area changed by nearly -34 ± 11% between 1966 and 2015. Volume change, …

Assessing Effort Shifts And Familial Succession In Oregon’S Nearshore Fisheries, Bryn Ellen Hudson

Environmental Science and Management Professional Master's Project Reports

Since the industrial revolution, natural resource systems have rapidly modernized and globalized. Commercial fishing industries have expanded and optimized resource extraction but have often times exceeded sustainable levels of harvest. In the Pacific Northwestern United States, the commercial fishing industry is one of particular economic and cultural importance. Due to reduced yield of many native fish stocks, marine reserves have been implemented in Oregon’s nearshore waters in an effort to conserve biodiversity. While spatial closures of marine reserves seek to preserve and stabilize Oregon’s ocean ecosystems, adverse socioeconomic implications are inevitably created when profitable waters are set aside. A main …

Effects Of Variable Density Thinning On Spatial Patterns Of Overstory Trees In Mt. Hood National Forest, Emma Huston

Environmental Science and Management Professional Master's Project Reports

Variable density thinning (VDT) is a method of restoration thinning that attempts to increase ecosystem resilience and spatial heterogeneity in forest stands to more closely resemble mosaic-like patterns characteristic of late-successional forests, which consist of clusters of multiple trees, individual trees, and gaps. This study examines the spatial patterning of overstory trees resulting from VDT of conifer forests in Mt. Hood National Forest in the western Cascade Mountains and compares these patterns with reference conditions. Stem maps were created from field surveys of study plots within one mature stand and six thinned stands designated as Late-Successional Reserve (LSR) with varying …

Monitoring And Evaluating Malawi Youth Conservation Engagement After Community-Based Environmental Education Workshops, Stefanie Kramer

Environmental Science and Management Professional Master's Project Reports

This project addressed Peace Corps Malawi’s need to redevelop and implement environmental education workshops using a community-based approach, monitored project outcomes from these workshops, and provided an evaluation of strengths and areas for improvement of the environmental education workshop program.

Long-Term Managed Flooding To Control Invasive Phalaris Arundinacea L. And Help Restore Native Vegetation In An Urban Palustrine Wetlands Ecosystem, Robert P. Lascheck

Environmental Science and Management Professional Master's Project Reports

We sought to determine the effects of 13 years of hydrologic management on the wetland plant community in Smith and Bybee Wetlands Natural Area (SBW), an 809 ha palustrine wetland complex in north Portland, Oregon. Previous management efforts resulted in an altered hydrologic regime; historically high water levels in spring and low water levels in fall were replaced by persistent water levels with minimal annual variations. A water control structure was installed in 2003 to better approximate historic seasonal hydrologic changes to reduce invasive Phalaris arundinacea (reed canarygrass) cover and promote native wetland vegetation growth. Vegetation monitoring has been carried …