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• 21. [Article] Prospective Elementary Mathematics Teacher Content Knowledge: An Introduction

  This Special Issue on the mathematical content knowledge of prospective elementary teachers (PTs) provides summaries of the extant peer-­‐reviewed research literature from 1978 to 2012 on PTs’ content ...

  Citation × Citation Citation Abstract Copy Title: Prospective Elementary Mathematics Teacher Content Knowledge: An Introduction Author: Browning, Christine, Thanheiser, Eva, Edson, Alden, Kimani, Patrick M, Olanoff, Dana, Tobias, Jennifer M., Whitacre, Ian Year: 2014 This Special Issue on the mathematical content knowledge of prospective elementary teachers (PTs) provides summaries of the extant peer-­‐reviewed research literature from 1978 to 2012 on PTs’ content knowledge across several mathematical topics, specifically whole number and operations, fractions, decimals, geometry and measurement, and algebra. Each topic-­‐specific summary of the literature is presented in a self-­‐contained paper, written by a subgroup of a larger Working Group that has collaborated across several years, resulting in this Special Issue sharing the final work. The authors hope this summative look at prospective teacher content knowledge will be of interest to the mathematics education community and will be a useful resource when considering future research as well as designing mathematics content courses for prospective elementary teachers. The following sections in this issue provide background information on our overarching framework for the mathematical content knowledge of prospective elementary teachers as well as our rationale for conducting the summary of research. We briefly describe the intent and history of the Working Group that conducted the summaries, followed by the methods utilized in the summary process. Finally, we provide a description of what follows in each subsequent paper and close with our intentions of how this Special Issue might be used by our readers Title: Prospective Elementary Mathematics Teacher Content Knowledge: An Introduction Author: Browning, Christine, Thanheiser, Eva, Edson, Alden, Kimani, Patrick M, Olanoff, Dana, Tobias, Jennifer M., Whitacre, Ian Year: 2014 This Special Issue on the mathematical content knowledge of prospective elementary teachers (PTs) provides summaries of the extant peer-­‐reviewed research literature from 1978 to 2012 on PTs’ content knowledge across several mathematical topics, specifically whole number and operations, fractions, decimals, geometry and measurement, and algebra. Each topic-­‐specific summary of the literature is presented in a self-­‐contained paper, written by a subgroup of a larger Working Group that has collaborated across several years, resulting in this Special Issue sharing the final work. The authors hope this summative look at prospective teacher content knowledge will be of interest to the mathematics education community and will be a useful resource when considering future research as well as designing mathematics content courses for prospective elementary teachers. The following sections in this issue provide background information on our overarching framework for the mathematical content knowledge of prospective elementary teachers as well as our rationale for conducting the summary of research. We briefly describe the intent and history of the Working Group that conducted the summaries, followed by the methods utilized in the summary process. Finally, we provide a description of what follows in each subsequent paper and close with our intentions of how this Special Issue might be used by our readers Close

• 22. [Article] A Family-Friendly Study Room for Student-Parents and Their Children at Portland State University Library

  The article focuses on the history and use of the Family Study Room at Portland State University Library.

  Citation × Citation Citation Abstract Copy Title: A Family-Friendly Study Room for Student-Parents and Their Children at Portland State University Library Author: Petit, Joan Year: 2014 The article focuses on the history and use of the Family Study Room at Portland State University Library. Title: A Family-Friendly Study Room for Student-Parents and Their Children at Portland State University Library Author: Petit, Joan Year: 2014 The article focuses on the history and use of the Family Study Room at Portland State University Library. Close

• 23. [Article] Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington

  The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller ...

  Citation × Citation Citation Abstract Copy Title: Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington Author: Van Glubt, Sarah, Wells, Scott A., Berger, Chris J. Year: 2017 The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller creeks, five wastewater treatment plants, and groundwater discharge to the Chehalis River. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure’s impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed for the years 2013 and 2014. Once calibration was complete, model scenarios for future climate conditions and dam operating regimes were conducted. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. Title: Hydrodynamic and Water Quality Modeling of the Chehalis River in Washington Author: Van Glubt, Sarah, Wells, Scott A., Berger, Chris J. Year: 2017 The Chehalis River Basin is located in the southwest region of Washington and is over 125 miles long flowing through agricultural, residential, industrial, and forest land. Four major rivers, many smaller creeks, five wastewater treatment plants, and groundwater discharge to the Chehalis River. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure’s impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed for the years 2013 and 2014. Once calibration was complete, model scenarios for future climate conditions and dam operating regimes were conducted. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. Close

• 24. [Article] Genomics-Informed Isolation and Characterization of a Symbiotic Nanoarchaeota System from a Terrestrial Geothermal Environment

  Biological features can be inferred, based on genomic data, for many microbial lineages that remain uncultured. However, cultivation is important for characterizing an organism’s physiology and testing ...

  Citation × Citation Citation Abstract Copy Title: Genomics-Informed Isolation and Characterization of a Symbiotic Nanoarchaeota System from a Terrestrial Geothermal Environment Author: Wurch, Louie, Giannone, Richard J., Belisle, Bernard S., Swift, Carolyn, Utturkar, Sagar, Hettich, Robert L., Reysenbach, Anna-Louise, Podar, Mircea Year: 2016 Biological features can be inferred, based on genomic data, for many microbial lineages that remain uncultured. However, cultivation is important for characterizing an organism’s physiology and testing its genome-encoded potential. Here we use single-cell genomics to infer cultivation conditions for the isolation of an ectosymbiotic Nanoarchaeota (‘Nanopusillus acidilobi’) and its host (Acidilobus, a crenarchaeote) from a terrestrial geothermal environment. The cells of ‘Nanopusillus’ are among the smallest known cellular organisms (100–300 nm). They appear to have a complete genetic information processing machinery, but lack almost all primary biosynthetic functions as well as respiration and ATP synthesis. Genomic and proteomic comparison with its distant relative, the marine Nanoarchaeum equitans illustrate an ancient, common evolutionary history of adaptation of the Nanoarchaeota to ectosymbiosis, so far unique among the Archaea. Title: Genomics-Informed Isolation and Characterization of a Symbiotic Nanoarchaeota System from a Terrestrial Geothermal Environment Author: Wurch, Louie, Giannone, Richard J., Belisle, Bernard S., Swift, Carolyn, Utturkar, Sagar, Hettich, Robert L., Reysenbach, Anna-Louise, Podar, Mircea Year: 2016 Biological features can be inferred, based on genomic data, for many microbial lineages that remain uncultured. However, cultivation is important for characterizing an organism’s physiology and testing its genome-encoded potential. Here we use single-cell genomics to infer cultivation conditions for the isolation of an ectosymbiotic Nanoarchaeota (‘Nanopusillus acidilobi’) and its host (Acidilobus, a crenarchaeote) from a terrestrial geothermal environment. The cells of ‘Nanopusillus’ are among the smallest known cellular organisms (100–300 nm). They appear to have a complete genetic information processing machinery, but lack almost all primary biosynthetic functions as well as respiration and ATP synthesis. Genomic and proteomic comparison with its distant relative, the marine Nanoarchaeum equitans illustrate an ancient, common evolutionary history of adaptation of the Nanoarchaeota to ectosymbiosis, so far unique among the Archaea. Close

• 25. [Article] What's On Your Mind? : A Generational Comparison of Language Use on Online Social Networking Platforms

  This thesis explores the connections between user age and unique linguistic features used when communicating on Facebook and other online social networking platforms, in the form of a literature review. ...

  Citation × Citation Citation Abstract Copy Title: What's On Your Mind? : A Generational Comparison of Language Use on Online Social Networking Platforms Author: Stidham, Samantha Year: 2014 This thesis explores the connections between user age and unique linguistic features used when communicating on Facebook and other online social networking platforms, in the form of a literature review. It includes a detailed history of computer-mediated communication, along with an analysis of all of Facebook’s features and how they contribute to communication via the site. The language features common to each age group (young adults/teens, adults, and seniors) are detailed, analyzed from Schwartz et al’s work Personality, gender, and age in the language of social media: The Open-Vocabulary Approach, along with making the argument that teens and seniors—the two most disparate groups using online social networking platforms today—are so different due to Prensky’s concepts of “digital native” and “digital adopter.” Title: What's On Your Mind? : A Generational Comparison of Language Use on Online Social Networking Platforms Author: Stidham, Samantha Year: 2014 This thesis explores the connections between user age and unique linguistic features used when communicating on Facebook and other online social networking platforms, in the form of a literature review. It includes a detailed history of computer-mediated communication, along with an analysis of all of Facebook’s features and how they contribute to communication via the site. The language features common to each age group (young adults/teens, adults, and seniors) are detailed, analyzed from Schwartz et al’s work Personality, gender, and age in the language of social media: The Open-Vocabulary Approach, along with making the argument that teens and seniors—the two most disparate groups using online social networking platforms today—are so different due to Prensky’s concepts of “digital native” and “digital adopter.” Close

• 26. [Article] Relative Sea-Level Trends in New York City During the Past 1500 Years

  New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and ...

  Citation × Citation Citation Abstract Copy Title: Relative Sea-Level Trends in New York City During the Past 1500 Years Author: Kemp, Andrew C., Hill, Troy D., Vane, Christopher H., Cahill, Niamh, Orton, Philip, Talke, Stefan A., Parnell, Andrew C., Sanborn, Kelsey, Hartig, Ellen Year: 2017 New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ13C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen profiles. The reconstruction was generated within a Bayesian hierarchical model to accommodate multiple proxies and to provide a unified statistical framework for quantifying uncertainty. We show that RSL in NYC rose by ~1.70 m since ~575 CE (including ~0.38 m since 1850 CE). The rate of RSL rise increased markedly at 1812–1913 CE from ~1.0 to ~2.5 mm/yr, which coincides with other reconstructions along the US Atlantic coast. We investigated the possible influence of tidal-range change in Long Island Sound on our reconstruction using a regional tidal model, and we demonstrate that this effect was likely small. However, future tidal-range change could exacerbate the impacts of RSL rise in communities bordering Long Island Sound. The current rate of RSL rise is the fastest that NYC has experienced for >1500 years, and its ongoing acceleration suggests that projections of 21st-century local RSL rise will be realized. Title: Relative Sea-Level Trends in New York City During the Past 1500 Years Author: Kemp, Andrew C., Hill, Troy D., Vane, Christopher H., Cahill, Niamh, Orton, Philip, Talke, Stefan A., Parnell, Andrew C., Sanborn, Kelsey, Hartig, Ellen Year: 2017 New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ13C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen profiles. The reconstruction was generated within a Bayesian hierarchical model to accommodate multiple proxies and to provide a unified statistical framework for quantifying uncertainty. We show that RSL in NYC rose by ~1.70 m since ~575 CE (including ~0.38 m since 1850 CE). The rate of RSL rise increased markedly at 1812–1913 CE from ~1.0 to ~2.5 mm/yr, which coincides with other reconstructions along the US Atlantic coast. We investigated the possible influence of tidal-range change in Long Island Sound on our reconstruction using a regional tidal model, and we demonstrate that this effect was likely small. However, future tidal-range change could exacerbate the impacts of RSL rise in communities bordering Long Island Sound. The current rate of RSL rise is the fastest that NYC has experienced for >1500 years, and its ongoing acceleration suggests that projections of 21st-century local RSL rise will be realized. Close

• 27. [Article] Rewriting History: Using Reconciliation Processes to Revise Dominant Cultural Narratives and Assessing Cultural Readiness for Reconciliation

  Truth and Reconciliation processes are key to rebuilding societies damaged by broad-based, government-sanctioned violence by revising dominant cultural narratives of the violence. In Indonesia, there has ...

  Citation × Citation Citation Abstract Copy Title: Rewriting History: Using Reconciliation Processes to Revise Dominant Cultural Narratives and Assessing Cultural Readiness for Reconciliation Author: Mack, Flannery Year: 2016 Truth and Reconciliation processes are key to rebuilding societies damaged by broad-based, government-sanctioned violence by revising dominant cultural narratives of the violence. In Indonesia, there has been no such process following the killings of between 500,000 and 2 million suspected communists in 1965-66. This paper is an exploration of conflict transformation theory, and of what form a truth and reconciliation process might take in Indonesia following 50 years of impunity. Using Joshua Oppenheimer's 2012 and 2014 documentaries The Act of Killing and The Look of Silence as primary reference points, I use critical discourse analysis to look at how the dominant narrative of the killings is upheld and discursively constructed, and at what counter-narratives might be emerging that could give rise to conflict transformation and reconciliation. I ultimately offer an assessment of the readiness to take on such a process, based on analysis of the films and other contextual materials, including journalism and official documents regarding the killings. Title: Rewriting History: Using Reconciliation Processes to Revise Dominant Cultural Narratives and Assessing Cultural Readiness for Reconciliation Author: Mack, Flannery Year: 2016 Truth and Reconciliation processes are key to rebuilding societies damaged by broad-based, government-sanctioned violence by revising dominant cultural narratives of the violence. In Indonesia, there has been no such process following the killings of between 500,000 and 2 million suspected communists in 1965-66. This paper is an exploration of conflict transformation theory, and of what form a truth and reconciliation process might take in Indonesia following 50 years of impunity. Using Joshua Oppenheimer's 2012 and 2014 documentaries The Act of Killing and The Look of Silence as primary reference points, I use critical discourse analysis to look at how the dominant narrative of the killings is upheld and discursively constructed, and at what counter-narratives might be emerging that could give rise to conflict transformation and reconciliation. I ultimately offer an assessment of the readiness to take on such a process, based on analysis of the films and other contextual materials, including journalism and official documents regarding the killings. Close

• 28. [Article] Ecological Investigations to Select Mitigation Options to Reduce Vehicle-Caused Mortality of a Threatened Butterfly

  Whereas roads that bisect habitat are known to decrease population size through animal-vehicle collisions or interruption of key life history events, it is not always obvious how to reduce such impacts, ...

  Citation × Citation Citation Abstract Copy Title: Ecological Investigations to Select Mitigation Options to Reduce Vehicle-Caused Mortality of a Threatened Butterfly Author: Zielin, Sara B., Littlejohn, Jalene, de Rivera, Catherine E., Smith, Winston P., Jacobson, Sandra L. Year: 2016 Whereas roads that bisect habitat are known to decrease population size through animal-vehicle collisions or interruption of key life history events, it is not always obvious how to reduce such impacts, especially for flying organisms. We needed a quick, cost-efficient and effective way to determine how best to decrease vehicle-caused mortality while maintaining habitat connectivity for the federally listed Oregon silverspot butterfly, Speyeria zerene hippolyta. Therefore, we gathered targeted ecological information that informed selection of a mitigation option prior to implementation. We sampled butterfly behavior and environmental conditions along a highway and conducted a small-scale experiment along a decommissioned road corridor used by these butterflies. Using our findings, we recommended vegetation management and helped managers eliminate options they were considering that would be ineffective such as increasing shade or wind in the road, and installing fencing or hedgerows aimed at directing flight above traffic. This quick and inexpensive approach of using ecological observations and small-scale experiments to evaluate the likely success of each available mitigation option can be used to determine effective, species-specific solutions for reducing traffic impacts on pollinators and other small, flying organisms of conservation concern. Title: Ecological Investigations to Select Mitigation Options to Reduce Vehicle-Caused Mortality of a Threatened Butterfly Author: Zielin, Sara B., Littlejohn, Jalene, de Rivera, Catherine E., Smith, Winston P., Jacobson, Sandra L. Year: 2016 Whereas roads that bisect habitat are known to decrease population size through animal-vehicle collisions or interruption of key life history events, it is not always obvious how to reduce such impacts, especially for flying organisms. We needed a quick, cost-efficient and effective way to determine how best to decrease vehicle-caused mortality while maintaining habitat connectivity for the federally listed Oregon silverspot butterfly, Speyeria zerene hippolyta. Therefore, we gathered targeted ecological information that informed selection of a mitigation option prior to implementation. We sampled butterfly behavior and environmental conditions along a highway and conducted a small-scale experiment along a decommissioned road corridor used by these butterflies. Using our findings, we recommended vegetation management and helped managers eliminate options they were considering that would be ineffective such as increasing shade or wind in the road, and installing fencing or hedgerows aimed at directing flight above traffic. This quick and inexpensive approach of using ecological observations and small-scale experiments to evaluate the likely success of each available mitigation option can be used to determine effective, species-specific solutions for reducing traffic impacts on pollinators and other small, flying organisms of conservation concern. Close

• 29. [Article] Prospectus for Future Research: Temperature Effects on Green Macroalgae

  Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and ...

  Citation × Citation Citation Abstract Copy Title: Prospectus for Future Research: Temperature Effects on Green Macroalgae Author: Gonzalez Pelayo, Ana Year: 2016 Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and animals on land and in oceans. The research being conducted looks at how these temperature changes affect the anatomy and physiology of organisms, but other research also studies how terrestrial and aquatic ecosystems have changed and the types of responses that have occurred as a result. For many years, research in terrestrial ecosystems has dominated research in aquatic ecosystems. Limited research has been conducted in aquatic ecosystems involving green macroalgae, which are primary producers and an essential part of these ecosystems. Within the last fifteen years, research regarding the effects of temperature change on green macroalgae has shown that temperature affects photosynthesis and biochemistry. Overall, photosynthesis is almost completely inhibited after sufficient exposure due to damage in Photosystem II. There is also a substantial change in the production of chemical molecules known as reactive oxygen species that caused physical damage to the algal cells as well as a change in structure for proteins that is essential for function. I reviewed the literature within the past fifteen years, regarding the effects of temperature on a variety of green macroalgae species. The results indicated that after sufficient exposure, the photosynthetic rate of macroalgae is reduced significantly and that the change in chemistry lead to alterations in the physiology of green macroalgae. In this thesis, I propose two possible directions for algae research that involves genetic sequencing of a model species to identify a possible temperature tolerance gene, as well as the potential use of green macroalgae in photobioreactors as a source of renewable energy. Title: Prospectus for Future Research: Temperature Effects on Green Macroalgae Author: Gonzalez Pelayo, Ana Year: 2016 Research on temperature change has received attention from scientists. Not only has temperature change attracted scientists who study the Earth’s weather and climate, but also those who study plants and animals on land and in oceans. The research being conducted looks at how these temperature changes affect the anatomy and physiology of organisms, but other research also studies how terrestrial and aquatic ecosystems have changed and the types of responses that have occurred as a result. For many years, research in terrestrial ecosystems has dominated research in aquatic ecosystems. Limited research has been conducted in aquatic ecosystems involving green macroalgae, which are primary producers and an essential part of these ecosystems. Within the last fifteen years, research regarding the effects of temperature change on green macroalgae has shown that temperature affects photosynthesis and biochemistry. Overall, photosynthesis is almost completely inhibited after sufficient exposure due to damage in Photosystem II. There is also a substantial change in the production of chemical molecules known as reactive oxygen species that caused physical damage to the algal cells as well as a change in structure for proteins that is essential for function. I reviewed the literature within the past fifteen years, regarding the effects of temperature on a variety of green macroalgae species. The results indicated that after sufficient exposure, the photosynthetic rate of macroalgae is reduced significantly and that the change in chemistry lead to alterations in the physiology of green macroalgae. In this thesis, I propose two possible directions for algae research that involves genetic sequencing of a model species to identify a possible temperature tolerance gene, as well as the potential use of green macroalgae in photobioreactors as a source of renewable energy. Close

• 30. [Article] Variation in Green Roof Storage Capacity, Associated Drivers, and Implications for Stormwater Management in Portland, Oregon

  Greens roofs, also known as ecoroofs or living roofs, provide numerous ecosystem services and are becoming widely integrated into urban stormwater management systems. Despite a long and robust history ...

  Citation × Citation Citation Abstract Copy Title: Variation in Green Roof Storage Capacity, Associated Drivers, and Implications for Stormwater Management in Portland, Oregon Author: Estrella, Melecio Year: 2016 Greens roofs, also known as ecoroofs or living roofs, provide numerous ecosystem services and are becoming widely integrated into urban stormwater management systems. Despite a long and robust history of green roof projects in Portland, Oregon, there is a distinct lack of research on in situ performance. This thesis addressed this gap by investigating the hydrologic performance of five green roofs in Portland for a time period spanning November through February. Despite difficulty with the sensor calibrations, our analysis of moisture content data from these roofs revealed variation in: (1) total evapotranspiration, which serves as a proxy for total stormwater retention, and (2) storage capacity, which was defined as the difference between average maximum and minimum substrate volumetric water content measured under field conditions. Evapotranspiration was predicted by storage capacity following first order growth using non-linear regression analysis, suggesting that increasing storage capacity should correspond with increases in evapotranspiration and retention up until an inflection point of possibly 8-9mm beyond which the effect diminishes. Storage capacity was further shown to be correlated with substrate properties such as organic matter content and coefficient of curvature. Finally, retention values of 13.4% - 32.8% for Portland’s rainy season in 2015-2016 were found to be substantially lower than optimal annual values reported in other studies in Portland as well as cities around the world. This suggests that Portland’s green roofs may not perform as well as expected during months of high precipitation, which are the times when hydrologic performance is most critical. Further research should consider seasonal green roof performance in the Pacific Northwest and also revisit storage capacity as a parameter to include in future design standards. Title: Variation in Green Roof Storage Capacity, Associated Drivers, and Implications for Stormwater Management in Portland, Oregon Author: Estrella, Melecio Year: 2016 Greens roofs, also known as ecoroofs or living roofs, provide numerous ecosystem services and are becoming widely integrated into urban stormwater management systems. Despite a long and robust history of green roof projects in Portland, Oregon, there is a distinct lack of research on in situ performance. This thesis addressed this gap by investigating the hydrologic performance of five green roofs in Portland for a time period spanning November through February. Despite difficulty with the sensor calibrations, our analysis of moisture content data from these roofs revealed variation in: (1) total evapotranspiration, which serves as a proxy for total stormwater retention, and (2) storage capacity, which was defined as the difference between average maximum and minimum substrate volumetric water content measured under field conditions. Evapotranspiration was predicted by storage capacity following first order growth using non-linear regression analysis, suggesting that increasing storage capacity should correspond with increases in evapotranspiration and retention up until an inflection point of possibly 8-9mm beyond which the effect diminishes. Storage capacity was further shown to be correlated with substrate properties such as organic matter content and coefficient of curvature. Finally, retention values of 13.4% - 32.8% for Portland’s rainy season in 2015-2016 were found to be substantially lower than optimal annual values reported in other studies in Portland as well as cities around the world. This suggests that Portland’s green roofs may not perform as well as expected during months of high precipitation, which are the times when hydrologic performance is most critical. Further research should consider seasonal green roof performance in the Pacific Northwest and also revisit storage capacity as a parameter to include in future design standards. Close