Search

Search Results

• 1. [Article] The subtidal Bryozoan fauna off Cape Arago, Oregon

  83 pages

  Citation × Citation Citation Abstract Copy Title: The subtidal Bryozoan fauna off Cape Arago, Oregon Author: Cottrell, Dylan Year: 2017, 2013 83 pages Title: The subtidal Bryozoan fauna off Cape Arago, Oregon Author: Cottrell, Dylan Year: 2017, 2013 83 pages Close

• 2. [Article] The Effects of Global Changes on Fungal Communities: Measuring Biodiversity Belowground

  Global changes resulting from human activities, including elevated levels of greenhouse gases, enrichment of nitrogen and land use changes, have led to substantial losses in biodiversity of macroscopic ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Global Changes on Fungal Communities: Measuring Biodiversity Belowground Author: Mueller, Rebecca Year: 2013, 2014 Global changes resulting from human activities, including elevated levels of greenhouse gases, enrichment of nitrogen and land use changes, have led to substantial losses in biodiversity of macroscopic organisms, such as plants and animals, but whether these changes will have similar impacts on microscopic organisms, such as bacteria and fungi, is less clear. I examined the impact of three of these global changes, including elevated carbon dioxide, increased soil nitrogen availability and large-scale deforestation, on the biodiversity of soil fungi in three separate ecosystems. The responses of fungi to global changes were variable across ecosystems and the experimental system and were not readily predicted by observed changes in the plant community. However, subtle shifts in the community composition of fungi were observed in response to all global changes. Whether these shifts will impact the ecosystem function of these systems in unclear, but previous studies suggest that even small changes in community dynamics can have large effects on important processes, such as nitrogen cycling and carbon storage. These findings indicate that soil fungi do respond to global changes, but additional research must be undertaken to examine the effects of these shifts. Title: The Effects of Global Changes on Fungal Communities: Measuring Biodiversity Belowground Author: Mueller, Rebecca Year: 2013, 2014 Global changes resulting from human activities, including elevated levels of greenhouse gases, enrichment of nitrogen and land use changes, have led to substantial losses in biodiversity of macroscopic organisms, such as plants and animals, but whether these changes will have similar impacts on microscopic organisms, such as bacteria and fungi, is less clear. I examined the impact of three of these global changes, including elevated carbon dioxide, increased soil nitrogen availability and large-scale deforestation, on the biodiversity of soil fungi in three separate ecosystems. The responses of fungi to global changes were variable across ecosystems and the experimental system and were not readily predicted by observed changes in the plant community. However, subtle shifts in the community composition of fungi were observed in response to all global changes. Whether these shifts will impact the ecosystem function of these systems in unclear, but previous studies suggest that even small changes in community dynamics can have large effects on important processes, such as nitrogen cycling and carbon storage. These findings indicate that soil fungi do respond to global changes, but additional research must be undertaken to examine the effects of these shifts. Close

• 3. [Article] Microbial Biodiversity of the Atmosphere

  Microorganisms are critical to the functioning of terrestrial and aquatic ecosystems and may also play a role in the functioning of the atmosphere. However, little is known about the diversity and function ...

  Citation × Citation Citation Abstract Copy Title: Microbial Biodiversity of the Atmosphere Author: Klein, Ann Year: 2016 Microorganisms are critical to the functioning of terrestrial and aquatic ecosystems and may also play a role in the functioning of the atmosphere. However, little is known about the diversity and function of microorganisms in the atmosphere. To investigate the forces driving the assembly of bacterial microbial communities in the atmosphere, I measured temporal variation in bacterial diversity and composition over diurnal and inter-day time scales. Results suggest that bacterial communities in the atmosphere markedly vary over diurnal time scales and are likely structured by inputs from both local terrestrial and long-distance sources. To assess the potential functions of bacteria and fungi in the atmosphere, I characterized total and potentially active communities using both RNA- and DNA-based data. Results suggest there are metabolically active microorganisms in the atmosphere that may affect atmospheric functions including precipitation development and carbon cycling. This dissertation includes previously published and unpublished co-authored material. Title: Microbial Biodiversity of the Atmosphere Author: Klein, Ann Year: 2016 Microorganisms are critical to the functioning of terrestrial and aquatic ecosystems and may also play a role in the functioning of the atmosphere. However, little is known about the diversity and function of microorganisms in the atmosphere. To investigate the forces driving the assembly of bacterial microbial communities in the atmosphere, I measured temporal variation in bacterial diversity and composition over diurnal and inter-day time scales. Results suggest that bacterial communities in the atmosphere markedly vary over diurnal time scales and are likely structured by inputs from both local terrestrial and long-distance sources. To assess the potential functions of bacteria and fungi in the atmosphere, I characterized total and potentially active communities using both RNA- and DNA-based data. Results suggest there are metabolically active microorganisms in the atmosphere that may affect atmospheric functions including precipitation development and carbon cycling. This dissertation includes previously published and unpublished co-authored material. Close

• 4. [Article] Essays on the Recreational Value of Avian Biodiversity

  This dissertation uses a convenience sample of members of eBird, a large citizen science project maintained by the Cornell University's Laboratory of Ornithology, to explore the value of avian biodiversity ...

  Citation × Citation Citation Abstract Copy Title: Essays on the Recreational Value of Avian Biodiversity Author: Kolstoe, Sonja Year: 2016 This dissertation uses a convenience sample of members of eBird, a large citizen science project maintained by the Cornell University's Laboratory of Ornithology, to explore the value of avian biodiversity to bird watchers. Panel data (i.e. longitudinal data) are highly desirable for preference estimation. Fortuitously, the diaries of birding excursions by eBird members provide a rich source of spatial data on trips taken, over time by the same individuals, to a variety of birding destinations. Origin and destination data can be combined with exogenous species prevalence information. These combined data sources permit estimation of utility-theoretic choice models that allow derivation of the marginal utilities of avian biodiversity measures as well as the marginal utility of net income (i.e. consumption of other goods and services). Ratios of these marginal utilities yield marginal willingness to pay (MWTP) estimates for numbers of bird species (or numbers of species of different types, in richer specifications). MWTP for levels of other attributes of birding destinations are also derived (e.g. ecosystem type, management regime, seasonal variations, a time trend).\\ The chapters are organized as follows: Chapter 2 is a stand-alone paper that demonstrates the feasibility of a travel-cost based random utility model with the eBird data. This chapter focuses on measuring the total number of bird species at each birding hotspot in Washington and Oregon states. This chapter does not differentiate among types of birders beyond using their recent birding activities in an analysis of habit formation or variety-seeking behavior. For this model, beyond past behavior, a representative consumer is postulated. Chapter 3 starts from the basic specifications identified in Chapter 2 and explores heterogeneous preferences among consumers as well as their preferences for species richness and for different categories of birds. This chapter explores whether different types of birds are relatively more attractive to different types of birders (for example, by gender or by age or by neighborhood characteristics and educational attainment). Chapter 4 is an extension of the work in Chapter 3 to explore how changing site attributes in the face of climate change effects birder welfare. This dissertation includes previously unpublished co-authored material. Title: Essays on the Recreational Value of Avian Biodiversity Author: Kolstoe, Sonja Year: 2016 This dissertation uses a convenience sample of members of eBird, a large citizen science project maintained by the Cornell University's Laboratory of Ornithology, to explore the value of avian biodiversity to bird watchers. Panel data (i.e. longitudinal data) are highly desirable for preference estimation. Fortuitously, the diaries of birding excursions by eBird members provide a rich source of spatial data on trips taken, over time by the same individuals, to a variety of birding destinations. Origin and destination data can be combined with exogenous species prevalence information. These combined data sources permit estimation of utility-theoretic choice models that allow derivation of the marginal utilities of avian biodiversity measures as well as the marginal utility of net income (i.e. consumption of other goods and services). Ratios of these marginal utilities yield marginal willingness to pay (MWTP) estimates for numbers of bird species (or numbers of species of different types, in richer specifications). MWTP for levels of other attributes of birding destinations are also derived (e.g. ecosystem type, management regime, seasonal variations, a time trend).\\ The chapters are organized as follows: Chapter 2 is a stand-alone paper that demonstrates the feasibility of a travel-cost based random utility model with the eBird data. This chapter focuses on measuring the total number of bird species at each birding hotspot in Washington and Oregon states. This chapter does not differentiate among types of birders beyond using their recent birding activities in an analysis of habit formation or variety-seeking behavior. For this model, beyond past behavior, a representative consumer is postulated. Chapter 3 starts from the basic specifications identified in Chapter 2 and explores heterogeneous preferences among consumers as well as their preferences for species richness and for different categories of birds. This chapter explores whether different types of birds are relatively more attractive to different types of birders (for example, by gender or by age or by neighborhood characteristics and educational attainment). Chapter 4 is an extension of the work in Chapter 3 to explore how changing site attributes in the face of climate change effects birder welfare. This dissertation includes previously unpublished co-authored material. Close

• 5. [Article] Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk

  78 pages. Examining committee chair:David Hulse

  Citation × Citation Citation Abstract Copy Title: Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk Author: Lewis, Alison Year: 2016 78 pages. Examining committee chair:David Hulse Title: Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk Author: Lewis, Alison Year: 2016 78 pages. Examining committee chair:David Hulse Close