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Theses/Dissertations

2021

Ecology and Evolutionary Biology

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Full-Text Articles in Life Sciences

Evaluating Avian Occupancy On Sites Treated With Nrcs Conservation Practices Implemented To Benefit Cerulean (Setophaga Cerulea) And Golden-Winged Warblers (Vermivora Chrysoptera) In West Virginia, Lincoln R. Oliver Jan 2021

Evaluating Avian Occupancy On Sites Treated With Nrcs Conservation Practices Implemented To Benefit Cerulean (Setophaga Cerulea) And Golden-Winged Warblers (Vermivora Chrysoptera) In West Virginia, Lincoln R. Oliver

Graduate Theses, Dissertations, and Problem Reports

The USDA - Natural Resources Conservation Service (NRCS) supports private lands conservation across the United States to benefit imperiled focal wildlife species using conservation practices to restore habitat. Through the Cerulean Warbler (Setophaga cerulea) Forestland Enhancement Project (CWAFEP) and the Working Lands for Wildlife (WLFW) Golden-winged Warbler (Vermivora chrysoptera) initiative, the NRCS provides technical and financial assistance to private landowners to implement conservation practices that follow science-based habitat management guidelines. Few research studies have evaluated focal species-specific occupancy on CWAFEP and/or WLFW sites, and research is required to inform each conservation project’s effectiveness in an adaptive …


Unconventional Gas Pipeline Right-Of-Way Influence On Wildlife, Samuel C. Knopka Jan 2021

Unconventional Gas Pipeline Right-Of-Way Influence On Wildlife, Samuel C. Knopka

Graduate Theses, Dissertations, and Problem Reports

The development of horizontal drilling for natural gas in the Marcellus Shale in 2004 resulted in rapid exploitation of the play in the Appalachian Basin. This “unconventional” gas well drilling accesses resources deeper beneath the surface and allows for multiple wells to be co-located on a single well pad. This results in fewer, but larger, well pads on the landscape than traditional vertical wells. Pipelines are required to transport the volumes of gas produced by unconventional wells to production facilities and market. The effects of gathering pipelines, which transport gas from well pads to larger transport pipelines, are poorly studied …


Evaluating St. Catherines Island's Shoreline, Vegetation Line, And The Locations Of Loggerhead Sea Turtle Nests, Sydney O. Davis Jan 2021

Evaluating St. Catherines Island's Shoreline, Vegetation Line, And The Locations Of Loggerhead Sea Turtle Nests, Sydney O. Davis

Electronic Theses and Dissertations

St. Catherines Island is a highly dynamic barrier island on the Georgia coast that is also federally listed critical nesting habitat for loggerhead sea turtles. Understanding how St. Catherines’ shoreline and vegetation is changing over time is geographically important as a potential template for other barrier islands. Measuring sea turtle nest locations will provide insight into their natural patterns and how they adjust those locations on a changing barrier island. Analyzing Moving Boundaries Using R (AMBUR) is implemented in this research to assess the movement of the vegetation and shorelines from 2005-2017 using the End Point Rate (EPR) and Linear …


Sarracenia Purpurea As A Model System For Aquatic Ecosystem State Changes And Their Impact On Bacterial Communities, Amanda Claire Northrop Jan 2021

Sarracenia Purpurea As A Model System For Aquatic Ecosystem State Changes And Their Impact On Bacterial Communities, Amanda Claire Northrop

Graduate College Dissertations and Theses

Aquatic ecosystems can undergo abrupt and long-lasting transitions from one state to another, often with negative ecological and economic consequences. With anthropogenic enrichment, aquatic ecosystems such as lakes and ponds may shift rapidly from an oligotrophic, clear water state to a eutrophic, turbid state. These shifts, or state changes, generally occur due to a phenomenon called hysteresis in which the relationship between a driving variable and ecosystem variable depend on the current state of the ecosystem. Such dynamics often make recovery difficult or impossible. Though state changes in aquatic ecosystems have been studied extensively since the 1970s, there have been …


Response Of Forest Birds To Spotted Wing Drosophila (Drosophila Suzukii Matsumura), A Novel Invasive Fruit Pest, At Allegheny National Forest, Daniel P. Roche Jan 2021

Response Of Forest Birds To Spotted Wing Drosophila (Drosophila Suzukii Matsumura), A Novel Invasive Fruit Pest, At Allegheny National Forest, Daniel P. Roche

Graduate Theses, Dissertations, and Problem Reports

Non-native invasive insect pests can have dramatic impacts on native ecosystems, feeding on plant foliage, wood, or sap. Little is known, however, about how fruit-targeting NNIIPs may affect native ecosystems. Spotted wing Drosophila (Drosophila suzukii Matsumura, SWD) is a recently introduced invasive vinegar fly that parasitizes the fruits of many plant species in the United States. While its activity in agricultural systems is well-documented, little is known about its activity in forest ecosystems, despite growing evidence of its presence and parasitism of fruits there. Parasitism could reduce fruit attractiveness for vertebrate fruit consumers, including migratory birds. As such, this …


Mycorrhizal Type Dictates Soil Microbial Diversity And Function And The Integrated Root-Microbial Response To Water Stress In Temperate Forests, Nanette C. Raczka Jan 2021

Mycorrhizal Type Dictates Soil Microbial Diversity And Function And The Integrated Root-Microbial Response To Water Stress In Temperate Forests, Nanette C. Raczka

Graduate Theses, Dissertations, and Problem Reports

Our understanding of the mechanisms that control the magnitude of the temperate forest carbon (C) sink and its response to global change remain uncertain. Much of this uncertainty lies in the extent to which differences between tree species in their mycorrhizal symbionts and corresponding nutrient acquisition strategies control the activity of soil microbes that mobilize nutrients and decompose soil organic matter. ECM trees allocate substantial amounts of C to ECM fungi and rhizosphere microbes to mine soil organic matter for nutrients. By contrast, AM trees invest less C belowground and rely on AM fungi to scavenge for nutrients. While these …


Concentration And Composition Of Nanoparticles And Colloidal Particles In A Mine-Waste Contaminated River, Kaitlin Rose Perkins Jan 2021

Concentration And Composition Of Nanoparticles And Colloidal Particles In A Mine-Waste Contaminated River, Kaitlin Rose Perkins

Graduate Student Theses, Dissertations, & Professional Papers

Metals and metalloids (metal(loid)s) in aquatic ecosystems are often described through measures of their concentrations in whole and filtered waters. The filtered fraction is operationally defined as “dissolved,” and assumed to be primarily composed of free metal(loid) ions or of ions bound by low molecular weight organic matter. This definition ignores that the dissolved fraction also likely contains colloidal particles (1 to 1000 nm) that can pass through commonly used filters. This colloidal fraction can also be preferentially removed from the water column by algae and other aquatic organisms compared to free metal(loid) ions and organic bound metal(loid)s. Though they …


Management And Conservation Of Westslope Cutthroat Trout In An Impacted, Connected River System, Troy Weant Smith Jan 2021

Management And Conservation Of Westslope Cutthroat Trout In An Impacted, Connected River System, Troy Weant Smith

Graduate Student Theses, Dissertations, & Professional Papers

Westslope cutthroat trout Oncorhynchus clarkii lewisi (WCT) is a native species of high conservation value that historically exhibited partially migratory behavior throughout its range. Long-term persistence of WCT is threatened by human habitat modification, fragmentation, introduction of non-native species, and hybridization. As a result of these changes, remnant populations in Montana have shifted toward resident populations in headwater systems and away from migratory populations in larger connected river networks. This is compounded by the historic introduction of rainbow trout O. mykiss (RBT) that hybridize with WCT, especially in larger river habitats. Rock Creek in western Montana, USA was historically managed …


Macroinvertebrate Responses To Hydrological Variation In Experimental Wetlands., Sergio A. Sabat-Bonilla Jan 2021

Macroinvertebrate Responses To Hydrological Variation In Experimental Wetlands., Sergio A. Sabat-Bonilla

Electronic Theses and Dissertations

Predicted increases in the frequency of intense storms and periods of severe drought due to climate change represent a threat to wetland macroinvertebrate communities through alterations to the hydrological regime. I used experimental ponds to assess the effects of water permanence (i.e., duration of flooding) on the communities of aquatic macroinvertebrates. I predicted that permanent ponds would harbor higher diversity of longer-lived taxa whereas temporary ones will favor colonization by quick turnover, short-lived taxa and support lower consumer diversity. Results show differences in macroinvertebrate communities between permanent and temporary ponds can be mostly explained by hydrology and the amount of …


Sexual Dimorphism Of Thermal Preference In Florida Scrub Lizards (Sceloporus Woodi) And Predicting Response To Climate Change In Two Rare Habitats, Sidney E. Anderson Jan 2021

Sexual Dimorphism Of Thermal Preference In Florida Scrub Lizards (Sceloporus Woodi) And Predicting Response To Climate Change In Two Rare Habitats, Sidney E. Anderson

Electronic Theses and Dissertations

The Florida Scrub Lizard (Sceloporus woodi) is endemic to Florida, where it inhabits fragments of xeric sandhill uplands including endangered long-leaf pine and sand pine scrub habitats. Lizards depend on a predictable range of temperatures to maximize their growth and productivity, and to do so, they shuttle among various thermal micro-environments. Thus, the spatial distribution of temperatures in the habitat is important. Habitats dominated by either high or low extremes of an organism’s preference are energetically costly and dangerous (less optimal), especially to gravid females. This study examines thermal preference of a near-threatened species that also inhabits increasingly rare habitats. …


An Ecological Comparison Between Resource Subsidies: Pacific Lamprey (Entosphenus Tridentatus) And Pacific Salmon (Oncorhynchus Spp.), Jocelyn Wensloff Jan 2021

An Ecological Comparison Between Resource Subsidies: Pacific Lamprey (Entosphenus Tridentatus) And Pacific Salmon (Oncorhynchus Spp.), Jocelyn Wensloff

All Master's Theses

Historically, oligotrophic Pacific Northwest (PNW) streams received annual returns of spawning anadromous fish that provided resource subsidies in the form of marine-derived nutrients (MDN), thus driving stream food web productivity. To date, many studies in the PNW have focused on Pacific salmon (Oncorhynchus spp.) as a resource subsidy, overlooking other anadromous fish species such as Pacific lamprey (Entosphenus tridentatus). Both Pacific salmon and Pacific lamprey are culturally important to PNW tribes for ceremonial, medicinal, and subsistence purposes, and have been since time immemorial. Unfortunately, both salmon and lamprey populations are in decline. Historically, lamprey have been disregarded …


The Homology Of Sarcopterygian Gills, Kyle Orr Jan 2021

The Homology Of Sarcopterygian Gills, Kyle Orr

Cal Poly Humboldt theses and projects

Vertebrate gills may be either external (protruding from the body surface) or internal (enclosed in a chamber). Among living amphibians, external gills are found in salamander larvae and neotenes, early frog larvae, and caecilian embryos; internal gills are found only in later-stage frog larvae. Evidence for internal gills has also been found in stem tetrapods, and amphibian-like external gills have been found in some fossil temnospondyls and anthracosaurs. Gill homology among these groups and life stages has long been questioned. To address this, scanning electron microscopy, vascular casting, and paraffin sectioning were utilized to study the morphology of gills and …


Use Of Redwood Basal Hollows By Bats: A Focus On The Townsend's Big-Eared Bat On The North Coast Of California, Amon Jotesh Armstrong Jan 2021

Use Of Redwood Basal Hollows By Bats: A Focus On The Townsend's Big-Eared Bat On The North Coast Of California, Amon Jotesh Armstrong

Cal Poly Humboldt theses and projects

Loss of roosting resources, either through disturbance or removal, negatively affects bats. For sensitive species, such as the Townsend’s big-eared bat (Corynorhinus townsendii), determining roost requirements is a critical component in conserving their habitat. Such cavity roosting bats on the North Coast of California may use hollows in large redwood trees. In this study, I examined the factors determining the use of basal tree hollows by different bat species at eight redwood forest sites in Del Norte, Humboldt, and Mendocino Counties, California. Bat guano was collected from 179 basal hollow roosts from 2017 to 2018, and guano mass …


Comparison Of Standard And Environmental Dna Methods For Estimating Chinook Salmon Smolt Abundance In The Klamath River, California, Doyle Joseph Coyne Jan 2021

Comparison Of Standard And Environmental Dna Methods For Estimating Chinook Salmon Smolt Abundance In The Klamath River, California, Doyle Joseph Coyne

Cal Poly Humboldt theses and projects

Evaluating abundance of juvenile salmonids is critical to conservation and management. Current abundance estimation involves use of rotary screw traps and mark-recapture studies. Use of environmental DNA (eDNA) in water samples offers a noninvasive and less expensive approach that may potentially improve or eventually replace traditional monitoring. Here I evaluate the utility of eDNA to predict weekly abundance estimates of outmigrating Chinook salmon (Oncorhynchus tshawytscha) smolts in the Klamath River, California. A total of 15 water samples were collected per week over the 17-week smolt outmigration in both 2019 and 2020. Chinook salmon eDNA concentration in each water …


Seed Bank Composition Within Two Sagebrush Communities: A Comparison Of Drought, Microsite, And Aboveground Community Effects, Allison Marie Nunes Jan 2021

Seed Bank Composition Within Two Sagebrush Communities: A Comparison Of Drought, Microsite, And Aboveground Community Effects, Allison Marie Nunes

Cal Poly Humboldt theses and projects

Soil seed banks are critical biodiversity repositories for many dryland plant communities. Understanding how environmental factors alter seed bank composition can provide valuable information on ecological processes within a community and be useful for creating land management strategies. Using the seedling emergence method, I characterized the seed bank of two adjacent dryland plant communities that vary in dominant sagebrush species, structure, and function. Specifically, within an Artemisia arbuscula dominated community and Artemisia cana dominated community, I assessed the influence of three environmental factors on each seed bank: experimentally imposed drought, shrub microsites (compared to interspaces), and aboveground vegetation. Within the …


Do Beaver Dam Analogues Act As Passage Barriers To Juvenile Coho Salmon And Juvenile Steelhead Trout?, Christopher G. O'Keefe Jan 2021

Do Beaver Dam Analogues Act As Passage Barriers To Juvenile Coho Salmon And Juvenile Steelhead Trout?, Christopher G. O'Keefe

Cal Poly Humboldt theses and projects

In the Pacific Northwest, the human-caused reduction of quality and quantity of freshwater rearing habitat is a limiting factor for Pacific Salmon populations. Beaver dam analogues (BDAs) increase suitable rearing habitat for juvenile salmonids and promote the restoration of critical stream processes. Installing BDAs is an increasingly popular alternative to more intensive restoration techniques, due to the relatively low cost and effort required to install BDA structures. However, widespread installation of BDAs has been slowed by regulatory agencies’ concerns that BDAs may impede fish passage. Few studies have empirically assessed the extent to which BDAs impede fish passage, and no …


Evaluating Immaturity Risk In Young Stands Of The Serotinous Knobcone Pine (Pinus Attenuata), Katherine Marlin Jan 2021

Evaluating Immaturity Risk In Young Stands Of The Serotinous Knobcone Pine (Pinus Attenuata), Katherine Marlin

Cal Poly Humboldt theses and projects

As wildfire becomes increasingly frequent, many plant populations risk local extirpation if fire recurs too soon, a problem dubbed “immaturity risk”. We studied the regeneration of a serotinous conifer species, knobcone pine (Pinus attenuata), as a function of the time between high-severity fires (6-79 years). We evaluated age, cone production, and regeneration at two burned sites in northern California, the Ranch Fire (2018) in Mendocino National Forest, and the Carr Fire (2018) in Whiskeytown National Recreation Area. We found an average of 30.5 filled seeds in closed, brown cones (42% viability of filled seeds). The bulk of the …


Social Comparison Tendencies And The Reward Value Of Same-Sex Beauty Among Heterosexual Women, Melissa M. Martin Ms. Jan 2021

Social Comparison Tendencies And The Reward Value Of Same-Sex Beauty Among Heterosexual Women, Melissa M. Martin Ms.

Cal Poly Humboldt theses and projects

Previous studies have suggested that heterosexual women, but not heterosexual men, find same sex beauty rewarding. This finding has been attributed to a “greater bisexual interest among heterosexual women”, but no other explanations have been offered or tested. The current study aimed to explore social comparison tendencies as a potential alternate explanation to this previously observed finding. Twenty-three heterosexual women completed a series of questionnaires designed to assess their social comparison tendencies (the social comparison orientation scale, the physical appearance comparison scale, and the intrasexual competition scale). They also completed a “pay-per-view” keypress task to measure the reward value of …


Building Habitat Suitability Models To Examine Distribution Shifts For The Black-Headed Grosbeak, Hairy Woodpecker, And Yellow-Rumped Warbler Due To Drought, Fire, And Bark Beetle Infestation In The Pacific Northwest, Holli Nicole Pruhsmeier Jan 2021

Building Habitat Suitability Models To Examine Distribution Shifts For The Black-Headed Grosbeak, Hairy Woodpecker, And Yellow-Rumped Warbler Due To Drought, Fire, And Bark Beetle Infestation In The Pacific Northwest, Holli Nicole Pruhsmeier

Cal Poly Humboldt theses and projects

Spatial models that describe species distributions are valuable in determining how environmental impacts, such as drought, fire, and bark beetle infestations, have shifted these distributions and guide management decisions. In this thesis, I begin by comparing the utility of two datasets by building habitat suitability models for Black-headed Grosbeak, Hairy Woodpecker, and Yellow-rumped Warbler. By combining the datasets, I created response curves that explain habitat associations I expected from each species. I expanded upon the methods section to compare pre- and post-drought data from the 2011 California multi-year drought and evaluate how the three avian species have shifted their habitat …