Physical Sciences and Mathematics Commons^™

On The Acceptance Of Urban Beavers In Martinez, California, Zane A. Eddy

Cal Poly Humboldt theses and projects

As ecosystem engineers, beavers construct complex riparian and wetland habitats that benefit many other species, including endangered salmonids. Through their landscape alterations, beavers also promote increased groundwater recharge and provide refugia during wildfires and high flow events by impounding water and allowing it to spread across the landscape. Prior to the North American colonial fur trapping campaigns, there were between 60 and 400 million beavers in North America. By the beginning of the 20th century, beavers were extirpated from many parts of the continent, however through human efforts, their population has since rebounded to between 10 and 15 million. The …

Comparison Of Low-Cost Commercial Unpiloted Digital Aerial Photogrammetry To Airborne Laser Scanning Across Multiple Forest Types In California, James Edward Lamping

Cal Poly Humboldt theses and projects

Science-based forest management requires quantitative information about forest attributes traditionally collected via sampled field plots in a forest inventory program. Remote sensing tools, such as active three-dimensional (3D) Light Detection and Ranging (lidar), are increasingly utilized to supplement and even replace field-based forest inventories. However, lidar remains cost prohibitive for smaller areas and repeat measurement, often limiting its use to single acquisitions of large contiguous areas. Recent advancements in unpiloted aerial systems (UAS), digital aerial photogrammetry (DAP) and high precision global positioning systems (HPGPS) have the potential to provide low-cost time and place flexible 3D data to support forest inventory …

Using Uav And Traditional Remote Sensing Data To Detect Vegetation Vigor And Monitor Stream Morphology In A Desert Riparian Ecosystem, Jordan Bradley Adair

Cal Poly Humboldt theses and projects

Mono Lake is a terminal lake in the Eastern Sierra Nevada Mountains. The streams that feed Mono Lake support a unique desert riparian ecosystem. Rush Creek was the stream of interest for this study. The objective of this research is to determine if remotely sensed imagery can be used to determine vegetation vigor and measure stream morphologic features in a desert riparian area. The goals were to evaluate different sources of remotely sensed imagery to make these determinations. The Normalized Difference Vegetation Index (NDVI) was used to monitor vegetation vigor along Rush Creek. Google Earth imagery and UAV derived imagery …

Response Of Invertebrate Drift To Dam-Release Restoration Pulse Flows From Lewiston Dam On The Trinity River, Ca, Jasmine S. Williamshen

Cal Poly Humboldt theses and projects

The widespread construction of dams to regulate rivers has dramatically altered aquatic ecosystems, but these impoundments also provide a unique opportunity to support freshwater conservation goals by implementing functional flow regimes designed to mitigate dam-related impacts on fisheries. Drifting invertebrates are an important food source for stream-dwelling juvenile salmonids such that drift feeding can be an energetically profitable foraging strategy, yet the effect of streamflow alterations on invertebrate drift dynamics is largely undetermined. Drift net samples were collected on four days before and four days during the ascending limb (14-42 m³/s) of restoration pulse flows in April 2020 …

Satellite-Based Phenology Analysis In Evaluating The Response Of Puerto Rico And The United States Virgin Islands' Tropical Forests To The 2017 Hurricanes, Melissa Collin

Cal Poly Humboldt theses and projects

The functionality of tropical forest ecosystems and their productivity is highly related to the timing of phenological events. Understanding forest responses to major climate events is crucial for predicting the potential impacts of climate change. This research utilized Landsat satellite data and ground-based Forest Inventory and Analysis (FIA) plot data to investigate the dynamics of Puerto Rico and the U.S. Virgin Islands’ (PRVI) tropical forests after two major hurricanes in 2017. Analyzing these two datasets allowed for validation of the remote sensing methodology with field data and for the investigation of whether this is an appropriate approach for estimating forest …

Assessing California Commercial Fishing Community Well-Being In The Context Of Marine Protected Area (Mpa) Formation, Samantha Cook

Cal Poly Humboldt theses and projects

Marine protected areas (MPAs)—defined geographic areas where fishing and harvesting activity is limited or restricted—have emerged as a popular marine biodiversity and climate resilience strategy worldwide. MPA monitoring efforts often follow MPA designation to help inform the adaptive management of MPAs and MPA networks. In 2012, California completed the largest statewide system of MPAs to date, consisting of 124 MPAs covering 16% of state waters. Following MPA implementation, the state initiated a long-term monitoring program (2019-2022) to help inform the 10-year MPA management review. This two-chapter thesis presents findings from a state-funded project to conduct long-term socioeconomic monitoring for human …

Resolving Variability In Size Structure In An Individual-Based Model For The North Pacific Krill, Euphausia Pacifica, Roxanne Robertson

Cal Poly Humboldt theses and projects

Individual-based models (IBMs) have emerged as a powerful tool for ecological research and are particularly well suited to studies of plankton ecology. In this thesis, I develop an IBM for the North Pacific krill, Euphausia pacifica, with the goal of replicating observed variability in size-structure in the northern California Current Ecosystem. Krill, and E. pacifica in particular, are central to the structure and function of the California Current Ecosystem. Their response to environmental forcing translates climate variability to higher trophic levels and underpins broader ecosystem responses. Recent observations indicate environmental and climate-related shifts in E. pacifica size distributions, which …

An Analysis Of The Global Warming Impact Of Humboldt State University's Refrigerant Inventory, Alex Eckert-Ross

Cal Poly Humboldt theses and projects

With global warming potentials (GWP) in the thousands to tens of thousands of metric tons of carbon dioxide equivalent (MTCO₂e) and the possibility for substantial emissions associated with leaks of refrigerants used in heating, ventilation, air conditioning, and refrigeration (HVACR) equipment, it is important for Humboldt State University (HSU) to document and report greenhouse gas emissions (GHG) associated with refrigerant leaks.

This study has collected data on HSU’s HVACR inventory, emphasizing the refrigerant types used, the charges of the equipment (i.e., the amounts of refrigerant in the systems), and the types of equipment. The data were aggregated into …

Merging Art And Science: Lessons Learned From An 'Otterly' Different Case Study, Jess Barger

Cal Poly Humboldt theses and projects

Environmental art projects use artistic interpretation to tell stories about the natural world, often with the hope that they will inspire awareness or behavioral change. In 2019, an art project to raise awareness about North American river otters (Lontra canadensis) was launched in Northern California, using over 100 river otter sculptures painted and decorated by local artists. Through a mixed-methods approach, I quantified the initial outcomes of the project, North Coast Otters, as well as the response to the project by the public on social media as a case study in environmental art and outreach. Participating artists’ interviews and …

Structural And Thermochronologic Evidence Of Paleogene-Neogene Faulting And Exhumation Of The Klamath Mountain Province, Taylor C. Team

Cal Poly Humboldt theses and projects

The Klamath Mountains Province (KMP), located at the southern end of the forearc of the Cascadia Subduction Zone, displays a distinct topographic and geologic signature. Compared to the forearc in the north, the KMP comprises Paleozoic-Mesozoic basement rocks with relatively high modern elevation and relief. This study investigates the pattern of rock cooling in the KMP by using thermochronology on plutons exhumed by faults and plutons outside of mapped faults. In this study, I target three regions in the KMP: the Ashland pluton offset by the Siskiyou Summit fault in the northeast KMP, the Grayback pluton in the northwest KMP, …

A Comparison Of The Removal Of Estrogen Between Different Wastewater Treatment Processes, Danielle J. Jones

Cal Poly Humboldt theses and projects

Pharmaceuticals are found in water systems and are classified as contaminants due to their adverse effects on numerous types of aquatic organisms. Estradiol, a natural occurring estrogen and ethinylestradiol, a common synthetic estrogen found in birth control, are a class of pharmaceuticals called endocrine-disruptive contaminants (EDC). These contaminants have been shown to cause developmental delays in fish as well as feminizing male fish in concentrations as low as 1 ng/L for both estradiol and ethinylestradiol, and bioaccumulating in mollusks and oysters. There are many natural and human-assisted methods for removing pharmaceuticals in water, and they are dependent on both the …

Can A Remote Sensing Approach With Hyperspectral Data Provide Early Detection And Mapping Of Spatial Patterns Of Black Bear Bark Stripping In Coast Redwoods?, Shayne R. Magstadt

Cal Poly Humboldt theses and projects

The prevalence of black bear (Ursus americanus) bark stripping in commercial redwood (Sequoia sempervirens) timer stands has been increasing in recent years. This stripping is a threat to commercial timber production because of the deleterious effects on redwood tree fitness. This study sought to unveil a remote sensing method to detect these damaged trees early and map their spatial patterns. By developing a timely monitoring method, forest timber companies can manipulate their timber harvesting routines to adapt to the consequences of the problem. We explored the utility of high spatial resolution UAV-collected hyperspectral imagery as a …

Effects Of Large Wood Restoration On Coho Salmon In A Northern California Watershed: A Before-After-Control-Impact Experiment, Natalie B. Okun

Cal Poly Humboldt theses and projects

Substantial time, money, and effort are invested in river and stream restoration projects to aid in the recovery of imperiled salmonid populations, but there is little evidence that these efforts have had lasting positive impacts on juvenile fish growth and survival. To assess the effectiveness of large woody debris (LWD) restoration, which is one of the most common restoration practices, I evaluated the growth and survival response of endangered Central California Coast coho salmon (Oncorhynchus kisutch) in a paired watershed before-after impact-control (BACI) study. To determine if LWD supplementation influenced coho salmon growth and survival, two neighboring, similar …

Response Of Coastal Ichthyoplankton Assemblages Off Northern California To Seasonal Oceanographic And Climate Variability, Blair M. Winnacott

Cal Poly Humboldt theses and projects

This study analyzed samples collected along the Trinidad Head Line (41°N) to characterize variability in the ichthyoplankton assemblage in coastal waters off northern California from late 2007 through 2019, a period during which a major marine heatwave (MHW; late 2014-16) strongly perturbed the ecosystem. I augmented visual identification with genetic techniques to resolve the species composition of visually cryptic larval rockfishes (Sebastes spp.). While taxonomic composition off northern California was largely similar to studies off Oregon and Washington, and cross-shelf structure and seasonal patterns in species’ abundance were generally consistent with the distribution and phenology of parental stocks, interannual …

Evidence For Middle Miocene Elevated Topography Isolating The Southern Klamath Mountains Province: A U-Pb & Lu-Hf Detrital Zircon Study Of The Weaverville Formation, Dana J. Christensen

Cal Poly Humboldt theses and projects

The Klamath Mountains Province (KMP) records a robust history of active North American margin tectonics and crustal growth through the subduction-accretion of oceanic and island-arc terranes spanning Devonian through Cretaceous time. However, preservation of Cenozoic rocks is minimal, rendering the geologic record, topography, and tectonics during this timeframe difficult to reconstruct. The only Miocene terrestrial sedimentary unit that exists in the KMP is the fluvially deposited Tertiary Weaverville Formation (Tw) that is preserved in five fault-bounded basins in the southern part of the province. This study presents new uranium-lead (U-Pb) age data and epsilon hafnium (εHf) isotopic ratios from detrital …

Spatiotemporal Patterns In Water Yield From The Humid Puna: A Case Study In The Agrarian District Of Zurite, Perú, Wyeth Wunderlich

Cal Poly Humboldt theses and projects

The humid puna is a seasonally dry alpine grass- and shrub-land biome that exists at the altitudinal limits of plant survival, hosts peat-forming wetlands known as bofedales, and yields water to streams used by small and large communities throughout the central and southern Peruvian Andes. Despite the importance of the humid puna in supplying water resources, particularly to perennial streams, few studies have quantified water yield and no studies have explored relationships between the structure of puna landscapes and spatial patterns in water yield. Zurite (population: 3,640, elevation: 3,011 m.a.s.l., annual precipitation: 855 mm) is an agrarian district in …

A Look At Land Cover Classification Methods In Northern California With The Use Of High Spatial Resolution Geospatial Data, Lucila Corro

Cal Poly Humboldt theses and projects

Land use and land cover (LULC) mapping plays a vital role in understanding the state of the world, showing us a visual representation of the natural and anthropogenic features covering our planet. Northern California in the United States is home to many critical habitats that provide for a variety of endemic and some threatened and engendered species, making it an area of particular concern to better understand and monitor. There is a greater need to identify specific methods for vegetation modeling in Northern California due to its unique species; to do this we examined two case studies with the following …