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Habitat Use And Prey Selection By Mountain Lions In An Altered Sagebrush Steppe Environment, Jonathan Ewanyk

Cal Poly Humboldt theses and projects

Throughout the American West there is an increasing trend of encroachment of woody vegetation on previously open sagebrush steppe habitat. The Modoc Plateau in northeastern California has not been excluded from this encroachment trend and has seen an increase in western juniper (Juniperus occidentalis) densities, likely as a result of long-term fire suppression. Mountain lions (Puma concolor) have not previously been studied on the Modoc Plateau, and there is potential for an increase in cover due to juniper encroachment to benefit the hunting behavior of lions. To better understand if the presence of cover is being …

Coho Salmon (Oncorhynchus Kisutch) Dispersal And Life History Variations Among Humboldt Bay Watersheds, Madison J. Halloran

Cal Poly Humboldt theses and projects

The decline of Coho Salmon (Oncorhynchus kisutch) in California is the result of various anthropogenic effects across the landscape, affecting all stages of their anadromous life history. Monitoring a subset of the remaining populations is essential to evaluate the success of management actions and develop new restoration projects. Defining the appropriate spatial scale for this monitoring and restoration depends on the frequency and extent of dispersal of individuals across watershed boundaries. Coho Salmon life-cycle monitoring projects in California estimate the abundance of juveniles and adults over time in selected focal watersheds. If individuals frequently enter or leave the …

The Effects Of Feral Cat Removal On Rat Abundance In An Insular, Tropical Ecosystem, Douglas A. Page

Cal Poly Humboldt theses and projects

The colonization by rats (Rattus spp.) and cats (Felis catus) on islands are known to contribute to the decline of native birds. On the island of Rota, Commonwealth of the Northern Mariana Islands, cats are being lethally removed to conserve two endangered bird species. Although cats are controlled to reduce impacts on birds, they can also prey heavily on sympatric rats. Of euthanized feral cats on Rota, 60% had ≥1 rat in the stomach. Predation by cats could be a mechanism of top-down control of rats. Removing feral cats may reduce the magnitude of that control, leading …

Characterization Of Greenhouse Gas Emissions From Storage Of Woody Biomass: An Incubation Study, Carisse Geronimo

Cal Poly Humboldt theses and projects

Biomass energy plays a small but significant role in the current renewable energy portfolio and is a promising alternative pathway for woody residues that would otherwise be considered waste. These woody residues are often stored in large piles prior to combustion, and greenhouse gas emissions from this storage phase of the bioenergy supply chain are uncertain and understudied. This incubation study investigates the effects of three environmental factors on emissions from decomposition of woody biomass stored in chip piles. Incubation experiments were conducted, subjecting chambers of Sequoia sempervirens woodchips to different levels of temperature, oxygen concentration, and moisture content, and …

Shifting Sands: Social Cues Influence The Long-Term Dynamics Of Snowy Plover Distribution, Jeremy John Pohlman Mr

Cal Poly Humboldt theses and projects

Understanding the social and physical factors that influence the temporal and spatial distribution of a species is imperative for successful management. The Western Snowy Plover (Charadrius nivosus nivosus) selects for wide-open stretches of beach; yet within large expanses of ideal habitat, plover populations tend to be aggregated. Recent evidence suggests plovers may prioritize social information over ideal physical factors alone when selecting breeding locations. I analyzed data collected on an individually marked population of Snowy Plovers in Humboldt County, California from 2001 to 2018 to evaluate the influence of physical (beach width) and social (presence of conspecifics) landscape …

Decay Of Woody Residues As The Counterfactual Treatment To Mobilization For Bioelectricity Generation, Max A. Blasdel

Cal Poly Humboldt theses and projects

Decay of woody debris is a major carbon flux for forests. Decay processes are not well documented in forest modeling frameworks but play an important role in forest carbon cycling and life cycle assessments of forest-derived products. The main drivers of decay are species, vertical location, and climate. A database of literature values for decay by tree species was created to parameterize a larger model of California forestland carbon cycling. A novel methodology was applied to vary these decay values for each species spatially based on climatic drivers of decay. This resulted in decay values for each species and size …

Distribution And Evolution Of Fukushima Dai-Ichi Derived 137cs, 90sr, And 129i In Surface Seawater Off The Coast Of Japan, Jennifer A. Kenyon, Ken O. Buesseler, Núria Casacuberta, Maxi Castrillejo, Shigeyoshi Otosaka, Pere Masqué, Jessica A. Drysdale, Steven M. Pike, Virginie Sanial

Research outputs 2014 to 2021

© 2020 American Chemical Society. The Fukushima Dai-ichi Nuclear Power Plants (FDNPPs) accident in 2011 led to an unprecedented release of radionuclides into the environment. Particularly important are 90Sr and 137Cs due to their known health detriments and long half-lives (T1/2 ≈ 30 y) relative to ecological systems. These radionuclides can be combined with the longer-lived 129I (T1/2 = 15.7 My) to trace hydrologic, atmospheric, oceanic, and geochemical processes. This study seeks to evaluate 137Cs, 90Sr, and 129I concentrations in seawater off the coast of Japan, reconcile the sources of contaminated waters, and assess the application of 137Cs/90Sr, 129I/137Cs, and …

In Vitro Antifungal Activity Of Desmodium Intortum And D. Uncinatum Root Extracts Against Growth Of Toxigenic Fusarium Verticillioides And Aspergillus Flavus, Nancy Karimi Njeru, Charles Aura Odhiambo Midega, James Wanjohi Muthomi, John Maina Wagacha, Zeyaur Rahman Khan

All Peer-Reviewed Publications

Maize grown under push-pull cropping system has been reported to contain lower concentrations of fumonisin and aflatoxin than maize monocrop. This study determined the inhibitory effect of desmodium root extracts on spore germination and radial growth of toxigenic Aspergillus flavus and Fusarium verticillioides. Aspergillus flavus and F. verticillioides were isolated from maize and soil and tested for ability to produce aflatoxin and fumonisin by inoculation on mycotoxin-free maize. Aflatoxin and fuminisin were detected and quantified by direct competitive ELISA. Desmodium roots were dried, ground to fine powder and extracted with methanol and dichloromethane and evaluated for anti-fungal activity by inhibition …

Restricting Pesticides On A Traditional Crop: The Example Of Khat (Catha Edulis) And The Njuri Ncheke Of Meru, Kenya, James S. Krueger, Daniel M. Mutyambai

All Peer-Reviewed Publications

Rampant increase and diversification of synthetic pesticides poses health, environmental, and livelihood risks especially to smallholder farmers who dominate agriculture in sub-Saharan Africa. Legal mechanisms for regulating pesticides, although important, have not fully addressed the dangers of ecological services disruptions due to accumulation of different pesticides over time. Legal mechanisms also are not well suited to developing countries because of weak monitoring and enforcement capacity. Understanding the role of other accountability mechanisms in farming, driven by norm leaders in the community, is thus of paramount importance. We investigated the effectiveness of a traditional accountability mechanism, i.e., local councils of elders …

A Pedagogy Of Hope: Levers Of Change In Transformative Place-Based Learning Systems, Michelle G. Heaton

Antioch University Dissertations & Theses

In response to mounting wicked environmental problems and an outdated U.S. educational system, this dissertation investigates transformative place-based education as an adaptive boundary system that connects individual learning to positive social-ecological change. The research approaches learning through a systems lens through a novel framework of Social-ecological Systems, Place-based Education, and Transformative Learning Theories. A three-part mixed methods approach, including content analysis of the literature, phenomenological interviews with experts in place-based education, and fuzzy-logic cognitive mapping with educators at three schools practicing the principles of place-based education, is used to examine transformative place-based education from the perspectives of current U.S. place-based …

Developing An Odonate-Based Index For Monitoring Freshwater Ecosystems In Rwanda: Towards Linking Policy To Practice Through Integrated And Adaptive Management, Erasme Uyizeye

Antioch University Dissertations & Theses

Worldwide, the decline of biodiversity in freshwater ecosystems is occurring at an alarming rate, due to anthropogenic threats, which directly impact humans in a variety of ways. Freshwater ecosystems occupy an integral part of political, socio-economic and ecological spheres. Integrated Watershed Management (IWM) and Adaptive Management (AM) conceptual frameworks provide an underpinning holistic platform from which to evaluate the performance of policies and actions on the ground in relation to freshwater ecosystem management. I investigate the extent to which environmental policies and practices embrace IWM and AM frameworks in Rwanda. Furthermore, this dissertation develops an odonate-based ecological monitoring tool, referred …

The Potential Role Of Payment For Ecosystem Services In Protected Area Management In Rwanda: A Case Study From Gishwati-Mukura National Park, Yves Gakunde

Antioch University Dissertations & Theses

The demand for ecosystem services (ES) by communities around the world especially from developing countries is increasing, and creates conflict between protected ecosystem management and community socioeconomic wellbeing needs, particularly around protected areas. Taking into consideration globalization, capitalism, weak policies, and population growth as some of the majors driving factors to land change, increased demand for ES comes in part from societies’ changing economic demands and opportunities, such as food and commercial crop production, timber extraction, urbanization, and infrastructural development. Many biodiversity conservation approaches and initiatives have been used to protect and maintain healthy ecosystems. While the fence and fine …

Emotional Response To Climate Change Learning: An Existential Inquiry, Jennifer Hutchinson

Antioch University Dissertations & Theses

This qualitative study aims to explore and explain the existential underpinnings of learning about climate change and potential emotional responses to climate change learning. Undergraduate students in environmental sciences and studies classes at the University of Washingrounded theory on in Seattle, WA participated in semi-structured interviews. Participants were asked about their experiences learning about climate change and how they responded emotionally to the learning. This dissertation examines the responses from those interviews and builds a theory out of the data analyzed. Constructivist Grounded theory as outlined by Kathy Charmaz (2014) was used to analyze the interviews. Codes were created and …

Integrated Techno-Economic And Life Cycle Analyses Of Biomass Utilization For Value-Added Bioproducts In The Northeastern United States, Yuxi Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

A multi-stage spatial analysis was first conducted to select locations for lignocellulosic biomass-based bioproduct facility, using Geographical Information System (GIS) spatial analysis, multi-criteria analysis ranking algorithm, and social-economic assessment. A case study was developed to determine locations for lignocellulosic biorefineries using feedstocks including forest residue biomass and three energy crops for 13 states in the northeastern United States. In the entire study area, 11.1% of the counties are high-suitable, 48.8% are medium-suitable for biorefinery siting locations. A non-parametric analysis of cross-group surveys showed that preferences on biorefinery siting are homogeneous for experts in academia and industry groups, but people in …

Habitat Stability In Appalachian Headwater Systems And Potential Impacts On Brook Trout Populations, Zac F.W Zacavish

Graduate Theses, Dissertations, and Problem Reports (ETD)

The impact climate change will have on the habitat for Brook Trout (Salvelinus fontinalis) could directly impact key demographic characteristics. Traditionally, broad-scale studies of climate change effects on the family Salmonidae focus on the thermal shifts predicted over the next century. While some studies shed light onto other variables such as biotic interactions, flow regime, and disturbance, the significance of the climate-trout interaction is not always observed. With the high degree of influence climate cycles can have on habitat and channel morphology, this study aimed to highlight temporal habitat shifts to begin addressing climate-habitat interaction. By studying habitat distribution …

Relating Recharge Mechanisms To Chemical Changes In An Updip Appalachian Coal Mine Discharge: A Case Study From Lambert Run, West Virginia, Matthew Lewis Bell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Impaired drainage from active and abandoned mines degrades the water quality of receiving streams and aquifers. Coal mine drainage (CMD) has been studied for decades in Appalachia, but unknowns and uncertainties are still present, including the influence of mine hydrogeology on the outflow chemistry of above-drainage mines. To evaluate the influence of recharge type on above-drainage mine chemistry, samples were collected every two weeks at a CMD outflow treatment system in Harrison County, West Virginia.

Samples were collected to measure geochemical changes taking place in the mine workings and along the flowpath of the passive treatment system. Samples were divided …

Microbial Responses To Unconventional Oil And Gas Development May Alter Ecosystem Function In Headwater Streams, Rachel Michaels

Graduate Theses, Dissertations, and Problem Reports (ETD)

The demand for natural gas, and the need for efficient extraction, has led to the development of unconventional oil and natural gas (UOG) techniques. Due to the novelty of UOG, the potential impacts to freshwater ecosystems are not fully understood. We used a dual pronged approach to study the effects of UOG development on microbial biodiversity and function via a laboratory microcosm experiment and a survey study of streams with and without UOG development within their watersheds. The laboratory microcosm study simulated stream contamination with produced water, a byproduct of UOG operation, using sediment collected from one high water-quality stream …

Spawning Characteristics Of Yellow Perch During Periods Of Water Level Fluctuations In A Hydropower Reservoir, Kyle J. Matt

Graduate Theses, Dissertations, and Problem Reports (ETD)

Water level fluctuations alter reservoir ecosystems causing direct and indirect effects on fish populations. The dewatering of eggs, a direct impact of lake level drawdowns, can affect reproductive success of species that spawn in littoral zones, such as Yellow Perch. I examined relationships between water level fluctuations and spawning characteristics of Yellow Perch in a Central Appalachian hydropower reservoir, where water levels were permitted to be drawn down to 4 m and 2.1 m below the full pool elevation in March and April, respectively. Daily presences of egg masses were recorded on artificial spawning structures at two sites for the …

Leaf Angle And Leaf Stomata Responses To Experimental Drought In Quercus Velutina And Acer Saccharum, Brittany Nichole Casey

Graduate Theses, Dissertations, and Problem Reports (ETD)

The possibility of increased severity and frequency of drought conditions, as a result of global climate variability, greatly complicates our ability to forecast future forest functions such as productivity and carbon sequestration. Assessing how tree species vary in their response to drought can aid in predicting the impact on forest ecosystems as a whole. Throughfall exclusion (TfE) experiments are potentially useful tools to simulate realistic drought conditions within intact forest ecosystems. We employed a TfE experiment during the 2018 growing season within the WV Land Trust’s Elizabeth’s Woods Nature Preserve, near Morgantown, WV, to assess the leaf angle and leaf …

Dendroclimatic Analysis And Site Index Modeling Of Central Appalachian Red Spruce, Eric L. Yetter

Graduate Theses, Dissertations, and Problem Reports (ETD)

Red spruce (Picea rubens) was historically an important and dominant timber species in the central Appalachian mountain range. The tree species is now found in a small fraction of its original home range. Threatened and endangered organisms such as the Cheat Mountain Salamander (Plethodon nettingi) rely on red spruce associated forests for survival. Recent concerns including air pollution and climate change may threaten the health of remaining red spruce populations.

I used dendrochronology data to conduct historic dendroclimatic analyses and construct future growth projections for red spruce throughout the central Appalachians. My research involves the use of tree core data …

A Geostatistical Study Of Socioeconomic Status (Ses), Rurality, Seasonality And Index Test Results As Drivers Of Free Private Groundwater Testing In Southern Ontario, 2012–2016, Shahryar Qayyum, Paul Hynds, Harriet Richardson, Kevin Mcdermott, Anna Majury

Articles

Approximately 12% of the Canadian population uses private wells for daily water consumption; however, well water testing rates are on the decline, resulting in an increased risk of waterborne acute gastrointestinal illness. To date, limited research has explored the determinants influencing well testing practices. Accordingly, the current study sought to investigate the drivers of “one-off” and repeat well water testing in southern Ontario during the 5-year period 2012–2016, using the worlds largest private groundwater testing data-frame. Data from >400,000 wells were geospatially integrated with all tests conducted by the provincial laboratory in southern Ontario. The Ontario Marginalization Index (ON-Marg) was …

Reconciling Carbon Flux Discrepancies In A Desert Environment: Characterizing Influences Of Soil Processes Using Automated Co2 Flux Chambers, Alejandro Lara

Open Access Theses & Dissertations

Dryland ecosystems play a fundamental role in controlling the balance of carbon on a global scale. These ecosystems dominate the inter-annual variability of carbon uptake by terrestrial ecosystems, and this is driven by temperature and precipitation patterns. Despite this global importance, there are some important discrepancies that have been reported between CO2 fluxes measured with differing techniques, particularly between eddy covariance tower measurements of net ecosystem exchange (NEE) of carbon (C) versus on-the-ground methods such as chambers and biomass surveys. The discrepancy is a consequence of instrumentation and measurement technique differences; yet, its biological origins remain unknown. The goal of …

Antioxidant Intervention In Radical-Induced Protein Damage, Emmanuel Zubia

Open Access Theses & Dissertations

Many environmental toxicants are known to increase free-radical production, which can create cellular havoc and lead to a myriad of ailments. Antioxidants can be used to ameliorate the prevalence of free radicals, potentially serving as prophylactics against radical-induced disorders. Many exogenous antioxidants are phytochemicals in origin, such as ascorbic acid, gallic acid, and ellagic acid. Some of these antioxidants can be found in traditional medicine, like tanshinone and brazilin, which have been studied and are known to have low cytotoxicity. Here we test the radical rescue capacity of a selected group of phytochemical antioxidants on protein rescue models. Specifically, our …

Partitioning Variation In Vegetation And Landscape Functionality In Arid Land Piosphere, Eahsan Shahriary

Open Access Theses & Dissertations

A piosphere is an interaction between vegetation community, watering point, and grazing livestock/wildlife. In this Dissertation, I begin by reviewing the concept of the piosphere, and the progress, knowledge gaps and common statistical approaches and errors in piosphere research. Landscape functionality, plant community distribution and their influencing factors on a piosphere in Iran are then investigated.

A total 862 piosphere publications of multiple types from 68 countries and 10 different languages during the period of 1915 â?? 2018 were reviewed. Australia was the most productive country followed by South Africa, the USA, Botswana and Argentina. Ivan Thrash is the most …

Using Environmental Identity To Promote Environmental Concern And Willingness To Participate In Endangered Species Conservation, Christina M. Wesolek

Antioch University Dissertations & Theses

Environmental identity (EID), a concept from the social sciences specifically conservation psychology, refers to how we orient ourselves to the natural world, and thereby take action based on our personality, values, and sense of self. The realization that conservation is a human endeavor has prompted the inclusion of the social sciences in conservation research. Research on environmental identity has been conducted in such places as zoos, higher education institutions, and with farmers, and has demonstrated that EID is a good predictor of environmental concern and proenvironmental behaviors. There is a gap in the literature regarding whether environmental identity can be …

Life Cycle Studies To Evaluate The Physiological And Biochemical Effects Of Copper Oxide And Surface-Coated Titanium Dioxide Nanoparticles On Green Onion (Allium Fistulosum) And Carrot (Daucus Carota L.) Plants: Insights Utilizing Two-Photon Microscopy And Spectroscopy, Yi Wang

Open Access Theses & Dissertations

With the recent increase of nanomaterial production, nano copper oxide (nCuO) and surface-modified titanium dioxide nanoparticles (nTiO2) are among the most widely applied nanoparticles in industry and daily lives. Their use has resulted in accumulation in soils as a consequence of their direct or indirect release. Hence, these NPs may raise a potential risk to crops cultivated in soils. Moreover, the physiological effects of nCuO on green onion (Allium fistulosum) and surface-coated nTiO2 on full-grown carrot (Daucus carota L.) are still unknown. Green onion is characterized by its high content of the antioxidant allicin, and carrot is a worldwide economic …

Additions To Philippine Slender Skinks Of The Brachymeles Bonitae Complex (Reptilia: Squamata: Scincidae) Iv: Resurrection And Redescription Of Brachymeles Burksi, Cameron D. Siler, Elyse S. Freitas, Jennifer A. Sheridan, Stephanie N. Maguire, Drew R. Davis, Jessa L. Watters, Kai Wang, Arvin C. Diesmos, Rafe M. Brown

School of Earth, Environmental, & Marine Sciences Faculty Publications

The diversity of Philippine amphibians and reptiles has increased over the last few decades, in part due to re-evaluation of species formerly believed to be widespread. Many of these investigations of widespread species have uncovered multiple closely related cryptic lineages comprising species complexes, each restricted to individual Pleistocene Aggregate Island Complexes (PAICs). One group in particular for which widespread cryptic diversity has been common is the clade of Philippine skinks of the genus Brachymeles. Recent phylogenetic studies of the formerly recognized widespread species Brachymeles bonitae have indicated that this species is actually a complex distributed across several major PAICs and …

New County Records Of Amphibians And Reptiles From South Texas, Usa, Clinton J. Guadiana, Padraic S. Robinson, Matthew S. Schalk, Drew R. Davis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Several species of amphibians and reptiles reach their northern range limit in south Texas, USA. Herpetological research in the area, as well as frequent visits from amphibian and reptile enthusiasts, have helped to form a more complete understanding of amphibian and reptile distributions across the region. However, gaps in the recognized distribution of many species remain. Efforts to better document species occurrence are confounded by the lack of public land and the fact that most of south Texas is privately owned, making access to suitable habitat difficult (Schmidly et al. 2001)

Coral Reefs In The Gulf Of Mexico Large Marine Ecosystem: Conservation Status, Challenges, And Opportunities, Diego L. Gil-Agudelo, Carlos E. Cintra-Buenrostro, Jorge Brenner, Patricia Gonzalez-Diaz, William Kiene, Caitlin Lustic, Horacio Perez-Espana

School of Earth, Environmental, & Marine Sciences Faculty Publications

The importance of coral reefs (CR) within marine ecosystems has become widely recognized. Although shallow CR are not as abundant in the Gulf of Mexico (GoM) as in other areas such as the Caribbean, their uniqueness, singularity, isolation, and conservation status make their conservation highly important. Corals and CR, both shallow and deep, are more widely distributed throughout the GoM than previously thought, providing new venues of research but also new challenges for their sustainable management. They are widely present in the three countries circumscribing the GoM (Cuba, Mexico, and the United States). Corals are also distributed throughout different depths, …

Architectonica Karsteni Rutsch, 1934 (Gastropoda: Architectonicidae) In Seamounts Of The Nazca-Desventuradas Marine Park: First Evidence Of An Extant Population In Chilean Waters Since The Miocene, Cynthia M. Asorey, Javier Sellanes, Erin E. Easton, Rüdiger Bieler, Ariadna Mecho

School of Earth, Environmental, & Marine Sciences Faculty Publications

The presence of Architectonicidae in Chile was previously recorded only from fossil material of eight species present during the Lower Miocene, when Architectonica karsteni had a geographic range that extended from Costa Rica to central Chile (34°S). No evidence of the presence of the family in Chile after the Lower Miocene have been reported. As part of this study, we report the discovery of A. karsteni at four seamountsat ~200 m water depth in the recently created Nazca-Desventuradas Marine Park, located ~900 km west of continental Chile. Morphological identification was based on protoconch diameter, coloration patterns, and teleoconch sculpture. We …