Graduate Theses & Dissertations

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Ecosystem Response to Above Canopy Nitrogen Addition in a Jack Pine (Pinus banksiana) Forest in the Athabasca Bituminous Sands Region of Northeastern Alberta, Canada
In this study we seek to better understand the potential effects of short-term (5-year) N fertilization on jack pine forest biogeochemistry, vascular plant community composition and to project a temporal endpoint of nitrogen leaching below the major rooting zone. Aqueous ammonium nitrate (NH4NO3) was applied above the forest canopy across five treatment plots (20 x 80 m) four times annually. The experimental deposition gradient followed those known for localized areas around the major open pit operations at 0, 5, 10, 15, 20 and 25 kg N ha-1 yr-1 over a five-year period (2011 – 2015). Nitrate recovery in throughfall was significantly higher than NH4+ (p < 0.05), indicating canopy NH4+ immobilization. There was a strong treatment effect (p < 0.05) of N on the epiphytic lichen thalli concentrations of Hypogymnia physodes and Evernia mesomorpha after five years. The canopy appeared to approach saturation at the highest deposition load (25 kg N ha-1 yr-1) during the fifth year of N additions as most N added above the canopy was accounted for in throughfall and stemflow. The non-vascular (lichen and moss) vegetation pool above the forest floor was the largest receptor of N as cryptogam foliar and thalli N concentrations showed a significant treatment effect (p < 0.05). Nitrogen in decomposing litter (25 kg N ha-1 yr-1) remained immobilized after five years, while treatments ≤ 20 kg N ha-1 yr-1 started to mobilize. Understory vascular plant cover expansion was muted when deposition was ≥ 10 kg N ha-1 yr-1. Finally, modeling suggests the forest may not leach N below the rooting zone until around 50 years after chronic addition begin (25 kg N ha-1 yr-1). The modeling results are consistent with empirical data from a high exposure (~20 - 25 kg N ha-1 yr-1) jack pine site approximately 12 km west of the experimental site that has not yet experienced N leaching. Author Keywords: Biogeochemistry, Canopy, Deposition, Jack Pine, Nitrogen, Understory
Building social connections
This thesis evaluates a multi-stakeholder participatory planning initiative, NeighbourPLAN, in Peterborough, Ontario, and the role of the third-party broker, GreenUP, in establishing connections and networks of capacity between marginalized members of the community and contributing organizations, city, and experts. Participatory approaches to engage residents disenfranchised by traditional planning processes are believed to challenge the status quo perpetuated by top-down decision-making. I worked within two neighbourhoods involved in NeighbourPLAN to determine whether the collaborative work and brokering between stakeholders would foster increased connectedness that could exist independently and last beyond the project's timeline. The findings from this evaluation determine that, from the residents' perspectives, while the presence of the other stakeholders in these participatory planning events was valuable, there was not enough affective time to create long-lasting connections. Partners that developed relationships marked with trust and mutual benefit provide a helpful blueprint showing how serious commitment and consistency can build sustainable and meaningful connections. I conclude with a set of recommendations to enhance the connection building between diverse stakeholders and marginalized communities within NeighbourPLAN, highlighting the promising potential of arts-based and storytelling methods. Author Keywords: arts-based methods, community engagement, Participatory action research (PAR), participatory planning, photovoice, social connectedness
Tools and Techniques
The tools and techniques used by Ontario’s Middle Woodland potters to create designs on vessels have often been assumed in the literature. Pottery typologies currently use these assumptions to classify ceramics found in the archaeological record. Assumed, or suggested, tools and techniques include cord impression, cord-wrapped stick, fabric impression, fabric-wrapped paddle, incised paddles, unmodified shell, modified shell dentate tools, and leather thong. This thesis presents a series of experiments using replica versions of these tools. The results reveal that they are all viable tools for creating designs during ceramic manufacture. Specifically, incised paddles may have been used to create check-stamped pottery, unmodified shell may have been to create what the literature calls pseudo-scallop shell impressions, and modified shell may have been used to create what the literature calls dentate impressions. Where possible, experimental tiles were compared with examples from the Charleston Lake collection of complete to near complete Middle and Late Woodland vessels from Southeastern Ontario. These comparisons have revealed problems in the current classification and study of the Charleston Lake collection and a need for a re-evaluation of the current typologies used to classify Middle Woodland pottery Author Keywords: ceramic manufacture, cord-wrapped stick, experimental archaeology, Middle Woodland, point peninsula, pseudo scallop shell
Phosphorus delivery in the Rainy-River Lake of the Woods Watershed
Lake of the Woods (LOW) is a large international waterbody which suffers from frequent and widespread algae blooms. Previous studies have highlighted the importance of the lake's largest tributary, the Rainy River (RR) and its significance in total phosphorus (TP) delivery to the LOW. Unfortunately, little is known about TP contributions from the RR and its tributaries within the Canadian portion of the watershed. This thesis examines patterns and sources of TP from four tributaries on the Canadian side of the lower RR region, two of which are predominantly natural, and two that are predominantly agricultural. Relationships between water quality parameters, land use and geologic characteristics were observed over a complete hydrologic year (Oct 1, 2018 - Sept 31, 2019), and through an intensive sampling campaign using a nested watershed approach during the spring high flow and summer low flow periods. Results revealed that TP and total suspended sediment (TSS) concentrations (>100 µg/L and >20 mg/L respectively), and loads (>20 kg/km2 and >3500 kg/km2, respectively), were greater at agricultural sites compared with natural sites (<65 µg/L TP and <15 mg/L TSS concentration, and <20 kg/km2 TP and <4000 kg/km2 TSS export). Total P, TSS, Fe, and Al were significantly positively correlated (R2= 0.26-0.59; p<0.05) and intensive sampling revealed that these relationships were strongest during the spring and at the agricultural sites (R2= 0.73-0.98; p<0.05). In contrast, the summer intensive sampling revealed that TP and redox sensitive Fe were significantly correlated (R2= 0.72; p<0.005), whereas redox insensitive Al and TSS were not, suggesting TP may be sourced via redox processes in the summer due to favourable hydrologic conditions. This was observed not only at sites with high wetland influence, but also at sites with more agricultural presence suggesting that redox sourced TP may also originate from mineral stream bed sediment during low flow periods. This research suggested two primary TP sources in the lower RR region: erosion in the spring, and redox processes (internal release) in the summer. It is recommended that intensive monitoring continue in Canada, and further research be conducted to fully understand the significance of internal P release in the tributaries. Author Keywords: erosion, land use, nutrients, particulates, redox, water quality
After the Ash Fall
Mount Mazama, a large volcano located in the Cascade Range of Oregon, eruptedsome 7,000 cal. years BP. Following the volcanic eruption, a large portion of the northwestern region of the Great Plains of North America was covered by a thick layer of volcanic ash. The present research project is concerned with the impact of this catastrophic event on the subsistence patterns of the northwestern Plains groups during the early Archaic period (ca. 6,600–6,000 BP). More specifically, this research project tests the hypothesis that the eruption of Mount Mazama prompted the adoption of bone grease rendering in this part of the Plains. To test this hypothesis, a faunal analysis of the assemblages of Stampede site, located on the Cypress Hills of southeastern Alberta, was performed. The results of the analysis presented here show that the faunal material of the Stampede site is extensively burnt, which seems to be more in line with the intentional disposal of bones in hearth features, possibly for cleaning purposes, than with bone grease manufacture. The methodological issues regarding the identification of bone grease rendering from archaeozoological assemblages are discussed here. Author Keywords: Bone Grease Rendering, Carcass Processing Behaviour, Faunal Analysis, Great Plains, Northern Plains, Subsistence
Using ultra high-resolution mass spectrometry to characterize the biosorbent Euglena gracilis and its application to dysprosium biosorption
Euglena gracilis is an enigmatic and adaptable organism that has great bioremediationpotential and is best known for its metabolic flexibility. The research done in this dissertation addresses (1) how growth conditions impact cellular composition, and (2) how chemometric approaches (such as statistical design of experiments and artificial neural networks) are viable alternatives to the conventional biosorption models for process optimization. Using high-resolution mass spectrometry for biosorbent characterization is a powerful way to assess the chemical characteristics of lyophilized and fractionated cells with high precision, especially to screen for compound classes that may have potentiality for rare earth element removal. Growth conditions impacted cellular composition and separated size fractions of cells yielded different molecular/chemical properties as described by compositional abundances, thus different biosorptive potential. Untargeted analysis demonstrated that exponential dark-grown cells with glucose supplementation were abundant in polyphenolic- and carbohydrate-like compounds, molecular species highly involved in rare earth element binding. Light grown cells had more heterogeneity and the highest molecular weighted fractions from light grown cells (fraction D) had the most abundances of polyphenolic- and protein-like structures. Chemometric modeling used identified the best and worst conditions for iii dysprosium sorption and showed that pH had the most significant influence on bioremoval. Bioremoval ranged from 37% at pH 8 to 91% at pH 3 at Dy concentration ranging from 1 to 100 μg L-1. The work presented in the PhD dissertation will aid in understanding the chemical characteristics of biosorbents by using a Van krevelen analysis of elemental ratios whether algal cells are grown in different environmental growth conditions, or when algal cell are size fractionated. This is especially applied for the screening for metal binding potentiality to Dysprosium. Chemometric methods provide an alternative method for the investigating factors for bioremoval, and applications for process optimization and for real-world applications. This dissertation will aid in understanding chemical characteristics when a biosorbent is grown in a given condition and which factors are important for rare earth element (REE) bioremoval. The significance of this work aims to look for alternate ways to screen biosorbents and using a more efficient experimental design for REE bioremoval. Author Keywords: bioremoval, biosorption, chemometrics, dysprosium, euglena, mass spectrometry
Unsettling Inner Landscapes
Recent climate scientists, Indigenous resurgence scholars, and psychologists have variously indicated that we need a transformation of consciousness in order to address the cultural and spiritual forces at the root of our current environmental, interpersonal, and individual crises of disconnection. My research is in direct response to diverse calls for this paradigm shift, including the words of Elders such as the late Grandfather William Commanda who encouraged settlers such as myself to ‘remember our original instructions’. Through an anti-colonial and trauma-informed lens, my goal has been to strategically inform my roles and responsibilities in healing the disconnection and abuses in what I term the trilogy of my relationships to self, others, and Land. This study is both a critical auto-ethnography and as well as a theoretical engagement with Indigenous resurgence, settler colonialism, and sustainability discourses. I share dialogues with Anishinaabe-kweg in my community with whom I have established relationships and the results of our discussions focus on holistic models of transforming settler consciousness. What emerges is an emotional, uncertain, and yet radically hopeful narrative that points to the urgency of centering Indigenous sovereignty and Indigenous relationship models while endeavouring to reconstruct a sense of identity and belonging along more accountable lines. Recovering a sense of my Celtic epistemology and story work is offered as a strategic exemplar of how settlers might begin to remember and co-create more balanced, respectful, and reciprocal relationships with and within place. Nurturing an embodied spiritual practice of deep listening, critical self-reflection, and collective action is discussed as potentially central to sustaining a decolonizing praxis for white settler Canadians more broadly. Author Keywords: Critical auto-ethnography, Critical Spirituality, Decolonization, Indigenous-settler relations, Original Instructions, Settler colonial studies
Women's Lived Experience of Risk in Pregnancy
Cardiovascular disease (CVD) prevention, treatment and outcomes in women remain largely inequitable globally. Unique sex-specific stages of life, including pregnancy conditions, and their influence on cardiac risk is a growing area of research (Norris et al., 2020). For example, preeclampsia is strongly associated with CVD risk. This connection has led to prevention interventions such as postpartum risk clinics. Research to date on pregnancy and chronic disease is rooted in the medical paradigm of risk and lacks women’s lived experience. The present study qualitatively explored illness and risk perceptions of women with risky pregnancy conditions. Some participants felt self-blame for their conditions. Consequences and severity were focused on “baby first”, while maternal risk was viewed in the distant future. Aspects of the pregnancy experience, including prompt access to mental health support, was viewed as a “blessing in disguise”. Risks, such as lack of agency, and benefits of healthcare risk communication and intervention and implications for practice were also explored. Author Keywords: communication, critical, health care, phenomenology, pregnancy, risk
Experiences of Seven Deaf & Hard-of-Hearing Alumni of Ontario’s Education System
Through narrative/life story research this study explores the educational experiences of six individuals identified as Deaf or hard-of-hearing. The research presented will be conveyed in the form of an autoethnography, an approach to research and writing that seeks to describe and analyze personal experience to understand cultural experience. I will combine the views of participants who have been part of the Ontario Public School System within the last 10-15 years (2004-2019), with my own educational experience, learning with hearing loss. In this study, three interrelated concepts—student engagement, motivation, and resilience—are examined through the lens of “mindsets.” Mindsets are “assumptions that we possess about ourselves and others that guide our behaviour” (Brooks, 2012, p. 1). The research reviewed in this paper, shows that students’ beliefs about their academic ability can influence their academic tenacity. Academic tenacity refers to the mindsets and skills that enable students to: establish long-term goals and persevere in the face of adversity. I illuminate some of the systemic factors which impact the mindsets of students who are Deaf and hard-of-hearing. The design lies within the qualitative spectrum; data were gathered and analyzed from open-ended interviews conducted with purposively selected participants. Author Keywords: Academic Tenacity, Autoethnography, Deaf, Education, Hard-of-Hearing, Mindsets
Community Coalescence and Regional Geospatial Trends of Ceramic Decorative Variation in Late Woodland Northern Iroquoia
This case study focuses on geospatial patterns of decorative variation in pottery assemblages from 234 Northern Iroquoian village communities, occupied between ca. 1350–1650 CE. Previous interpretations of these assemblages’ ceramic decorative variability have been based on the assertion that potters from these communities used collar decorative motifs as communicative social signals. However, they did not consider whether these geospatial decorative patterns could simply reflect the outcome of stochastic macroscale social learning processes driven solely by probabilistic information exchange between closer neighboring communities. Cultural transmission, the theoretical framework applied here, is well-suited to address this perspective. Thus, the primary research question of this case study is, “Are the expected outcomes of random copying processes sufficient to explain the range of geospatial ceramic decorative variability observed across Northern Iroquoia?” Random copying processes are the stochastic, probabilistic social learning mechanisms driving the collective decisions of multiple communities, making up one side of the “random-selective copying spectrum.” When the decorative decisions of multiple communities are collectively guided by shared ideas (such as, potentially, symbolic communication structures), they become subsumed under the broad umbrella of “selective copying” processes. The social learning mechanisms involved on both sides have predictable geospatial and structural ranges of ceramic decorative patterning. The goal of this case study was thus to evaluate the range of patterning in Northern Iroquoia, both generally as well as at narrower temporal and spatial scales. Ultimately, region-specific temporal trends in selective copying processes seeming to reflect recently established temporal trajectories of community coalescence were identified. Author Keywords: coalescence, cultural population structure, cultural transmission, isolation by distance, Northern Iroquoia, social signaling
Examining the Diet of Early Nomadic Pastoralists in Southern Mongolia Using Carbon and Nitrogen Stable Isotope Analysis
This study reconstructs the diet of pastoral populations from Bronze Age Southern Mongolia and Early Iron Age Central Mongolia using stable carbon and nitrogen isotope analysis of bone collagen from 44 individuals. Spatial and temporal differences were investigated and interpreted in combination with paleoenvironmental, archaeological, genetic and other stable isotope data. The Southern Mongolian diet is consistent with a mixed diet including C3 and C4 plants and large amounts of animal products from herd animals such as sheep/goat, horses and cattle. The δ13C values from Bronze Age Southern Mongolia are consistent with the consumption of C4 plants, most likely millet, obtained through trade with Northern China although environmental aridity might also be responsible for this pattern. The diet was relatively constant over time but spatial differences in Mongolia and Central Asia indicate variation in subsistence strategies based on environmental and cultural context. This thesis highlights the flexibility of pastoralism and its adaptability in the face of environmental and cultural changes. Author Keywords: Bronze Age, carbon and nitrogen isotopes, Mongolia, nomadic pastoralism, paleodiet, stable isotope analysis
Teacher Efficacy as an Indicator of how Mathematics Educators Perceive the Value of Professional Learning Experiences
This study investigates the potential for a responsive model of professional development in mathematics education which acknowledges how teachers perceive the value of professional learning, and examines how those perceptions are connected to teacher efficacy. Three fields of educational research ground this study: (i) professional development strategies in mathematics education, (ii) teacher efficacy, and (iii) self-determination theory and andragogy. Data collection and analysis involved four detailed case studies and a cross-case analysis of similarities and distinctions among the cases, in an instrumental-multiple-case study design. Results suggest: (1) some characteristics of professional development were consistently designated as high or low value, independent of efficacy ratings, (2) other professional learning experiences were valued relative to the participants’ sense of efficacy at different times in their careers, and (3) characteristics of professional development designated as high value during periods of low efficacy were fundamentally teacher-centric, but during periods of high efficacy, they were fundamentally student-centric. Author Keywords: efficacy, mathematics education, mathematics teachers, professional development, professional learning, teacher efficacy

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Graduate student theses produced at Trent University. You may also browse theses and dissertations by year, program, or author.

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1973 - 2033
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