Graduate Theses & Dissertations

Pages

Investigation of Air Recirculation and Thermal Efficiency within a Climate Controlled Passage
Historically, entrances have been used for passage between two separate temperature environments, such as moving from inside to outside of a building. Energy loss through entrances is a cause for concern, as it has been known to increase energy consumption to replace the lost energy; and with the exchange of air masses and cold air entering the building, human discomfort may occur. In this research, thermal efficiency and air circulation within a Conventional Entrance (CE) and Climate Controlled Passage (CCP) are compared. A small scale model of the CE and CCP was constructed to examine forty-eight energy exchange conditions, emulating those found through an entrance between a temperature controlled lab and the model. Instruments such as a power meter, a flow explorer laser Doppler anemometer, and thermocouples were used to measure and compare the energy consumption, velocity vectors, and temperature energy within the entrance. Results indicate that the CCP did retain thermal energy compared to the CE. The CE developed sloped isotherm lines and air flow that enabled and maintained thermal exhaust. Conversely, the CCP developed horizontal isotherm lines and a two-layer density current to recirculate and retain thermal energy. The research demonstrates that it is possible to increase energy efficiency of entrances in many applications. Author Keywords: Air Recirculation, Building, Entrance, Oven, Thermal Energy Efficiency, Two-layer Density Current
Modelling Monthly Water Balance
Water balance models calculate water storage and movement within drainage basins, a primary concern for many hydrologists. A Thornthwaite water balance model (H2OBAAS) has shown poor accuracy in predicting low flows in the Petawawa River basin in Ontario, so lake storage and winter snow processes were investigated to improve the accuracy of the model. Lake storage coefficients, represented by the slopes of lake stage vs. lake runoff relationships, were estimated for 19 lakes in the Petawawa River basin and compared on a seasonal and inter-lake basis to determine the factors controlling lake runoff behaviour. Storage coefficients varied between seasons, with spring having the highest coefficients, summer and fall having equal magnitude, and winter having the lowest coefficients. Storage coefficients showed positive correlation with lake watershed area, and negative correlation with lake surface area during summer, fall, and winter. Lake storage was integrated into the H2OBAAS and improved model accuracy, especially in late summer, with large increases in LogNSE, a statistical measure sensitive to low flows. However, varying storage coefficients with respect to seasonal lake storage, watershed area, and surface area did not improve runoff predictions in the model. Modified precipitation partitioning and snowmelt methods using monthly minimum and maximum temperatures were incorporated into the H2OBAAS and compared to the original methods, which used only average temperatures. Methods using temperature extremes greatly improved simulations of winter runoff and snow water equivalent, with the precipitation partitioning threshold being the most important model parameter. This study provides methods for improving low flow accuracy in a monthly water balance model through the incorporation of simple snow processes and lake storages. Author Keywords: Lake Storage, Model Calibration, Monthly Water Balance, Petawawa River, Precipitation Partitioning, Snow Melt
Shorebird Habitat Use and Foraging Ecology on Bulls Island, South Carolina During the Non-Breeding Season
Recent declines in North American shorebird populations could be linked to habitat loss on the non-breeding grounds. Sea-level rise and increased frequency of coastal storms are causing significant erosion of barrier islands, thereby threatening shorebirds who rely on shoreline habitats for foraging. I conducted shorebird surveys on Bulls Island, South Carolina in the winters of 2018 and 2019 and examined habitat selection and foraging behaviour in Dunlin (Calidris alpina), Sanderling (Calidris alba), Semipalmated Plovers (Charadrius semipalmatus), and Piping Plovers (Charadrius melodus). Area, tidal stage, and invertebrate prey availability were important determinants of shorebird abundance, behaviour, and distribution. My study highlights the importance of Bulls Island’s habitat heterogeneity to supporting a diverse community of non-breeding shorebirds. Considering both the high rate of erosion and the increased frequency of disturbance along the shoreline of the island, intertidal habitats should be monitored to predict negative effects of changes in habitat composition and area on non-breeding shorebirds. Author Keywords: foraging behaviour, habitat loss, habitat selection, invertebrate prey, non-breeding, shorebirds
Discriminating grey wolf (Canis lupus) predation events in a multi-prey system in central Saskatchewan
I investigated if spatio-temporal behaviour of grey wolves (Canis lupus) determined via GPS collar locations could be used to discriminate predation events generally, and among prey species, in Prince Albert National Park during winter, 2013-2017. I used characteristics of spatio-temporal GPS clusters to develop a predictive mixed-effect logistic regression model of which spatial clusters of locations were wolf kill sites. The model suffered a 60 % omission error when tested with reserved data due to the prevalence of deer kills with correspondingly low handling time. Next, I found a multivariate difference in the percentage of habitat classes used by wolves in the 2 hours preceding predation events of different prey species, suggesting that wolf habitat use reflects prey selection at a fine-scale. My results highlight the difficulty and future potential for remoting discriminating wolf predation events via GPS collar locations in multi-prey ecosystems. Author Keywords: Canis lupus, GPS clusters, GPS collars, grey wolf, habitat use, predation
multi-faceted approach to evaluating the detection probability of an elusive snake (Sistrurus catenatus)
Many rare and elusive species have low detection probabilities, thereby imposing unique challenges to monitoring and conservation. Here, we assess the detection probability of the Eastern Massasauga (Sistrurus catenatus) in contrast to a more common and conspicuous species, the Eastern Gartersnake (Thamnophis sirtalis). We found that patterns of detection probability differed between species, wherein S. catenatus was detected less often and under a more specific set of sampling conditions. Correspondingly, detection trials with S. catenatus found a high non-detection rate, while detection trials with artificial models suggest that regional differences in detection probability are driven by variation in population density and habitat use. Our results suggest that current monitoring efforts are not sufficient, and that S. catenatus is frequently undetected. Accordingly, we highlight the importance of species-specific monitoring protocols when monitoring rare and elusive species, and recommend a multi-faceted approach that estimates detection probability and identifies species-specific challenges to monitoring. Author Keywords: detection probability, elusive species, monitoring programs, non-detection, S. catenatus, snakes
Effects of Local, Landscape, and Temporal Variables on Bobolink Nest Survival in Southern Ontario
Populations of grassland birds, including the Bobolink (Dolichonyx oryzivorus), are experiencing steep declines due to losses of breeding habitat, land use changes, and agricultural practices. Understanding the variables affecting reproductive success can aid conservation of grassland species. I investigated 1) whether artificial nest experiments accurately estimate the impacts of cattle on the daily survival rate of Bobolink nests and 2) which local, landscape, and temporal variables affect daily survival rate of Bobolink nests in Southern Ontario. I replicated an artificial nest experiment performed in 2012 and 2015 to compare the daily survival rate of artificial and natural nests at multiple stocking rates (number of cattle × days × ha-1). I also monitored Bobolink nests and modeled daily survival rate using local variables (e.g., stocking rate, field use, patch area), landscape variables (e.g., percent forest within 2, 5, and 10 km), and temporal variables (e.g., year, date of season). Results indicate that artificial nest experiments using clay shooting targets overestimated the impacts of stocking rate on the daily survival rate of Bobolink nests. With natural nests, region (confounded by year and field use), stocking rate, and date of season were the strongest predictors of daily survival rate; with stocking rate and date of season both having a negative effect. Management should focus on conserving pastures with low stocking rates (< 40 cattle × days × ha-1), late-cut hayfields, fallow fields, and other grasslands to protect breeding grounds for the Bobolink and other declining grassland bird species. Author Keywords: Bobolink, Daily survival rate, landscape variables, local variables, Nest survival, temporal variables
Indirect Effects of Hyperabundant Geese on Sympatric-Nesting Shorebirds
Rising populations of Lesser Snow and Ross’ geese (hereafter collectively referred to as light geese) breeding in the North American Arctic have caused significant environmental change that may be affecting some populations of nesting shorebirds, which in contrast to geese, have declined dramatically. In this thesis I examine the indirect effects of light geese on sympatric-nesting shorebirds. I first conduct a literature review of the effects of light geese on northern wildlife and outline multiple mechanisms in which geese may affect shorebirds in particular. Using bird survey data collected in plots situated across the Canadian Arctic from 1999 to 2016, I then identify spatial effects of light goose colonies on shorebird, passerine, and generalist predator densities. The densities of cover- nesting shorebirds and passerines were depressed near goose colonies while the densities of open-nesting shorebirds were less so. Next, using habitat data collected at random sites and shorebird nest sites situated at increasing distances from a goose colony on Southampton Island, Nunavut, I outline the effects of geese on shorebird nest site selection. I found that the availability of sedge meadow and amount of lateral concealment increased as a function of distance from goose colony; cover-nesting shorebirds selecting nest sites with less concealment and sedge meadow near the colony. Then, to characterize spatial effects of light geese on predators and risk of predation I used time-lapse cameras and artificial shorebird nests placed at increasing distances from the goose colony. Activity indices of gulls, jaegers, and foxes were all negatively correlated with distance from the goose colony while the reverse was true for artificial nest survival probability. Finally, I relate changes in ground cover to goose use and link these changes to variation in invertebrate communities. I then use DNA metabarcoding to characterize the diet of six shorebird species across study sites and identify inter-site variation in the biomass of dominant shorebird prey items. Prey item biomass was elevated at the two study sites near the goose colony potentially indicating an enhancing effect of goose fecal deposition. Overall, I show that light geese interact with shorebirds in multiple ways and negatively affect their habitat availability, nest site selection, and risk of predation, effects that likely outweigh the positive effects of enhanced prey availability. Author Keywords:
Fingerprinting of dissolved organic matter and copper ligands in the Canadian Arctic and North Pacific Ocean
Dissolved organic matter (DOM) in oceans provides nutrients and ultraviolet radiation protection to microbes. Some DOM compounds can chelate with metals, including copper, controlling their transport and bioavailability in marine systems. As copper functions as both a nutrient and toxicant, studies into the chemical structures of Cu-ligands is important, however currently limited. In this thesis, the chemical composition of total and Cu-binding DOM is investigated using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in the Canadian Arctic and North Pacific. Chapter 2 reveals chemical differences in DOM composition between the southern and northern Canada Basin, revealing the influence of terrestrial and biological sources. Chapter 3 shows the uniqueness of Cu-binding ligands found in the Canadian Arctic and North Pacific Ocean. Studying the composition of DOM gives insight into the chemical diversity of marine DOM, helping to predict the effects of a changing climate on marine ecosystems. Author Keywords: biological, dissolved organic matter, fluorescence, immobilized metal-ion affinity chromatography, mass spectrometry, terrestrial
Expression optimization and NMR spectroscopy of Giardia intestinalis cytochrome b5 isotype III
The parasitic protist Giardia intestinalis does not synthesize heme and lacks many common eukaryotic heme proteins, yet it expresses four cytochrome b5 (gCYTB5) isotypes of unknown function. These have low reduction potentials and distinct subcellular locations that are consistent with structural features and biological functions that differ from their mammalian counterparts. Isotype III (gCYTB5-III) is particularly fascinating for its unusual location in the nuclei of Giardia. This thesis reports the optimization of recombinant gCYTB5-III overexpression for structural studies by NMR spectroscopy. Vital optimization factors for isotope labelling were first identified, finding that auto-induction promotes the optimization of many other conditions, such as colony selection, starter cultures, media components, temperature, pH and aeration. Optimized conditions were then applied to the expression and NMR spectroscopy of isotope-labelled gCYTB5-III and bovine cytochrome b5 as a control. These results can be extended to other heme proteins and will expand our biochemical knowledge of Giardia. Author Keywords: Auto-induction, Cytochrome b5, Giardia intestinalis, Isotope Labelling, Nuclear Magnetic Resonance Spectroscopy, Recombinant Protein
Detectability and its role in understanding upland sandpiper (Bartramia longicauda) occurence in the fragmented landscape of southern Ontario
Upland Sandpipers (Bartramia longicauda), like many grassland birds, are undergoing population decline in parts of their range. Habitat fragmentation and change have been hypothesized as potential causes of decline. I used citizen-science occurrence data from Wildlife Preservation Canada’s Adopt-A-Shrike Loggerhead Shrike (Lanius ludovicianus) program in conjunction with validation surveys, using similar point-count methods, to examine detectability and determine if landscape level habitat features could predict occupancy of Upland Sandpipers in Southern Ontario. In a single season detectability study, I used Wildlife Preservation Canada’s survey protocol to determine detectability in sites that were known to be occupied. Detectability was low, with six surveys necessary to ensure detection using a duration of at least 18 minutes early in the breeding season. The proportion of open habitat did not affect detection on the landscape. Using a larger spatial and temporal scale, with five years of citizen-science data, I showed that Annual Crop Inventory data could not effectively predict Upland Sandpiper occupancy. Model uncertainty could be attributed to survey protocol and life history traits of the Upland Sandpiper, suggesting that appropriate survey methods be derived a priori for maximizing the potential of citizen-science data for robust analyses. Author Keywords: Bartramia longicauda, citizen-science, detection, landscape, occupancy, Ontario
Making eDNA count
Environmental DNA (eDNA) is rapidly becoming an established method for the detection of species in aquatic systems and has been suggested as a promising tool to estimate species abundance. However, the strength of the relationship between eDNA concentrations and taxon abundance (density/biomass) can vary widely between species. I investigated the relationship between eDNA concentration and species abundance using two common and closely-related amphibians in eastern North America, the wood frog (Rana sylvatica) and northern leopard frog (Rana pipiens). I manipulated tadpole density in 80 L mesocosms and documented the relationship between tadpole density, biomass, and eDNA concentration. Species were comparable in biomass but differed in the amount of detectible genetic material produced; density and biomass were the superior abundance metric correlated with eDNA concentration for wood frogs and leopard frogs, respectively. However, increases in eDNA concentration reflected increasing tadpole biomass, therefore biomass is likely a better metric of abundance than density. Overall my findings support that eDNA concentration can be used as an index of species abundance, but that species-specific calibration may be needed before eDNA concentration can be effectively translated to an abundance metric. Future research should refine our understanding of how biotic and abiotic factors influence eDNA production, degradation, and recovery across species, before the method can receive widespread use as a monitoring tool in natural settings. Author Keywords: abundance estimates, environmental DNA, mesocosm, Rana pipiens, Rana sylvatica
Observation-based assessment of atmospheric sulphur surrounding a major aluminum smelter in British Columbia, Canada
Recent developments at an aluminum (Al) smelter in Kitimat, BC resulted in a permitted increase of 27 to 42 tonnes of sulphur dioxide (SO2) emissions per day. Gaseous SO2 is a pollutant known to contribute to acidic deposition through processes of wet and dry deposition and can additionally react in-atmosphere to form particulate sulphate (pSO42-). Between June 2017 to October 2018, an extensive network consisting of ion exchange resin (IER) column, passive-diffusive, and active filter-pack samplers was established to provide an estimate of total annual S deposition and pSO42- variation throughout the Kitimat Valley. Filter-pack sampling determined the relative concentration of pSO42- increased downwind of the smelter. Comparison of observation-based and modelled total annual deposition suggested CALPUFF was accurate in representing the spatial viability of S deposition (R2 = > 0.85). However, the model appeared to overpredict near-field deposition suggesting the potential of underestimation further downwind of the smelter. Author Keywords: aluminum smelter, atmospheric deposition, filter-pack sampler, ion-exchange column sampler, pSO42-, SO2

Pages

Search Our Digital Collections

Query

Enabled Filters

  • (-) = Environmental and Life Sciences

Filter Results

Date

2009 - 2029
(decades)
Specify date range: Show
Format: 2019/10/21

Author Last Name

Show more

Last Name (Other)

Show more