Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Resources and risk are in constant flux and an organism's ability to manage change may improve their likelihood of persistence. I examined intra-seasonal variation in nest-site selection and survival of a declining wetland bird, the Black Tern (Chlidonias niger surinamensis). I modelled nest site occupancy and survival of early and late-nesting birds as a function of static and… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>North American freshwater fishes are declining rapidly due to habitat fragmentation, degradation, and loss. In some cases, translocations can be used to reverse local extirpations by releasing species in suitable habitats that are no longer naturally accessible. Lake sturgeon (Acipenser fulvescens) experienced historical overharvest across their distribution, leading to endangered… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The network composition hypothesis (NCH) suggests that i) large confluence symmetry ratios (drainage area of the tributary relative to the mainstem) and ii) landscape differences (differences in landscape characteristics between the mainstem and tributary drainages) lead to greater ecological changes below confluences. As a test of the NCH, 34 confluences were sampled in southern Ontario… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Preston, Colette Alexia, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): Boulton, Wayne, Degree committee member (dgc): Buttle, James, Degree committee member (dgc): Eimers, Catherine, Degree granting institution (dgg): Trent University Abstract: <p>A series of experiments was designed to assess the relative efficacy of various dust suppressants to suppress PM10 emissions from nepheline syenite tailings. The experiments were conducted in the Trent University Environmental Wind Tunnel, Peterborough, Ontario, and on the tailings ponds at the Unimin Ltd Nephton mine near Havelock, Ontario. Treated surfaces were subjected to particle-… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>To better understand species' resilience to climate change and implement solutions, we must conserve environments that maintain standing adaptive genetic variation and the potential generation of new beneficial alleles. Coding trinucleotide repeats (cTNRs) providing high-pace adaptive capabilities via high rates of mutation are ideal targets for mitigating the decline of species at… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study seeks to clarify the way in which the differing canopy characteristics among tree species influence the partitioning of precipitation, and therefore the source of water available for plant water uptake, in the Plastic Lake catchment near Dorset, ON. Three dominant tree species were compared: red oak (Quercus rubra), eastern white pine (Pinus strobus), and eastern hemlock (… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>According to the Invasional Meltdown Hypothesis (IMH), invasive species may interact in their introduced range and facilitate future invasions. This study investigated the possibility that Alliaria petiolata, an invasive allelopathic herbaceous plant in Ontario, is facilitating invasions by additional alien species. Two allelopathic focal species were chosen for this study: the native… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Wehtje, Morgan, Thesis advisor (ths): Bowman, Jeff, Thesis advisor (ths): Murray, Dennis, Degree committee member (dgc): Fortin, Marie Josee, Degree committee member (dgc): Wilson, Paul, Degree granting institution (dgg): Trent University Abstract: <p>Range contractions and expansions are important ecological concepts for species management decisions. These decisions relate not only to rare and endangered species but to common and invasive species as well. The development of the broad spatiotemporal extent models that are helpful in examining range fluctuations can be challenging given the lack of data expansive enough to cover the… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Increases in flooding due to anthropogenic influences such as climate change and reservoir creation will undoubtedly impact aquatic ecosystems, affecting physical, chemical, and biological processes. We used two approaches to study these impacts: a whole-ecosystem reservoir flooding experiment and a systematic literature review. In the whole-ecosystem experiment, we analyzed the impact… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Leaf litter decomposition represents a major pathway for nutrient cycling and carbon flow in aquatic ecosystems, and macroinvertebrates play an important role in the processing of this material. To assess the causes of variable leaf breakdown and nutrient fluxes, I measured decomposition rates and the nutrient release ratios of decomposing leaf material across a broad latitudinal… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Cytokinins (CKs) are hormones that promote cell division. During the formation of tumors in the Ustilago maydis-Zea mays pathosystem, the levels of CKs are elevated. Although CK levels are increased, the origins of these CKs have not been determined and it is unclear as to whether they promote the formation of tumors. To determine this, we measured the CK levels, identified CK… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Effective population size (Ne) is a foundational concept in conservation biology, in part due to its relationship to the adaptive potential of populations. Although Ne is often estimated for wild populations, it is rarely calibrated against actual population estimates (Nc) other than to produce Ne/Nc ratios. This project used demographic and genetic data for from two intensively-studied… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>While both resource quality and predator-derived chemical cues can each have profound effects on zooplankton populations and their function in ecosystems, the strength and nature of their interactive effects remain unclear. We conducted laboratory experiments to evaluate how stoichiometric food quality (i.e., algal carbon (C):phosphorus (P) ratios) affects responses of the water flea,… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Stream solutes are strongly linked to hydrology, and as such, we sought to better understand how hydrology, particularly flooding, influences nitrogen (N) and phosphorus (P) levels. We used a long-term dataset of monthly water quality samples for many Ontario, Canada, catchments to assess the effects of landscape variables, such as land use and physiography, on the export of nutrients… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Stopover ecology is a topic that surges in relevancy as choices made by migrants during stationary periods (stopover sites) may not only have important individuals' fitness consequences but also can affect population dynamics. I used MOTUS automated telemetry array to study fall stopover duration of Blackpoll Warbler (BLPW) and departure decisions of BLPW and Canada Warbler (CAWA)… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Lock, Alan S., Thesis advisor (ths): Wallschläger, Dirk, Thesis advisor (ths): Belzile, Nelson, Degree committee member (dgc): Belzile, Nelson, Degree committee member (dgc): Gueguen, Celine, Degree granting institution (dgg): Trent University Abstract: <p>A bedrock fracture hosting arsenic (As) contaminated groundwater was suspected to be transported to Ramsey Lake, a drinking water resource for more than 50,000 residents of Sudbury, Ontario. A high resolution, spatial, water quality mapping technique using an underwater towed vehicle (UTV) was used to identify sources of upwelling groundwater into lake water and localize the upwelling As… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The predator vs. prey dynamic is an omnipresent factor in ecological systems that may drive changes in life history patterns in prey animals through behavioural, morphological, and physiological changes. Predation risk can have profound effects on the life history events of an animal, and is influenced by the neuroendocrine stress response. Activation of the hypothalamic-pituitary-… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>A catchment-based study was carried out at three remote acid sensitive Irish lakes to determine concentrations of Hg and POPs and to investigate the factors governing the partitioning of these pollutants in various environmental matrices. Both Hg and POPs are an environmental concern due to their ability to travel long distances via atmospheric transport and their tendency to accumulate… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Paleczny, Andrea Rose, Thesis advisor (ths): Emery, Neil, Degree committee member (dgc): Yee, Janet, Degree committee member (dgc): Saville, Barry, Degree committee member (dgc): Olechowski, Henry, Degree granting institution (dgg): Trent University Abstract: <p>Cytokinins (CKs) are a family of plant phytohormones responsible for many areas of plant growth and development. There are four free base types of CKs found in higher plants, trans-zeatin (tZ), N6-(∆2-isopentenyl)adenine (iP), cis-Zeatin (cZ) and dihydrozeatin (DZ). CK biosynthesis is regulated by adenosine phosphate-isopentenyltransferase (IPT), which is encoded by a multi-gene family… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study was designed to determine the geochemistry and potential toxicity of water draining a large slag pile in Sudbury, Ontario, which runs through a pond complex prior to entering Alice Lake. Slag leaching experiments confirmed slag is a source of sulphate, heavy metals (including Fe, Al, Ni, Co, Cu, Zn, Pb, Cr, Mn) and base cations (Ca, K, Mg, Na). Concentrations of most metals… more