Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Agricultural and urban land uses have been linked to the recent resurgence of eutrophication and salinization issues in the lower Great Lakes. This thesis examined the relationship between watershed land use and stream nitrate-nitrogen (NO3-N), total phosphorus (TP), and chloride (Cl) concentrations across southern Ontario. Using a self-organizing map analysis, the watersheds were… more Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Eutrophication is an ongoing global problem and agriculture is an important non-point source of nutrient loading. Specifically, nitrogen (N) and phosphorus (P) losses from agricultural landscapes continue to drive water quality issues. In southern Ontario, agriculture has intensified in recent decades, with major expansions of cash crop production and extensive tile drainage (TD).… more Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>In Ontario, farmers commonly use a MZ (Maize (Zea mays L.))-SB (Soybean (Glycine max))/WW (Winter wheat (Triticum aestivum)) – CC (mixed cover crop) rotation to maximize economic benefits. This study aimed to investigate the short-term impacts of the crop rotation phases and their associated management practices in this diversified cash crop rotation on soil health and the abundance of… more Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Glyphosate burndown and tillage, followed by the cultivation of cash crops, are frequently used techniques in LUC from perennial cropping systems (PS) to annual cropping systems (AS). Agricultural LUC can result in the loss of soil nitrogen (N) via emission of nitrous oxide (N2O), a potent greenhouse gas (GHG). The purpose of this thesis is to investigate the short-term impacts of… more Year: 2023, 2023
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The accelerated recovery of base-poor soils from the legacy effects of acidic deposition may be possible by applying industrial wood ash as a soil amendment. Wood ash may be an effective soil amendment due to its high alkalinity and concentrations of several essential nutrients, such as calcium, magnesium, potassium, and phosphorus, that are retained after the volatilization of the… more Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): DeBues, Max, Thesis advisor (ths): Eimers, Catherine, Degree committee member (dgc): Watmough, Shaun, Degree committee member (dgc): Mohamed, Mohamed, Degree committee member (dgc): Mueller, Jessica, Degree granting institution (dgg): Trent University Abstract: <p>Row crop agriculture and associated land use practices including tile drainage and conservation tillage have been cited as a probable cause of re-emerging eutrophication in the
lower Great Lakes. In this thesis, I sought to quantify and evaluate the effect of agricultural land
cover and land use changes on total phosphorus (TP) and nitrate-nitrogen (NO3-N)
concentrations and export in… more Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>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… more Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Decades of acidic deposition have depleted base cation pools in soil over large parts of eastern north America, including the Muskoka-Haliburton region of central Ontario. This region has also experienced a shift in forest species composition over the past 200 years, favouring sugar maple (Acer saccharum Marsh.) at the expense of species such as white pine (Pinus strobus L.) and eastern… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This thesis examines how dissolved organic matter quantity and quality and nutrients influence the flux potential of greenhouse gases (GHG) from sediments collected from streams across southern Ontario as well as Lake Erie. Sediments were collected and incubated in a laboratory setting where headspace gases and interstitial waters were analyzed. Results demonstrated that nutrients (… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Thawing permafrost due to increasingly warm temperatures in northern subarctic regions is releasing mercury. The consequent formation of thaw ponds in the peatland palsa valley of the Sasapimakwananisikw (SAS) river in Whapmagoostui-Kuujjuarapik, Québec may provide a pool for MMHg formation and a potential risk to aquatic and human life, if these ponds facilitate MMHg export through… more Year: 2019, 2019
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The spatial and temporal variation in atmospheric nitrogen dioxide (NO2), ammonia (NH3), and 17 elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, Pb, Mg, Al, Ca, Co, Se, Sb, Mn, and Na) were measured at 40 road side locations along a ~250 km traffic density gradient of 40,000–400,000 vehicles on the King's Highway 401, in Ontario, Canada. Elemental concentrations were measured over a year,… more Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Levasseur, Patrick, Thesis advisor (ths): Watmough, Shaun, Degree committee member (dgc): Aherne, Julian, Degree committee member (dgc): Eimers, Catherine, Degree committee member (dgc): Whitfield, Colin, Degree granting institution (dgg): Trent University Abstract: <p>In 2012, the Rio Tinto aluminum smelter in Kitimat, British Columbia increased sulphur dioxide (SO2) emissions from 27 to 42 tonnes/day. An initial study was conducted to investigate the effect of the increased sulphur (S) deposition on forest soils. A key uncertainty of the initial study was mineral surface area estimations that were applied to critical load calculations. The current… 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>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>Timber harvest can influence the rate of transfer of organic matter from the terrestrial catchment to streams, which may have both direct and indirect effects on in-stream nutrient pools and dynamics. In the interest of developing sustainable forestry practices, the continued study of the effects of forestry on nutrient dynamics in aquatic systems is paramount, particularly in sensitive… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Tree harvesting alters nutrient cycling and removes nutrients held in biomass, and as a result nutrient availability may be reduced, particularly in naturally oligotrophic ecosystems. Selection harvesting is a silvicultural technique limited to tolerant hardwood forests where individual or small groups of trees are removed creating a "gap" in the forest canopy. In order for… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This thesis proposes an agro-ecological zoning (AEZ) methodology of southern Ontario for the characterization and mapping of agro-ecological zones during the historical term (1981-2010), and their shifts into the long-term (2041-2070) projected climate period. Agro-ecological zones are homogenous areas with a unique combination of climate, soil, and landscape features that are important… more Year: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Phosphorus (P) is an essential macronutrient. In south-central Ontario, foliar P concentrations are low and studies have suggested that P may be limiting forest productivity. Current catchment mass balance estimates however, indicate that P is being retained suggesting that P should not be limiting to tree growth. Phosphorus deposition is measured using bulk deposition collectors, which… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Soil mineralizable nitrogen (N) is the main component of soil N supply in humid temperate regions and should be considered in N fertilizer recommendations. The objectives of this study were to determine the potentially mineralizable N parameters, and improve N fertilizer recommendations by evaluating a suite of soil N tests in southwestern Ontario. The study was conducted over the 2013… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Extensive research has gone into measuring changes to the carbon storage capacity of Arctic terrestrial environments as well as large water bodies in order to determine a carbon budget for many regions across the Arctic. Inland Arctic waters such as small lakes and ponds are often excluded from these carbon budgets, however a handful of studies have demonstrated that they can often be… more
