Soil Science Commons^™

Impacts Of Burn Severity On The Hydro-Physical, Chemical And Thermal Properties Of Sub-Arctic Peat, Joshua B. Meyer Mr

Theses and Dissertations (Comprehensive)

Under current climate change, summer season in the boreal regions of Canada is becoming increasingly warmer and drier. This shift is driving increases in the frequency and intensity of naturally occurring wildfires and allowing access to areas not normally susceptible to fire such as wetlands. In peatland areas, these increasingly large fires can create complex burn scars, which contain a wide variety of different burn severities across different landcover types. This variety calls for a greater understanding of how varying fire intensity affects the hydro physical, chemical, and thermal characteristics of boreal peat. This study aims to deepen that understanding …

Controls On Thermokarst Lake Water Balances In The Inuvik - Tuktoyaktuk Region, Evan J. Wilcox

Theses and Dissertations (Comprehensive)

There are tens of thousands of thermokarst lakes in the Inuvik-Tuktoyaktuk region, located in the northwest corner of the Northwest Territories, Canada. These lakes formed following the last glacial period in areas where ice-rich permafrost thawed and created depressions in the landscape. The Inuvik-Tuktoyaktuk region is one of the fastest warming regions in the world, leading to changing precipitation patterns, permafrost thaw and deciduous shrub expansion, all of which are affecting the water balance of thermokarst lakes. During the past several decades, lake expansion and contraction have been observed in response to fluctuations in precipitation. While these changes in lake …

Evaluating The Biogeochemical Functioning Of A Constructed Fen On The Post-Mining Landscape Of Athabasca Oil Sands Region, Fort Mcmurray, Alberta, Canada, Felix C. Nwaishi

Theses and Dissertations (Comprehensive)

Peatlands have a unique biogeochemical function, characterized by an imbalance between the rates of biomass accumulation and decomposition. These characteristics facilitate the ability of peatlands to support the sequestration of nutrients and carbon. In disturbed peatlands, these functions are compromised. Thus, reclamation targets amongst other key functions, the recovery of biogeochemical functioning. These functions could serve as a measure of recovery to conditions that are present in natural analogues. This thesis examines the recovery of microbially-mediated nutrient transformation processes in a fen peatland that was constructed on a post-mining landscape in the Athabasca oil sands region, Fort McMurray, Alberta. The …

Spanish River Carbonatite: Its Benefits And Potential Use As A Soil Supplement In Agriculture, James J

Theses and Dissertations (Comprehensive)

A critical problem facing agriculture today is being able to consistently and sustainably provide plants with adequate nutrients for growth. With this problem being exacerbated by the ever-increasing human population, new perspectives and techniques are required to ensure global food security. In order to fully realize potential solutions, however, plant growth and nutrition cannot be exclusively focused upon. The soil-microorganism-plant system is comprised of many interconnected and interdependent processes that together support plant growth: it is upon these processes that the focus must be placed. In this work, the agromineral Spanish River Carbonatite (SRC) is characterized using the framework of …

Atr-Ftir Studies On The Kinetics Of Dimethylarsinic Acid (Dma) Surface Complexation With Iron(Oxyhydr)Oxides, Julia Tofan-Lazar Miss

Theses and Dissertations (Comprehensive)

Dimethylarsinic acid (DMA) is an organoarsenical compound that, along with monomethylarsonic acid, poses a health and an environmental risk, and a challenge to the energy industry. Little is known about the surface chemistry of DMA at the molecular level with materials relevant to geochemical environments and industrial sectors. The surface chemistry of phosphorus and arsenic compounds in their organic and inorganic forms is of great interest due to its role in controlling their transport, bioaccessibility and speciation. This thesis reports the first in-situ and surface-sensitive rapid kinetic studies on the adsorption and desorption of DMA to and from Fe-(oxyhydr)oxide films …

Spatial And Temporal Patterns In Nitrous Oxide Flux From Agricultural Soil In Southern Ontario, Michelle E. Zurbrigg

Theses and Dissertations (Comprehensive)

This research examines spatial and temporal variations in N₂O flux from agricultural clay loam in corn-wheat and corn-oat rotations in southern Ontario. Gas samples are collected by the chamber method following significant precipitation events, thaw events, fertilization events, and otherwise every two weeks over a two-year period. Crop type appears to influence the magnitude of N₂O emisions, whereas N₂O fluxes do not otherwise seem to vary by landscape position. The seasonal pattern of in situ N₂O flux at Strawberry Creek (SC) indicates that the highest N₂O emissions are occuring during …

Plant Isotopes As Indicators Of N Cycling Processes In Agricultural Fields, Eric Thuss

Theses and Dissertations (Comprehensive)

When nitrogen (N) availability exceeds biological demand, excess N, especially nitrate (NO₃), may subsequently pollute ground and surface water. Agricultural practices in Southern Ontario typically supplement soils with organic and inorganic nutrients to aid in crop development, and employ various management techniques to limit nutrient loss. Excess N has several potential fates, which are controlled by the net effects of numerous N cycling reactions in the soil that are often difficult to measure directly. N cycling in soils is controlled in large part by soil moisture, as it affects microbial activity and soil redox conditions. Stable isotope geochemistry …

Variability Of Metals In Soils In The Sudbury Area (Ontario), Vera Spektor

Theses and Dissertations (Comprehensive)

Industrial development influences the natural and human environment. At the local scale, the most intensive industrial pollution is in the area of factories and industrial centers. Industrial pollution is concentrated in soil and vegetation (then, using water systems and trophic chains it may enter all ecosystem components). The industrial pollution of the Sudbury region includes mostly sulfur dioxide and heavy metals. The main goal of this study was to examine spatial variability in metal distribution in soil for the Sudbury area. Objectives of the work were to describe metal distribution depending on geographic factors such as topographic location, vegetation cover, …

Spatial Distribution Of Lead In Soil And Sediment In Iqaluit, Northwest Territories And Links With Human Health, Liisa Ann Peramaki

Theses and Dissertations (Comprehensive)

The Baffin Regional Health Board has recently expressed concern over lead poisoning in Iqaluit, NWT, manifested by low haemoglobin levels in children. Several studies in temperate regions have demonstrated links between environmental lead and human health. However, little is known about these links in a permafrost environment. While humans are exposed to lead via a number of different pathways, soils and sediments are two major pathways. The purpose of this study is to determine the spatial distribution of soil and sediment-associated lead in Iqaluit and to assess probable pathways between high lead levels and children. The research hypothesis is that …

Relative Rates Of Sand Transport Through An Incipient Parabolic Dune At Pinery Provincial Park, Ontario (Ammophila Breviligulata, Calamovilfa Longifolia, Cakile Edentula, Juniperus Virginiana, Populus Deltoides), Sheri A. Longboat

Theses and Dissertations (Comprehensive)

Factors controlling the development, migration, and stability of an incipient parabolic dune in Pinery Provincial Park, Ontario were investigated in terms of grain size characteristics, rates of sediment transport, and local and regional winds. The parabolic dune, situated approximately 60 meters inland of Lake Huron, is dominated by sparsely scattered dune grass species of marram grass (Ammophila breviligulata), sand reed (Calamovilfa longifolia), and sea rocket (Cakile edentula). Small tree species of red cedar (Juniperus virginiana) and eastern cottonwood (Populus deltoides) emerge and increase in number beyond the parabolic dune. Mean grain sizes along a profile were coarsest on the beach …

The Effect Of Particle Size On Phosphate Adsorption By Fluvial Sediment, Michael F.A. Stone

Theses and Dissertations (Comprehensive)

The quantitative phosphate adsorption behaviour of ten grain size fractions of an experimental sediment (silica sand) and fluvial sediment from two Southwestern Ontario rivers, were evaluated and compared to determine the effect of particle size on phosphate absorption. In addition, the elemental composition of grain size fractions of fluvial sediment were determined by X-Ray fluorescence spectrometry to study the combined effect of particle size and sediment geochemical composition on phosphate adsorption. Results of the adsorption studies indicate that phosphate adsorption per unit mass increases in non-linear fashion with decreasing grain size. The capacity of grain size fractions of silica sand …

Flume Experiments On Bedforms And Structures At The Dune-Plane Bed Transition, Francis P.J. Lockett

Theses and Dissertations (Comprehensive)

A tiltable, recirculating flume, 18 metres long and 76 cm. wide was used to investigate bedforms and structures near the transition between dunes and a plane bed for a moderately sorted, coarse sand. At Froude numbers ranging from about 0.4 to 1.0, three dune types developed: (1) asymmetrical (triangular) dunes, (2) convex (symmetrical) dunes and (3) humpback (whaleback) dunes. Asymmetrical dunes had gentle, long stoss sides and steep, short lee sides and contained cross-stratification with a maximum dip mostly about 30 degrees to 35 degrees. Flow separation and avalanching were strongly developed to the lee of these dunes. Convex dunes …

A Field Study Of Infiltration On Various Agricultural Soils, Stephen J. Stephen

Theses and Dissertations (Comprehensive)

The purpose of the study was to ascertain if infiltration and temperature varied significantly among the selected soil types of the Smithfield, Otonabee, Wendigo and Farmington Series. These data were gathered from field tests performed during the summer months in Ontario and Victoria Counties.

A stopwatch was used to measure the number of seconds that were required for 0.8 inches of water to disappear into the soil inside a 4 inch diameter single ring infiltrometer which had been placed one inch into the soil surface. The soil temperature was recorded at the same time.

The sites were chosen by stratified …