Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Long-term avian population declines, particularly for the avian insectivore guild, are a conservation concern. With widespread and continuing population trends, climate change and its negative effects on avian food resources is a plausible cross-species driver. My goal was to evaluate whether bottom-up trophic effects of climate change could be influencing avian populations. I used a… 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: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Sudbury, Ontario is an epicenter of research on industrially degraded landscapes. Regreening efforts over the past 40 years have changed the landscape, leading to an increase in forest cover in the "barrens", that once covered more than 100,000 ha. This study characterized changes in plant and insect composition using a space for time approach in the pine plantations. A total… more Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): McDonough, Andrew Michael, Thesis advisor (ths): Watmough, Shaun A, Degree committee member (dgc): Aherne, Julian, Degree committee member (dgc): Hutchinson, Tom, Degree committee member (dgc): Sager, Eric, Degree granting institution (dgg): Trent University Abstract: <p>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… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>One possible solution to acidification and losses of base cations in central Ontario forest soils may be the application of wood ash. Wood ash is generally high in pH and contains large amounts of calcium (Ca) and other nutrients essential for ecosystem health, however it also contains trace metals. Understanding the chemistry of soils following ash application to forests is crucial for… more Year: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Improving current understanding of the factors that control soil carbon (C) dynamics in forest ecosystems remains an important topic of research as it plays an integral role in the fertility of forest soils and the global carbon cycle. Invasive earthworms have the potential to alter soil C dynamics, though mechanisms and effects remain poorly understood. To investigate potential effects… more Year: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Arctic terrestrial ecosystems have experienced substantial structural and compositional changes in response to warming climate in recent decades, especially the expansion of shrub species in Arctic tundra. Climatic and vegetation changes could feedback to the global climate by changing the carbon balance of Arctic tundra. The objective of this thesis was to investigate the influence of… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Total phosphorus (TP) concentrations have declined in many lakes and streams across south- central Ontario, Canada over the past three decades and changes have been most pronounced in wetland-dominated catchments. In this study, long-term (1980-2007) patterns in TP concentrations in streams were assessed at four wetland-dominated catchments that drain into Dickie Lake (DE) in south-… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Decreasing lake calcium (Ca) concentration, in lakes located in base poor</p><p>catchments of the Muskoka River Watershed (MRW) in south-central Ontario, is a well- established acid-rain driven legacy effect threatening the health and integrity of aquatic ecosystems that can be compounded by additional Ca removals through forest harvesting. The objectives of this thesis were… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The damage to Sudbury's landscape from over a century of smelter and logging activity has been severe and impacts well documented. However, despite their abundance in the region, wetlands have received little attention. Recent studies have identified that nutrient limitation is as much a problem as metal toxicity and highlighted not only the importance of wetlands but also the need… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Johnson, James Anthony, Thesis advisor (ths): Aherne, Julian, Degree committee member (dgc): Watmough, Shaun A, Degree committee member (dgc): Huber, Christian, Degree committee member (dgc): Cummins, Thomas, Degree granting institution (dgg): Trent University Abstract: <p>The objective of this thesis was to assess the influence of anthropogenic sulphur (S) and nitrogen (N) deposition, and harvesting on soil acidity and calcium (Ca<super>2+</super>), magnesium (Mg<super>2+</super>), potassium (K<super>+</super>) and N soil pools in plantation forest soils in Ireland. The response to reductions in anthropogenic S… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Catchment soil acidification has been suggested as a possible mechanism for reducing phosphorus (P) loading to surface waters in North America and northern Europe, but much of the research that has been conducted regarding P immobilization in pH manipulated soils has been performed at high P concentrations (> 130 μM). This study investigated how soil acidity was related to P… more Year: 2013, 2013
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Winter nutrient export from forested catchments is extremely variable from year-to-year and across the landscape of south-central Ontario. Understanding the controls on this variability is critical, as what happens during the winter sets up the timing and nature of the spring snowmelt, the major period of export for water and nutrients from seasonally snow-covered forests. Furthermore,… more
