A5083091438- Soil and Water Nutrient Dynamics
- Heavy metals in environment
- Peatlands and Wetlands Ecology
- Lichen and fungal ecology
- Soil Carbon and Nitrogen Dynamics
- Mine drainage and remediation techniques
- Hydrology and Watershed Management Studies
- Forest ecology and management
- Tree-ring climate responses
- Coastal wetland ecosystem dynamics
- Plant responses to elevated CO2
- Seedling growth and survival studies
- Groundwater and Isotope Geochemistry
- Marine and coastal ecosystems
- Atmospheric and Environmental Gas Dynamics
- Coal and Its By-products
- Botany and Plant Ecology Studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Soil and Unsaturated Flow
- Fish Ecology and Management Studies
- Aquatic Invertebrate Ecology and Behavior
- Forest Ecology and Biodiversity Studies
- Plant Water Relations and Carbon Dynamics
- Integrated Water Resources Management
- Geochemistry and Elemental Analysis
Trent University
2015-2024
Syracuse University
2010
University of Virginia
2010
Lund University
2010
University of Novi Sad
2009
Ministry of the Environment, Conservation and Parks
2009
Ministry of Environment
2009
Liverpool John Moores University
1992-1996
We summarize past examples of the use science to document effectiveness policy in air quality management. Our goal is inform public discourse amidst attempts negate relevance and value scientific data fact-based analysis favor partisan opinion ideology. Although fundamental environmental human health, pollution has degraded natural systems reduced economic cultural benefits services. The fresh water across much United States vastly improved recent decades response Clean Air Water Acts other...
Liming and wood-ash addition have long been used to attenuate the effects of acidic deposition on forest soils with goal promoting tree growth. We performed quantitative meta-analyses treatment studies from managed ecosystems assess general tendencies seven selected measures performance thought reasonably reflect Ca-addition treatment. retrieved over 350 independent trials 110 peer-reviewed liming that were integrated determine soil pH, base saturation (BS), foliar Ca concentration, growth,...
Dissolved organic carbon (DOC) fluxes at eight headwater basins in south-central Ontario were strongly related to seasonal streamflow, and extreme events contributed both interannual intercatchment variability. Six catchments with high stream DOC greater peatland coverage exhibited a different pattern of concentration compared two low less wetland influence. In wetland-dominated catchments, concentrations decreased during fall wet-up spring melt, because the dominance melt period annual...
Total phosphorus (TP) levels in many Canadian Shield lakes central Ontario have declined over recent decades, despite increases human activity most watersheds. To investigate the contribution of changes catchment export to long-term declines lake TP, we examined temporal and spatial patterns TP concentrations (1980–1981 2001–2002) across 11 subcatchments that drain into three which average ice-free by approximately 35%. Annual stream decreased significantly 30%–89% eight subcatchments,...
Atmospheric deposition of nitrogen (N) influences forest demographics and carbon (C) uptake through multiple mechanisms that vary among tree species. Prior studies have estimated the effects atmospheric N on temperate forests by leveraging inventory measurements across regional gradients in deposition. However, United States (U.S.), these previous were limited number species spatial scale analysis, did not include sulfur (S) as a potential covariate. Here, we present comprehensive analysis...
In response to large reductions in sulphur (S) emissions over the past 30 years, sulphate (SO42−) concentrations precipitation at Plastic Lake south-central Ontario, Canada, have declined by more than 70%. More recent decreases NOx similarly led a reduction nitrate deposition (NO3−) and consequently pH of bulk has increased approximately 0.8 units since 1980. Despite decrease acidic deposition, chemical recovery streams, as measured an increase aluminum (Al), been much less expected,...
Dendrochemical techniques have been used to monitor historical changes in soil and atmospheric chemistry since the early 1970s. The development of dendrochemistry environmental monitoring was prompted by studies which reported that Pb deposition along roadsides industrial areas were reflected content tree rings. Early inconclusive; some authors stated tree-ring is not a useful indicator pollution episodes species are clearly better spatial indicators than monitors. This due number...
Increased nitrate (NO3) concentrations in streamwaters draining forested catchments are reportedly an early indicator of nitrogen (N) saturation. Nitrate streams 16 south central Ontario were monitored over a 16-year period, during which time N bulk deposition was relatively constant (∼9 kg ha-1 yr-1). Mean annual NO3 both highly variable among and years, although patterns concentration similar many catchments. Coherence analysis identified two stream groupings. Shallow soils, moderate...
Abstract Rising dissolved organic carbon (DOC) concentrations observed at a number of sites in the northern hemisphere over recent decades are subject much debate, and reports suggest link between DOC patterns surface waters changes sulphate (SO 4 ) related to droughts or deposition. In order investigate potential influence SO concentration on south‐central Ontario, we used long‐term (1980–2001) stream monitoring data from wetland‐dominated catchment (Plastic Lake‐1 subcatchment, PC1) that...
Calcium (Ca) concentrations in surface waters on the Precambrian Shield are determined primarily by Ca weathering rate soil, which requires extensive soil data that generally do not exist. From a water chemistry database comprising approximately 550 lakes south-central Ontario, Canada, 130 were selected with low (Ca < 75 µmol·L –1 ). is dominated silicate minerals such as plagioclase and hornblende, allowing use of Ca–sodium (Na) ratios lake to estimate rates. Soil profile at seven sites...
The Athabasca Oil Sands Region of northern Alberta is home to the largest source S emissions in Canada, and some surrounding upland forests are located on acid-sensitive soils. relative sensitivity these ecosystems acidic deposition largely dependent upon mineral weathering rate. Weathering rates were evaluated across a range soils (n = 43) typical region using soil texture approximation (STA) PROFILE model. STA was recalibrated for use region, calculated with this method used calculate...
Peatlands account for 15 to 30% of the world’s soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C N concentrations known vary among peatlands contributing uncertainty inventories, but there few studies that relate peatland classification peat chemistry. We analyzed 436 cores sampled in 24 countries across six continents measured C, N, organic matter (OM) content at three depths down 70 cm. Sites were distinguished between northern (387) tropical (49)...