A5103107691- Soil and Water Nutrient Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Fish Ecology and Management Studies
- Marine and coastal ecosystems
- Hydrology and Watershed Management Studies
- Groundwater and Isotope Geochemistry
- Peatlands and Wetlands Ecology
- Aquatic Invertebrate Ecology and Behavior
- Water Quality and Pollution Assessment
- Heavy metals in environment
- Freshwater macroinvertebrate diversity and ecology
- Mine drainage and remediation techniques
- Environmental Toxicology and Ecotoxicology
- Mercury impact and mitigation studies
- Isotope Analysis in Ecology
- Diatoms and Algae Research
- Atmospheric chemistry and aerosols
- Water Quality and Resources Studies
- Geology and Paleoclimatology Research
- Soil Carbon and Nitrogen Dynamics
- Ecology and biodiversity studies
- Integrated Water Resources Management
- Invertebrate Taxonomy and Ecology
- Soil erosion and sediment transport
- Geochemistry and Geologic Mapping
Trent University
2009-2023
Hutchinson (Canada)
2023
University of Saskatchewan
2023
University of Waterloo
1990-2023
Rush University Medical Center
1987-2011
Ministry of the Environment, Conservation and Parks
1992-2009
Ministry of Environment
1993-2009
CSIRO Land and Water
2000-2004
Swedish University of Agricultural Sciences
2004
Ministry of Environment, Forests and Climate Change
1997-1999
We explore the role of lakes in carbon cycling and global climate, examine mechanisms influencing pools transformations lakes, discuss how metabolism inland waters is likely to change response climate. Furthermore, we project changes as climate abundance spatial distribution biosphere, revise estimate for extent transformation waters. This synthesis demonstrates that annual emissions dioxide from atmosphere are similar magnitude uptake by oceans burial organic water sediments exceeds...
Data for summer chlorophyll and spring total phosphorus concentration were collected from 19 lakes in southern Ontario combined with data reported the literature other North American to produce a regression line that can be used predict average single measurement of at overturn. This equation is not significantly different previously published phosphorus‐chlorophyll relationship derived number Japanese lakes.
The region studied includes the Laurentian Great Lakes and a diversity of smaller glacial lakes, streams wetlands south permanent permafrost towards southern extent Wisconsin glaciation. We emphasize lakes quantitative implications. is warmer wetter than it has been over most last 12000 years. Since 1911 observed air temperatures have increased by about 0·11°C per decade in spring 0·06°C winter; annual precipitation 2·1% decade. Ice thaw phenologies since 1850s indicate late winter warming...
The total phosphorus budgets for a number of lakes in the Haliburton–Kawartha region southern Ontario were measured over 20-mo period. These data, combined with lakes' morphometry and water budgets, used to test simple nutrient budget model similar that proposed by Vollenweider (1969) purporting predict concentration lakes. Except case two very shallow [Formula: see text], concentrations predicted close those at spring overturn. Additional data from literature supported belief this could be...
Predicting the effects of climate change and atmospheric deposition on water quality requires predicting landscape form export substances downstream. In this paper, we present dissolved organic carbon (DOC), total phosphorus (TP), iron (Fe) data (1980–1992) for 20 relatively undisturbed, forested catchments draining into seven lakes in central Ontario develop regression models chemical as functions composition. The extent wetlands was correlated with DOC TP; proportion catchment covered by...
A general technique is presented for calculating the capacity of a lake development based on quantifiable relationships between nutrient inputs and water quality parameters reflecting trophic status. Use southern Ontario lakes described. From land use geological formations prevalent in lake’s drainage basin, phosphorus exported to runoff can be calculated, which, when combined with input directly surface precipitation dry fallout, gives measure natural total load. population around lake,...
We present a new, process‐based model of soil and stream water dissolved organic carbon (DOC): the Integrated Catchments Model for Carbon (INCA‐C). INCA‐C is first DOC cycling to explicitly include effects different land cover types, hydrological flow paths, in‐soil biogeochemistry, surface processes on in‐stream concentrations. It can be calibrated using only routinely available monitoring data. simulates daily concentrations over period years decades. Sources, sinks, transformation solid...
The relationship between phosphorus retention and several other lake watershed parameters was examined for 15 lakes. A model relating the areal water load ( q s ) to proposed: R p = 0.426 exp (−0.271 + 0.574 (−0.00949 ). This found be theoretically sound, predicted measured values were in close agreement r 0.94).
The total phosphorus budget of Cameron Lake is described for two 12‐month periods. Although the loadings were high (1.70 and 2.21 g m −2 yr −1 ), lake not cutrophic because a flushing rate counteracts loading. A plot L(1–R)/ ρ, where L loading, R retention coefficient in lake, ρ hydraulic rate, vs. (z), mean depth, suggested as means relating trophic state to This formulation accurately predicted that nearby Four Mile would be almost identical terms degree cutrophy despite fact Lake’s load...
Abstract There is considerable variation in published phosphorus‐chlorophyll relationships, some of which can be accounted for by sampling and analytical techniques. As well, there significant inherent variability a single relationship under even ideal conditions. A survey the literature shows that cellular chlorophyll content algae ranges over two orders magnitude (0.1—9.7% fresh weight). Average daily radiation intensity nutrient availability (especially N) appear to major factors...
Dissolved organic carbon (DOC) is important in the acid‐base chemistry of acid‐sensitive freshwater systems; complexation, mobility, persistence, and toxicity metals other pollutants; lake metabolism. Carbon isotopes ( 13 C 14 C) are used to study origin, transport, fate DOC a softwater catchment central Ontario. Precipitation, soil percolates, groundwaters, stream, beaver pond, waters, sediment pore water were characterized chemically isotopically. In addition total DOC, isotopic...
The literature pertaining to the influence of atmospheric deposition acidifying substances on aquatic ecosystems is examined in this article. Important chemical species are first identified, and their stream ultimately lake water chemistry discussed. Changes that have accompanied acidification among biological communities decomposers, primary higher order producers Where they exist, hypotheses relating causes community changes examined.
[1] Nitrous oxide (N2O) is a potent greenhouse gas produced during nitrogen cycling. Global enrichment has resulted in increased atmospheric N2O concentrations due large part to soil emissions. There also potentially important flux from streams, rivers and estuaries; although measurements of these emissions are sparse, role aquatic ecosystems global budgets remains highly uncertain. Using the longest-term fluxes streams date, we found annual 14 sites five south-central Ontario, Canada varied...
1. Within a lake district of relatively homogeneous geomorphology, the responses lakes to climate are influenced by complexity hydrogeologic setting, position in landscape, and lake‐specific biological physical features. We examined chemical drought surface water‐ groundwater‐dominated districts address two general questions. (1) Are spatial patterns dynamics among uniform synchronous within district, suggesting broad geomorphic controls; variable spatially explicit pattern, with synchrony...
Annual catchment export of total phosphorus (TP), dissolved organic carbon (DOC), iron (Fe), and nitrogen (DON) to seven lakes in central Ontario was measured between 1978 1998. Fluctuations annual water discharge DOC load (including precipitation) the over 20‐year period were similar study lakes. responded proportionally changes discharge, decreasing during drier warmer years. There but less accentuated variations lake concentrations. no clear regional trends evident toward or wetter...