A5011594053- Freshwater macroinvertebrate diversity and ecology
- Fish Ecology and Management Studies
- Aquatic Invertebrate Ecology and Behavior
- Soil and Water Nutrient Dynamics
- Hydrology and Watershed Management Studies
- Hydrology and Sediment Transport Processes
- Marine Biology and Ecology Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Species Distribution and Climate Change
- Wastewater Treatment and Nitrogen Removal
- Invertebrate Taxonomy and Ecology
- Isotope Analysis in Ecology
- Environmental DNA in Biodiversity Studies
- Lepidoptera: Biology and Taxonomy
- Microbial Community Ecology and Physiology
- Water Quality and Pollution Assessment
- Environmental Conservation and Management
- Urban Stormwater Management Solutions
- Marine and fisheries research
- Indigenous Studies and Ecology
- Land Use and Ecosystem Services
- Diptera species taxonomy and behavior
- Environmental Toxicology and Ecotoxicology
- Ecology and Vegetation Dynamics Studies
- Ecology and biodiversity studies
University of Windsor
2019-2024
Great Lakes Institute of Management
2024
Great Lakes Institute for Environmental Research
2020-2023
University of Canterbury
2015-2022
The Scarborough Hospital
2006-2021
University of Toronto
2008-2021
Christ University
2017
Colorado State University
2016
University of Maryland Center for Environmental Science
2011-2015
University of Maryland, College Park
2012-2015
Temporary fresh waters are defined as bodies of water that experience a recurrent dry phase varying length is sometimes predictable in both its time onset and duration. The aquatic insects live these habitats strongly influenced by 2 main groups constraints, physicochemical biological factors. Taxa particularly well-represented temporary running the Ephemeroptera, Hemiptera, Coleoptera, Trichoptera, tipulid chironomid Diptera. With exception all common also lentic waters, but latter support...
Summary The vertical distribution of the benthic fauna Speed River, Ontario, was studied over a 13‐month period from October 1970 to 1971. Various physical and chemical parameters this interstitial environment were also measured. Several new techniques for sampling rivers wert devised. These methods their relative efficiencies are considered. validity terms ‘hyporheal’ ‘hyporheic’ discussed term ‘hyporheos’ is offered replace former. A brief resume given with comments on limitations deep...
The animals recolonizing an area of denuded stream substrate are thought to come from four main sources. These drift, upstream migration within the water, substrate, and aerial sources, e.g., oviposition. An experiment in a Canadian showed drift be most important source animals, contributing 41.4% total number that settled on 1800 cm2. This compares with 28.2% sources while movement up contributed about equally (18.20% 19.1 00, respectively). Clearly then, all directions repopulating bare...
Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoint source urban inputs on quantity, quality, ultimate fate dissolved organic matter (DOM) is poorly understood. We assessed DOM quality microbial bioavailability in eight first-order Coastal Plain headwater streams along a gradient (i.e., percent watershed impervious cover); none had point discharges. was measured using fluorescence excitation-emission matrices (EEMs) coupled with parallel factor...
Subsurface flow within a single riffle of low‐gradient gravel bed stream was modeled in three dimensions using MODFLOW, finite difference groundwater model. Model simulations showed that exchange flows can only occur this low‐gradient, gaining because zone alluvial sediment around the has much higher permeability than surrounding catchment ( K = 10 −4 m s −1 , compared with −6 to −8 ). The key factors controlling were identified as hydraulic conductivity alluvium, gradient between upstream...
We manipulated, in accord with global—warming predictions, the thermal regime of a permanent first—order stream near Toronto, Ontario, Canada. examined effects 2—3.5 ° C water—temperature increase on densities, biomass, species composition, and life histories resident invertebrates. The was divided longitudinally at source into two channels, one control experimental, before after (BACI) design employed such that pre—manipulation year followed by 2 yr temperature manipulation. Changes...
1. Temporary waters are bodies of water that experience a recurrent dry phase varying length is sometimes predictable in its onset and duration. The maximum number temporary permanent ponds England Wales 1880 estimated to be >1 million. A 1920s survey showed lowest densities mountainous areas (0.12 km−2) highest ancient woodland agriculture (115 km−2). 2. most important physical chemical influences on the biota aquatic phase, pattern disappearance water, whether latter or unpredictable....
Urbanization strongly influences headwater stream chemistry and hydrology, but little is known about how these conditions impact bacterial community composition. We predicted that urbanization would composition, water column communities be most linked to at a watershed-scale, as measured by impervious cover, while sediment correlate with environmental the scale of reaches. To test this hypothesis, we determined composition in streams located across gradient watershed cover using...
Abstract Climate change and human pressures are changing the global distribution extent of intermittent rivers ephemeral streams (IRES), which comprise half river network area. IRES characterized by periods flow cessation, during channel substrates accumulate undergo physico‐chemical changes (preconditioning), resumption, when these rewetted release pulses dissolved nutrients organic matter (OM). However, there no estimates amounts quality leached substances, nor is information on underlying...
A series of time—specific food webs for the macroinvertebrate riffle community Duffin Creek, Ontario was constructed using dietary information obtained from analysis gut contents. Trophic links were quantified a index relative importance. Precision maintained at high level by: (1) identifying items as accurately possible via direct analysis; (2) web members to species level, thus avoiding taxonomic aggregation and lumping size classes common in analyses; (3) ensuring temporal resolution by...
Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Although randomization in the collection units often used assure that sampling representative, does not convey concept how well samples represent community site from which they are drawn. In surveys, represents literally means similarity composition and relative abundance between it Using both field simulated data, we show...
On examine, au laboratoire, les interactions (sans contact) de G. p. avec des individus sa propre espece et predateurs ou non-predateurs vivant sein la biocenose cours d'eau dans lesquels il vit, le sud l'Ontario
Food webs depict who eats whom in communities. Ecologists have examined statistical metrics and other properties of food webs, but mainly due to the uneven quality data, results proved controversial. The qualitative data on which those efforts rested treat trophic interactions as present or absent disregard potentially huge variation their magnitude, an approach similar analyzing traffic without differentiating between highways side roads. More appropriate are now available were used here...
When exposed to increases in current speed a laboratory stream tank, crayfish altered their body posture counteract the effects of drag, thus enabling them maintain station at higher speeds. Using beam-type drag balance, direct measurements were made on live adults eight Ontario species over range The then ranked according relative streamlining efficiencies as indexed by these measurement data. station-holding abilities compared determining mean slip each roughened Plexiglas substrate. There...
SUMMARY. 1. A series of samples interstitial water and fauna was taken along transects from the channel into bank in two small rivers southern Ontario, Canada. These were examined for any discontinuities which might indicate position hyporheic/groundwater interface. 2. There several chemical Duffin Greek, with “break lines” occurring about river margin obliquely downwards under dissolved oxygen carbon dioxide, B.O.D., alkalinity, suspended solids amount organic matter. Break lines nitrate...
Summary 1. The hyporheic zone of a permanent first‐order stream was divided into treatment and control section using 1 m deep sheet‐metal barrier. During 4‐month pre‐treatment period, water temperatures in two transects the sections were not different. Upon heating, temperature transect increased by an average 4.3 °C over values transect. 2. Eleven bimonthly core samples taken from transect, recovered CPOM classified as twigs, wood, grass, roots, cedar deciduous leaves. 3. In both transects,...
Baskets filled with stones, to give four different degrees of heterogeneity, were placed in a stream and made available for colonization by benthic invertebrates. No difference resulted the total numbers weights animals colonizing; 26% species, however, showed clear substrate preferences, 35% slight 39% none. The last group up most invertebrate biomass. A high quantity detritus accumulated each substrate, this may account similar densities detritivores collected on all substrates.