A5000010237- Marine and coastal ecosystems
- Atmospheric and Environmental Gas Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Soil and Water Nutrient Dynamics
- Fish Ecology and Management Studies
- Methane Hydrates and Related Phenomena
- Microbial Community Ecology and Physiology
- Hydrology and Watershed Management Studies
- Geology and Paleoclimatology Research
- Fire effects on ecosystems
- Ocean Acidification Effects and Responses
- Hydrocarbon exploration and reservoir analysis
- Isotope Analysis in Ecology
- Peatlands and Wetlands Ecology
- Aquatic Invertebrate Ecology and Behavior
- Freshwater macroinvertebrate diversity and ecology
- Oceanographic and Atmospheric Processes
- Soil erosion and sediment transport
- Water Quality Monitoring and Analysis
- Groundwater and Isotope Geochemistry
- Water Quality and Pollution Assessment
- Marine Biology and Ecology Research
- Coastal wetland ecosystem dynamics
- Diatoms and Algae Research
- Climate change and permafrost
Université du Québec à Montréal
2015-2024
GDG Environnement
2019
Pacific Biosciences (United States)
2014
University of Hawaiʻi at Mānoa
2014
University of Hawaii System
2014
Laboratoire d’Océanographie de Villefranche
2014
Ecologie Microbienne Lyon
2014
Sorbonne Université
2014
Laboratoire de Biologie du Développement de Villefranche-sur-Mer
2014
Association for the Sciences of Limnology and Oceanography
2014
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...
One of the major impediments to integration lentic ecosystems into global environmental analyses has been fragmentary data on extent and size distribution lakes, ponds, impoundments. We use new sources, enhanced spatial resolution, analytical approaches provide estimates abundance surface-water bodies. A model based Pareto shows that natural lakes is twice as large previously known (304 million lakes; 4.2 km2 in area) dominated area by millions water bodies smaller than 1 km2. Similar...
We estimated organic carbon (OC) burial over the past century in 40 impoundments one of most intensively agricultural regions world. The volume sediment deposited per unit time varied as a function lake and watershed size, but smaller had greater deposition accumulation rates area. Annual water storage losses from 0.1–20% were negatively correlated with impoundment size. Estimated OC content was greatest lakes low ratios to Sediment higher than those assumed for fertile by previous studies...
Dissolved organic carbon (DOC) is a key parameter in lakes that can affect numerous features, including microbial metabolism, light climate, acidity, and primary production. In an attempt to understand the factors regulate DOC lakes, we assembled large database (7,514 from 6 continents) of concentrations other parameters characterize conditions catchment, soil, climate. were range 0.1–332 mg L −1 , median was 5.71 . A partial least squares regression explained 48% variability lake showed...
Dissolved organic matter (DOM) is a master variable in aquatic systems. Modern fluorescence techniques couple measurements of excitation emission matrix (EEM) spectra and parallel factor analysis (PARAFAC) to determine fluorescent DOM (FDOM) components quality. However, the molecular signatures associated with PARAFAC are poorly defined. In current study we characterized river water samples from boreal Québec, Canada, using EEM/PARAFAC ultrahigh resolution mass spectrometry (FTICR-MS)....
Abstract Methane (CH 4 ) emissions from aquatic systems should be coupled to CH production, and thus a temperature‐dependent process, yet recent evidence suggests that modeling may more complex due the biotic abiotic processes influencing emissions. We studied magnitude regulation of two pathways—ebullition diffusion—from 10 shallow ponds 3 lakes in Québec. Ebullitive fluxes averaged 4.6 ± 4.1 mmol m −2 d −1 , contributing ∼56% total (diffusive + ebullitive) In lakes, ebullition only...
We performed a series of gas exchange measurements in 12 diverse aquatic systems to develop the direct relationship between near‐surface turbulence and transfer velocity. The was log‐linear, explained 78% variation instantaneous velocities, valid over range turbulent energy dissipation rates spanning about two orders magnitude. Unlike wind‐based relationships, our model is applicable ranging size from less than 1 km 2 600 . Gas fluxes measured with specific floating chambers can be grossly...
Scientific Significance Statement This essay describes the evolution of our understanding carbon cycle inland waters. Research has evolved from studies individual lakes with limited attention to surrounding landscapes, a focus on how are affected by external factors such as import organic matter watershed, thereafter increasingly addressing waters impact beyond their own limits, for example emission gases atmosphere. Major steps described toward now widely applied concept aquatic "active...
We have developed a protocol for the cytometric enumeration of bacterioplankton in lakes with nucleic acid stain SYTO 13; our can be used any standard bench‐top flow cytometer equipped an argon laser excitation at 488 nm. The performs well range bacterial densities from 10 5 to 6 ml −1 . Estimates abundance using technique ranged 72 141% epifluorescence estimates DAPI staining. average C.V. replicate counts was 2.4%, and water samples 6.7%. precision 10‐fold higher than corresponding counts,...
We investigated bacterial responses to variations in dissolved organic carbon (DOC) and nutrient availability by a comparative analysis of metabolism lakes ranging from oligotrophic eutrophic. Bacterial growth, respiration, growth efficiency were quantified lake water dilution cultures performed 20 located eastern Quebec, Canada, which varied with respect both DOC concentrations. Intrinsic rates the bacteria ranged 0.1 1.4 d − , cell‐specific respiration 0.4 7.2 fg C cell −1 h efficiencies...
On the basis of data collected in Quebec lakes, del Giorgio and Peters (1994) Carignan et al. (2000) have come to opposite conclusions regarding metabolic balance between heterotrophy autotrophy lakes general. In present study, epilimnetic oxygen carbon dioxide saturation was measured 33 from St. Lawrence Lowlands region examine extent net (i.e., O 2 :CO balance) different characteristics. We found that ~75% were undersaturated with supersaturated CO . There a strong negative relationship...
Air–water diffusive gas flux is commonly determined using measurements of concentrations and an estimate transfer velocity (k 600 ) usually derived from wind speed. The great heterogeneity aquatic systems raises questions about the appropriateness a single wind-based model to predict k in all systems. Theoretical considerations suggest that speed relationships should instead be system-specific. Using data collected different sizes, we show related fetch other measures ecosystem size. Lake...
We used data drawn from the literature to test some basic predictions derived nutrient limitation theory. Contrary expectation, nitrogen was not better correlated chlorophyll in limited lakes (as measured by total nitrogen:total phosphorus (TN:TP) ratio). also examined whether variability published relationships between a (Chla) and levels can be explained differences relative concentrations of (TN:TP Our results show that coefficients precision Chla = f(TP) f(TN) regression equations vary...
The role of saline lakes in CO 2 exchange with the atmosphere was evaluated on basis calculated partial pressure ( p ) and rates derived from a compilation published data for 196 around world. average surface water exceeded atmospheric by factor 5–8 times, indicative tendency to emit atmosphere. Chemically enhanced emission, solute chemistry, pH, wind speed, increased gas an 2.3 times over that freshwater having equivalent . globally distributed emitted at excess 80 mmol m −2 d −1 Caspian...
Here we examine the patterns in carbon dioxide partial pressure ( p CO 2 ) measured a number of small boreal streams (<5 km length) northwestern region Québec during ice‐free season and compare these to found major river (Eastmain River) tributary same region. All systems were consistently supersaturated (range 450 5000 μ atm) having both higher (mean 1850 more variable than that rivers 550 800 atm). Stream was positively related DOC concentration stream segment length, suggesting direct...
The color of freshwaters, often measured as absorbance, influences a number ecosystem services including biodiversity, fish production, and drinking water quality. Many countries have recently reported on increasing trends in for which drivers are still not fully understood. We show here with more than 58000 samples from the boreal hemiboreal region Sweden Canada that absorbance filtered (a420) co-varied dissolved organic carbon (DOC) concentrations (R2 = 0.85, P<0.0001), but a420 relative...
In this perspective article, I argue that dissolved organic carbon occupies a central role in the functioning of lake ecosystems, comparable importance to played by nutrients. Because lakes receive so much from terrestrial landscape, its accumulation water bodies usually represents largest pool lacustrine matter within column. The transformation even small fraction external microbial community can alter significantly metabolic balance simultaneously releasing dioxide atmosphere and burying...