Yves T. Prairie

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Because freshwater covers such a small fraction of the Earth’s surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking published estimates of gas exchange, sediment accumulation, and(More)
One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies.(More)
We investigated bacterial responses to variations in dissolved organic carbon (DOC) and nutrient availability by a comparative analysis of bacterial metabolism in lakes ranging from oligotrophic to eutrophic. Bacterial growth, respiration, and growth efficiency were quantified in lake water dilution cultures performed in 20 lakes located in eastern Quebec,(More)
[1] We estimated organic carbon (OC) burial over the past century in 40 impoundments in one of the most intensively agricultural regions of the world. The volume of sediment deposited per unit time varied as a function of lake and watershed size, but smaller impoundments had greater deposition and accumulation rates per unit area. Annual water storage(More)
In natural bacterioplankton assemblages, only a fraction of the total cell count is active, and, therefore, rates of bacterial production should be more strongly correlated to the number of active cells than to the total number of bacteria. However, this hypothesis has seldom been tested. Herein we explore the relationship between rates of bacterial(More)
Recent, parallel developments in the study of freshwater and marine ecosystems have provided evidence that net heterotrophic systems (those in which respiratory organic matter destruction exeeds photosynthetic production) are more prevalent than hitherto believed, including most rivers, oligo- to mesotrophic lakes and some oligotrophic regions of the ocean.(More)
Although often seen as a scale-independent measure, we show that the fractal dimension of the forest cover of the Cazaville Region changes with spatial scale. Sources of variability in the estimation of fractal dimensions are multiple. First, the measured phenomenon does not always show the properties of a pure fractal for all scales, but rather exhibits(More)
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 and DOM quality. However, the molecular signatures associated with PARAFAC components are poorly defined.(More)
Methanogenesis has traditionally been assumed to occur only in anoxic environments, yet there is mounting, albeit indirect, evidence of methane (CH4) production in oxic marine and freshwaters. Here we present the first direct, ecosystem-scale demonstration of methanogenesis in oxic lake waters. This methanogenesis appears to be driven by acetoclastic(More)
It is a common misconception that correlations between variables that share a common term are statistically invalid. Although the idea that such relationships are wholly or partially spurious was rejected decades ago by statisticians, ecologists continue mistakenly to exclude legitimate hypotheses on this basis. Besides directing attention to the(More)