Northern environments have been subject to constant change throughout the last few thousand years, but the pace of change appears to have accelerated markedly over the last century. The aim of this theme is to determine the rate of change at different spatio-temporal scales, to evaluate the magnitude of present changes relative to the past, and to understand the consequences for northern land and coastal geo-ecosystem function. These studies focus on critical thresholds, feedback mechanisms at the ecosystem level, and on the effects of global warming. The research aims to identify the mechanisms by which these changes act on various geo-ecosystem variables, and to anticipate the magnitude and direction of change by understanding the causal processes and consequences.
This research area includes five themes.
Researchers: Florent Dominé, Gilles Gauthier; Michel Allard, Marc Amyot, Dominique Arseneault, Marcel Babin, Simon Bélanger, Pascal Bernatchez, Dominique Berteaux, Joël Bety, Najat Bhiry, Stéphane Boudreau, Étienne Boucher, Steeve Côté, France Dufresne, Marco Festa-Bianchet, Pierre Francus, Michelle Garneau, Bernard Hétu, Alexandre Langlois, Isabelle Laurion, Claude Lavoie, Martin Lavoie, Jean-Philippe Lessard, Esther Lévesque, Connie Lovejoy, Guillaume Marie, Serge Payette, Reinhard Pienitz, Milla Rautio, Line Rochefort, Nigel Roulet, Alain Royer, Martin Simard, Martin-Hugues St-Laurent, Jean-Pierre Tremblay, François Vézina, Warwick F. Vincent, Rosa Galvez, Nicolas Lecomte, Oliver Sonnentag, Christophe Kinnard.
Models predicting the current and anticipated impacts of climate change on geo-ecosystem dynamics must be supplied by paleo-environmental reconstitutions derived from a variety of archives. These supply critical information on climate forcings and geo-ecosystem dynamics through time. We are carrying out long historical reconstitutions with fine temporal and stratigraphic resolutions to understand natural climate variation and better define the processes which shaped the changing environmental conditions during the Quaternary Period. The analysis of geo and bio-indicator databases (magnetic susceptibility, granulometry, geochemistry, diatoms, pollen, invertebrates, pigments, etc.) is undertaken to better define the transformation patterns of Northern Canadian landscapes to reconstitute the history of environmental change and to comprehend the evolutionary change in key species. The development of paleo-ecological reference points and historical environmental data help to define target zones for ecological restoration and to elaborate monitoring and conservation programs.
Researchers: Reinhard Pienitz; Michel Allard, Dermot Antoniades, Dominique Arseneault, Pascal Bernatchez, Najat Bhiry, Étienne Boucher, France Dufresne, Pierre Francus, Bernard Hétu, Claude Lavoie, Martin Lavoie, Milla Rautio, Line Rochefort, Nigel Roulet, Martin Simard, Warwick F. Vincent.
This theme examines the impacts of climate change on the physical characteristics of northern aquatic environments (ice cover, stratification, thermal regime) and their implications on biogeochemistry, contaminant dynamics, plant and microbial biodiversity and biological productivity. Climate change affects river flow and expands aquatic thermokarst ecosystems associated with thawing permafrost and the acceleration of the hydrological cycle. These aquatic ecosystem types release more gaseous carbon into the atmosphere than permafrost, thus contributing to climate change-inducing mechanisms. On the other hand, carbon is sequestered in some thermokarst ponds. The main objective of this theme is to decipher the biogeochemistry, hydrology, and ecology of aquatic environments as well as our knowledge of their links with the terrestrial environment. The complexity of these important systems requires the development of optical, paleo-climatic, limnological, and molecular tools to estimate the emission of greenhouse gases as well as their transformation and responses to actual and future changes. We are contributing to the quantification of climate feedback and improving our ability to better predict the northern climate.
Researchers: Isabelle Laurion; Michel Allard, Marc Amyot, Dermot Antoniades, Marcel Babin, Najat Bhiry, Karem Chokmani, Florent Domine, Pierre Francus, Michelle Garneau, Connie Lovejoy, Taha M.J. Ouarda, Reinhard Pienitz, Milla Rautio, Nigel Roulet, Martin-Hugues St-Laurent, Warwick F. Vincent, Rosa Galvez, Oliver Sonnentag, Christophe Kinnard.
Modeling the exchanges between the atmosphere, vegetation and permafrost using high spatial resolution (ex. cells of 40 x 40 km) requires parameters measured in the field and algorithms that reproduce the interactions between these three components of the environment. For example, the impact of vegetation growth on the physical properties of snow and thermal patterns of the permafrost is not yet represented in any models. The necessary parameterizations must be developed, based on observations, measurements and monitoring in the field from, amongst other things, our network of SILA-Qaujisarvik stations where the number of measured variables is increasing constantly. This data allows the quantification and formalization of the exchanges of energy and matter between the various environmental components in order to include them in the modeling and better predict the impacts on northern environments and infrastructures. A projection with advanced and accurate technology infers setting up a data bank of georeferenced data listing thermal parameters of geological surfaces and of plant, snow and ice cover necessary for the calculations. The data collected is available to the international community via Nordicana D.
Researchers: Dominique Arseneault; Esther Lévesque, Michel Allard, Pascal Bernatchez, Monique Bernier, Dominique Berteaux, Florent Domine, Richard Fortier, Pierre Francus, Gilles Gauthier, Alexandre Langlois, Isabelle Laurion, Reinhard Pienitz, Alain Royer, Nigel Roulet, Diane Saint-Laurent, René Therrien, Warwick F. Vincent, Oliver Sonnentag, Christophe Kinnard.
Climate change will affect the biocenosis of northern ecosystems, however, the response of the organisms will vary at all levels, from the individual to the ecosystem level. These varying responses could disrupt spatial and temporal synchronization between trophic levels, thereby affecting biodiversity. These phenomena are amplified in northern regions where the species diversity is low, thereby increasing the influence of a single species on ecosystem dynamics as a whole, and where species migrate great distances. This theme examines these dynamics for the key boreal forest and tundra herbivore species, including ungulates, geese, and lemmings across a 3000 km latitudinal gradient. Long term monitoring of these populations, their feeding habits and the predator-prey interactions are coupled with in situ experiments (artificial warming, variations in snow cover) and experiments in controlled environments (acclimation to varying temperatures) to evaluate the sensitivity of northern food webs to disturbances and to model the effects of these disturbances. In addition, field studies coupled with satellite-telemetry data allow us to evaluate the actual and future state of various animal populations.
Researchers: Steeve Côté; Dominique Berteaux, Joël Bêty, Marco Festa-Bianchet, Gilles Gauthier, Jean-Philippe Lessard, Esther Lévesque, Serge Payette, Fanie Pelletier, Line Rochefort, Martin-Hugues St-Laurent, Jean-Pierre Tremblay, François Vézina, Nicolas Lecomte.
In the dual context of climate warming and socio-economic change, water resources in the North are often difficult to access and are vulnerable to contamination. The cold temperatures make their exploitation complex as local communities depend on surface waters as their main source of drinking water and these freeze over the winter months, causing water shortages in the communities. In the context of permafrost thaw, the exploitation of underground water may become an alternative option since the water freed by permafrost thaw and the melting of land ice and snow could replenish aquifers and further increase groundwater supplies. In-depth knowledge of the water cycle in northern environments allows a better understanding of the feedback loop existing between climate warming, permafrost degradation, and geosystem dynamics. The evolution of the depth of the active layer is analyzed using satellite imagery coupled with field data. This allows us to closely monitor surface-layer temperatures as well as evaluate snow cover and its influence on the Earth’s energy balance. In the boreal zone, we also analyze the short and long term variability of the water supply in hydroelectric dams and natural systems.
Researchers: Richard Fortier; Michel Allard, Dermot Antoniades, Dominique Arseneault, Thomas Buffin-Bélanger, Simon Bélanger, Pierre Francus, Alexandre Langlois, Isabelle Laurion, Martin Lavoie, Jean-Michel Lemieux, Dominic Larivière, John Molson, Reinhard Pienitz, Milla Rautio, Alain Royer, Nigel Roulet, Martin Simard, René Therrien, Warwick F. Vincent, Rosa Galvez, Christophe Kinnard.