Canada’s GHG reductions and carbon offsets to prevent warming beyond 1.5 °C need to be reported internationally in order to be recognized in global negotiations around climate change. With growing local and national scale interest in wetlands as a Nature-based climate Solution, improved estimates of wetland organic carbon (OC) sequestration and GHG flux across wetland types are required. While significant research has focused on carbon cycling in Canadian peatlands, few studies have investigated ecosystem-scale carbon cycling and GHG dynamics of freshwater mineral wetlands in Canadian agricultural landscapes. The objective of this project is to determine the magnitude and uncertainty in GHG estimates and generate tools to predict GHG reductions through conservation and restoration of wetlands. The investigators develop mechanistic models of wetland carbon cycling to help understand empirical estimates for rates of OC accumulation in wetlands, GHG fluxes from wetlands to the atmosphere, and carbon fluxes to (and from) wetlands. A multitude of biogeochemical processes are considered to determine the fate of carbon, such as gas exchanges at the interface between wetlands and the atmosphere, seasonality of the organic matter decomposition under different redox-potential regimes, photosynthesis and uptake by the autotrophic assemblages, autotrophic and heterotrophic respiration, particle settling, diffusive transport from the sediments, sediment resuspension, and advective mass exchanges within the wetlands. The project uses a recursive approach, whereby available data are used to calibrate the mechanistic models, and then the derived characterization of wetland processes along with the associated uncertainties are used to dictate future data collection efforts or to identify compelling hypotheses that can be tested in the field. The mechanistic models also provide the platform to run a series of “what-if?” scenarios, where we can predict the potential role of wetlands in the local, regional, and global carbon cycling under alternative scenarios (i.e., changes in weather predictions and frequency of extreme events, and changes in land management schemes). The models will be used to generate information related to the importance of wetlands in achieving national GHG reduction targets, and to enable adaptive management.

For more information, please contact Dr. Irena Creed ([email protected]) and Dr. George Arhonditsis ([email protected]).