Detailed regional studies. Over the first four years of the CarBBAS Chair program, we carried out regional studies of greenhouse gas (GHG) dynamics and carbon cycling in lakes, streams, rivers, and wetlands in seven key regions of the boreal and taiga biomes: Abitibi, James Bay, Saguenay, Chibougamau, Schefferville, Labrador and Côte-Nord. Within each region, we performed point sampling of GHG and basic limnological factors in a large number of lakes and rivers, chosen to represent the largest range of aquatic and landscape properties. Other research sub-components, such as studies of carbon storage, seasonal variation, winter metabolism, CO2 dynamics, and carbon consumption, were carried out on a subset of these lakes, rivers, and watersheds, by visiting them on several occasions. Models of GHG dynamics and other aspects of lake function will be developed for each region in order to compare patterns and forcing factors among regions.
Sentinel systems. We selected a sentinel lake in two key boreal regions (Abitibi and Saguenay) as well as in the temperate Laurentian region. These lakes and their associated streams are being followed for the length of the Chair program, allowing us to study temporal (seasonal and inter-annual) dynamics of CO2 and CH4, as well as dissolved organic carbon (DOC) mass balances, carbon burial and export, and the isotopic signature of metabolized carbon. We installed sensors at the outlet of each sentinel lake to automatically measure discharge and establish the annual hydrologic load. An autonomous buoy is installed on each lake to continuously record GHG and DOC dynamics during the ice-free period and the lakes are sampled periodically during the winter. The deployment of autonomous buoys on Lake Croche (Station de biologie des Laurentides de l’Université de Montréal) and Lake Simoncouche (Forêt d'enseignement et de recherche de l’UQAC) allowed us to connect the first two Canadian lakes to the Global Lake Ecological Observatory Network (GLEON).
Process and landscape modeling. We characterized certain aquatic and non-aquatic components of the landscape using remote sensing and GIS analysis, while other components, such as the export of materials in terrestrial runoff and groundwater, were assessed by in situ sampling. We will develop models to describe the configuration of aquatic networks in the landscape, which can be coupled to models of aquatic GHG and carbon dynamics, existing terrestrial carbon models, and regional climate models. We will also develop process models of carbon dynamics in lakes to explore how they would evolve under scenarios of changing carbon inputs and climate.
