Grant: Research Tools and Instruments

This proposal aims to equip three professors (Guillemette: aquatic microbiology; Maire: Soil-plant interaction; Roy: Land-Atmosphere exchanges modelling) with a state of the art ultraportable nitrous oxide (N2O) gas analyzer that will complete a carbon dioxide-methane (CO2, CH4) gas analyzer already owned by the team, developing a Portable platfOrm for greenhouse Gas measurements along the wAtershed-aquatic ecoSystem continuum hereafter referred to as POGAS. Our complementary research programs will together improve the quantification and understanding of the processes related to greenhouse gas emissions (G) during both vegetation period and wintertime in various ecosystems from agriculture-impacted floodplains of the St-Lawrence River followed by the Interuniversity Research Group in Limnology (GRIL), up to tundra wetlands located across the research station network of the Center of Northern Studies (CEN). This will cover a worldwide-unique large latitudinal gradient in North hemisphere from the 46° to the 83° parallel. Agricultural soils are the greatest single source of N2O. As part of the pole d'Expertise multidisciplinaire sur la gestion durable du Lac Saint-Pierre, a large multi-stakeholder project funded by the Quebec government, the largest floodplain and wetland complex along the St-Lawrence River, we monitored CO2 and CH4 fluxes to quantify the impact of landuse, agricultural pratices and flooding intensity on C-N cycling. With the equipment, we aim to get a complete picture of the radiative transfer budget in the floodplain year-round, including winter fluxes through the snowpack. Gas flux data will be combined with microbial community composition data obtained through multimarker eDNA metabarcoding and metagenomic sequencing of floodplain sites, revealing the microbial community responsible of the cycling rate of C and N within ecosystems. Permafrost soils cover roughly 25% of northern hemisphere lands and growing evidence suggests that Arctic soils may be important sources of N2O. Thawing of the perennially frozen ground (permafrost) in a large portion of the vast Arctic region has the potential to release enormous amounts of GHGs to the atmosphere, which is considered one of the strongest potential climate system feedbacks. We will specifically measure how the greening of Arctic through shrubification modulates N cycle and N2O emission during growing seasons. Large uncertainties in the GHG budget remain in winter conditions that encompass more than half the year in arctic tundra and boreal forest. POGAS will be deployed across four sites using a snow diffusion method dedicated to measuring winter GHG fluxes through the snow cover. POGAS will support the training of HQP to new highly valuable techniques and data analysis besides yielding important new insights into how global change impacts the rapidly changing terrestrial and aquatic ecosystems of Eastern Canada, as well as the potential feedbacks to the atmosphere.