NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: greenhouse gases

Objective(s): The goal of this research is to explore the importance of greenhouse gas uptake, particularly methane and nitrous oxide, by arctic soils. We want to investigate both the magnitude of methane and nitrous oxide uptake by soils, and more importantly, identify the major underlying biogeochemical and microbial processes that determine if the ecosystem is a sink or a source of these climate-relevant gases.

Project Description: This licence has been issued for the scientific research application No. 6120. The goal of this research is to explore the importance of greenhouse gas uptake, particularly methane and nitrous oxide, by arctic soils. We want to investigate both the magnitude of methane and nitrous oxide uptake by soils, and more importantly, identify the major underlying biogeochemical and microbial processes that determine if the ecosystem is a sink or a source of these climate-relevant gases. The aim of this project is to investigate the importance of methane and nitrous oxide uptake by arctic soils. Previous sampling in the region has shown that certain soil types and landcover features near Trail Valley Creek have the potential to be a sink for methane in the Arctic. This work will be conducted as part of the ERC Starting Grant COLDSPOT, building on established research at the Trail Valley Creek and Havikpak Creek Research Stati... Show moreons in collaboration with Canadian partners (Drs. Phil Marsh and Oliver Sonnentag). The project will provide an important contribution to our understanding on how greenhouse gas sinks in pristine northern ecosystems function, potentially affecting current budget estimates and future projections of the methane and nitrous oxide budgets of the Canadian Arctic and beyond. The research team will use a combination of existing measurement infrastructure at Trail Valley Creek and new measurements of greenhouse gas exchange and auxiliary variables such as soil moisture, thaw depth, soil temperature, and soil CO2 concentrations. Greenhouse gas fluxes will be measured with portable greenhouse gas analyzers (LI-7810 and LI-7820 or similar) using the manual chamber technique, as well as with the existing automated chamber system that exists at Trail Valley Creek. The manual chamber flux measurements will be conducted on distinct vegetation and landcover units in the region including dwarf shrub and tussock areas, as well as lichen-covered soils. The flux measurements will make use of previously installed collars at the sites. We will also measure fluxes on additional locations using a small bucket chamber (volume: ca. 30L, diameter ca. 30 cm) that is placed on the ground surface, and twisted into the soil to a depth of a few cm, to ensure there is no exchange with the outside air. Trenching collars (diameter: max. 20 cm, length: 15–20 cm) will be installed at a subset of sites that show the largest methane and nitrous oxide uptake rates. These collars are meant to exclude the roots, and we will clip the aboveground vegetation from within these collars. This will allow us to measure soil microbial respiration, to partition CO2 fluxes into autotrophic and heterotrophic respiration, and to determine the effect of plants on methane and nitrous oxide uptake. All measurements will take place during the spring and summer months between June and September. Further, we will collect small (diameter ca. 10 cm, depth 10-20 cm) soil samples adjacent to the flux measurement locations for a laboratory incubation experiment, as well as for determination of soil physical-chemical properties such as carbon and nitrogen content, pH, water content and soil texture. We will only collect small amounts of soil samples, to minimize disturbance. From these soils, sub-samples (ca. 1 g or 5 mL) will be taken for microbial analyses of methane and nitrogen-cycling gene abundances. Similar measurements will be conducted in other parts of the Arctic, to compare how relevant greenhouse gas uptake is across the Arctic, and how the western Canadian Arctic compared to other arctic regions. Finally, we will use these observational data to model and estimate methane and nitrous oxide uptake in the Arctic. Since the research team will mostly be new in starting the research program in the Inuvik region, we will make use of contacts of our Canadian research collaborators that have been active in the region for decades. The research team is eager to establish and build contacts with community members, ideally involving them into the research. We would be happy to communicate and coordinate the planned research activities with local communities, and to learn which research deliverables are of interested to the community and should be shared. If there is interest, results will be shared with local government agencies. Members of the research team would also like to share this research via a public lecture in the Speaker Series at Aurora Research Institute. Data collected during this research project will be made publicly available in open access articles and databases. The fieldwork for this study will be conducted from: August 15 - September 10, 2025 June 10 - August 31, 2026 June 10 - August 31, 2027 Show less