Base de données de recherche des TNO

Régions: Dehcho Region

Objectif(s): To understand and predict how lakes in discontinuous permafrost peatlands are changing in response to climate warming and loss of permafrost.

Description du projet: This licence has been issued for the scientific research application No. 5774. Understand and predict how lakes in discontinuous permafrost peatlands are changing in response to climate warming and loss of permafrost. Field activities will focus on three regions/objectives: (1) Inferring long-term environmental change in the Five Fish Lakes (Lue Túé Sulái) – We will collect short (~30-50 cm) sediment cores from Ezáa Lue Túe (Ekali Lake), Tl’onie Túé (Sanguez Lake), Tlitetii (Gargan Lake), Dechi Ná?a (Deep Lake) and Tthets’éhk’e’ (McGill Lake) near Jean Marie River. Sediment cores record a history of environmental change that can be read by analyzing chemical and biological fossils that preserve in the sediments. We will use a gravity core with a diameter of 8.6 cm to collect the sediments, using the winter lake ice as a stable platform to collect the cores. Our coring methods are non-destructive and take ~1 hour per lake to complete. We will hire community members from Jean Marie River to assist us with accessing and coring the lakes. The sediment cores we collect will record the last ~300-500 years of the lakes’ histories. We will analyze cores to track changes in lake dissolved organic carbon, mercury, and phytoplankton communities. (2) Climate change implications for algal blooms in Trout Lake - This project will mobilize and expand upon existing monitoring and research in the Trout Lake watershed. Dehcho-AAROM deploys continuous data loggers at 3 locations in Trout Lake to monitor water temperatures and other water quality parameters. We will analyze long-term trends in the data and deploy additional loggers in areas of Trout Lake we predict will have the potential to act as hotspots for algal bloom formation. The team will perform water quality and phytoplankton community monitoring routinely over the open-water season and will provide Sambaa K’e with phytoplankton kits to sample and preserve any bloom events that may occur in between our regular samplings. We will work within an existing community-based mapping program to add capacity for recording and geolocating bloom events. We will collect water samples from Trout Lake tributaries being monitored for permafrost thaw and have them analyzed for routine water chemistry parameters at the Taiga Environmental Lab in Yellowknife. (3) Shallow lakes as recorders of post-wildfire landscape succession – This project will study small, shallow lakes at or near the Scotty Creek Research Station as sentinels of short- and long-term landscape changes following wildfire. We will conduct long-term ecological research on water chemistry, plankton communities, and lake physical parameters (light, temperature) in 5-10 small, shallow lakes we previously sampled in 2019. The plan is to begin these activities in the summer of 2023, but this is dependent on whether the Scotty Creek Research Station will be ready to host researchers. We may need to scale back our activities or delay until summer 2024, and will make decisions on fieldwork plans in consultation with the Li´i´dli?i? Ku´e´ First Nation. In winter of 2024, we plan to collect long sediment cores spanning thousands of years to reconstruct past forest fire events using charcoal macrofossils in the sediments and study subsequent changes in the land and water using biomarkers (chemical fossils) and aquatic biological fossils preserved in sediments. The research objectives and activities at the Five Fish Lakes are in partnership Jean Marie River, and the research at Sambaa K’e is in partnership with Sambaa K’e FN. Dehcho Guardians will be hired and trained through the project. Findings will be communicated through sustained consultation with LKFN, SKFN, and JMRFN, including monthly Zoom meetings where Scotty Creek researchers and Dehcho FN partners discuss research findings and plans. Results will also be disseminated at regional and/or community meetings, in plain language reports, story maps, and participation in “on-the-land” (or “with-the-land”) workshops and outreach events. Data will be uploaded to the NWT Discovery Portal and Mackenzie Datastream, and copies of all publications will be provided to stakeholders and community partners. LKFN will be co-owners of the data collected at Scotty Creek, SKFN will be co-owners of data collected from Trout Lake, and JMRFN will be co-owners of data collected from the Five Fish Lakes. We applied for an LKFN research license on Feb. 5, 2024. The fieldwork for this study will be conducted from: June 23 - September 30, 2024