NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, water quality, climate change, permafrost thaw, waterflow monitoring

Objective(s): To link long-term records of ground temperature and permafrost conditions with changes in landcover and water quality of adjacent ponds and lakes.

Project Description: This licence has been issued for the scientific research application No.5568. The primary objective of this project is to link long-term records of ground temperature and permafrost conditions with changes in landcover and water quality of adjacent ponds and lakes. In other words, how thawing permafrost alters terrestrial and aquatic ecosystem properties. Along the Mackenzie Valley corridor exists unparalleled permafrost monitoring infrastructure established by the Geologic Survey of Canada. These sites were established starting in 1984 to better understand changing permafrost conditions in response to hydrocarbon exploration and development in this region. At each site, a borehole was drilled and either a ground thermal cable or a thaw tube was installed to monitor changes in permafrost conditions. These sites have been continuously monitored for between 20 and 38 years providing an incredible, long-term record of change. We are making use of these records to quantify ecological responses to permafrost thaw including impacts on wildlife forage availability (e.g., caribou lichens), forest structure, composition and productivity, and water and sediment quality in adjacent ponds/lakes to evaluate relationships between permafrost thaw, landcover conditions, and downstream water quality. The research team will access 22 sites roughly at the edge of the subarctic boreal-tundra transition, most of them on continuous permafrost and all of them adjacent to small ponds or lakes. The selected sites are within 130 km of our base camp in Inuvik, NT, Canada. Thirteen of these sites are helicopter access, while the rest are road accessible. At each site, logger data will be downloaded from the permanent monitoring bore holes instrumented with thermistor strings. These thermistors provide data on ground temperature profiles and active (seasonally thawed) layer thickness (ALT). The presence or absence of ground ice will be recorded and the ALT at the time of sampling. Following the previous sampling protocol of 2021 (the Sahtu sites within this permafrost monitoring network), at each site we will establish circular plots of variable radius to sample a minimum of ten black spruce individuals. A 30 x 2m belt transect will be established to characterize stand structure and composition. Along this transect, five 1 m2 vegetation plots will be placed at regular intervals to quantify composition and abundance of ground vegetation (vascular and nonvascular plants). These vegetation plots will be paired with shallow soil cores (10 cm diameter, maximum 50cm depth) to quantify carbon and nutrient stocks in the surface soils. One permafrost core per site will be extracted using an auger to quantify carbon and nutrient stocks in the near surface permafrost. Finally, sediment and water samples will be collected from adjacent ponds/lakes to assess the impacts of permafrost and landcover conditions on surface sediment and water quality (leached macronutrients and contaminants: dissolved organic carbon, total and dissolved nitrogen and phosphorus, total and dissolved mercury, and methylmercury). The communication plan involves two key components: 1. Involvement of community members in research: involve community members as part of the research teams through collaboration with local guardian programs such as the Imaryuk monitors whenever possible. Opportunities will be provided for these individuals to be as involved in all stages of the research as they would like to be. Local wildlife monitors will be hired whenever the helicopter is not staying on site or when road sampling is occurring. 2. Communication of progress and results back to communities and NWT stakeholders: data and findings will be conveyed to the community through a variety of plain language materials. Examples of this include, but are not limited to infographics, digital stories, and reports. Planned outreach also includes presentations at schools intended to engage youth in the research happening in their communities. All data will be made openly available and accessible to the public to ensure access by NWT stakeholders, communities, or future research teams. Data and publications will also be shared directly with interested ISR and Gwich’in organizations. The fieldwork for this study will be conducted from: July 01 - August 30, 2023