Coastal Labrador peatland permafrost inventory

Northern peatlands cover approximately four million km², and about half of these peatlands are estimated to contain permafrost and periglacial landforms, like palsas and peat plateaus. Peatland permafrost environments are known to be sensitive to climate warming and ecosystem modifications, so understanding the distribution of these ice-rich landforms is important for predicting thermokarst potential, hydrological and vegetation change, and carbon cycling activities. We applied a multi-stage consensus-based approach to develop a first inventory of peatland permafrost complexes in Labrador, spanning from 51 to 61°N, with a focus on the area within 100 km of the Labrador Sea and Gulf of St. Lawrence coastline. A team of three mappers identified a total of 2092 prospective peatland permafrost complexes in coastal Labrador and adjacent parts of Quebec using high-resolution satellite imagery available via Esri ArcGIS Online (Maxar Vivid imagery, 0.5 m spatial resolution, 5 m spatial accuracy, imagery acquisition dates 2010-2020) (Esri, 2022). Each prospective peatland permafrost complex was subsequently reviewed by two of the three mappers into classes of likely, possible, and unlikely peatland permafrost complexes. Prospective complexes that were evaluated by both reviewers as containing peatland permafrost were classified as likely peatland permafrost complexes, while prospective complexes with conflicting evaluations were classified as possible peatland permafrost complexes. Interpretation of peatland permafrost presence or absence was supported by field and imagery-based validation efforts at 557 prospective peatland permafrost locations, 331 of which contained peatland permafrost. Out of 2092 initial wetland complexes, 1120 were interpreted as likely containing peatland permafrost, and 186 were interpreted as possibly containing peatland permafrost. Likely peatland permafrost complexes were mostly found in lowlands within 22 km of the coastline, in locations with corresponding mean annual air temperatures of up to +1.2 °C (1980-2010). These inventory results provide an important baseline for future mapping, modelling, and climate change adaptation strategy development for the region. Updated versions of the inventory will continue to be made available. Esri. (2023). World Imagery, https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9. Accessed from September 2020 to June 2023.

Forget, Anika (Northern Environmental Geoscience Laboratory, Department of Geography and Planning, Queen’s University, Kingston, ON)

Tutton, Rosamond (Northern Environmental Geoscience Laboratory, Department of Geography and Planning, Queen’s University, Kingston, ON; Global Water Futures, Wilfrid Laurier University, Yellowknife, NT)

Purcell, Meredith (Torngat Wildlife, Plants, and Fisheries Secretariat, Happy Valley-Goose Bay, NL)

Colyn, Victoria (Northern Environmental Geoscience Laboratory, Department of Geography and Planning, Queen’s University, Kingston, ON)

Thiessen, Rabecca (Department of Geography and Environment, University of Lethbridge)

The authors acknowledge the Nunatsiavut Government, the Nunatsiavut Research Centre, the NunatuKavut Community Council, and the Innu Nation for their support of research conducted on traditional Inuit and Innu lands. Funding for this research was provided by the Natural Sciences and Engineering Research Council of Canada, the Northern Scientific Training Program, and Queen’s University.

Published

Version 1.1.0 (2022-2022) - Updated January 24, 2023

Version 1.0 (2021-2021) - Updated April 21, 2022

Version 1.2.0 (2023-2023) - Updated June 12, 2023