It is presumed that significant quantities of carbon are stored in permafrost soils and that the thawing permafrost could substantially raise atmospheric carbon dioxide concentration. ADAPT has developed a standard protocol to coordinate and increase common fieldwork sampling/record efforts in order to help document and precise the assessments of carbon stock in the permafrost and the active layer from sites all across the Canadian Arctic.
According to the active layer sampling standard protocol for C/H/N determination, soil samples for each site are collected in 2 sub-sites, chosen according to significant differences (e.g. soil type, vegetation type/cover, soil moisture, topography, etc.), and at 3 different locations (i.e. 3 replicates/profiles by sub-site). The active layer is sampled using the ADAPT soil sampler which allows for bulk density determination at each depth (surface, -5 cm, -15 cm, -30 cm, -40 cm and at max. depth) starting from top to bottom. The stainless tube is slowly driven into the soil in order to take an undisturbed soil sample. Soil samples are stored in a cooler and in the dark until they are treated in laboratory. All soil samples are analysed at the Radio-carbon laboratory of the CEN, where the total mass content of the carbon (C), nitrogen (N) and hydrogen (H) are calculated by combustion using a LECO CHN628 Elemental Determinator. Prior to be analysed, samples are 1) weighed (as well as the stainless cylinders) to determined the bulk density of the soil, 2) dried and weighed again to determine the water content, and 3) grinded and mixed using a mortar and pestle. Only a small portion the prepared soil sample is needed for the LECO CHN628 Elemental Determinator.
The carbon, nitrogen and water content data come from 10 different sites: Beaver Creek, Daring Lake, Illisarvik (Mackenzie Delta), Cape Bounty, Vallée des Trois (VDT- Umiujaq), BGR (Umiujaq), SAS (Kuujjuarapik), Ward Hunt Island, Bylot Island and Churchill. For more details on ADAPT Standard Protocols, please visit the ADAPT ADAPT website
