WP 3: Carbon and nitrogen pools in permafrost terrain; potential mobilization and feedback mechanisms following permafrost thawing and collapse

The aim of this Work Package is to provide accurate information on below-ground organic carbon (C) and nitrogen (N) storage and its partitioning in the landscape (mineral vs. organic soils) and in the soil profile (separating active layer, cryoturbated and permafrost soil horizons) at all primary PAGE21 project field sites.

The WP will focus on sites at which detailed assessments have not previously been carried out (Samoylov, Kytali, Svalbard and Abisko). These new datasets will be complemented with pre-existing information for other PAGE21 field sites (Cherskii, Vorkuta and Zackenberg), where fieldwork will be limited to filling in any gaps that exist in the datasets. The soil organic matter (SOM) lability and N availability across landscape units and soil genetic horizons will be assessed using a suite of geochemical and  biogeochemical methods. Potential C and N mobilization and subsequent conversion to greenhouse gasses (GHGs) CO2, CH4 and N2O, will be assessed through a number of field manipulations and  laboratory experiments, with a focus on the net effect of current permafrost layer contributions to GHG emissions and active layer redox-processes.

Process studies will aim to integrate periglacial, geochemical, microbial, and plant interactions which, in close collaboration with WP4, will contribute to improvements in the modelling of processes generating C and N fluxes in WPs 6 and 7. The relationship between SOM quantity and quality along circum-Arctic ecoclimatic, pedogenetic and permafrost gradients will be investigated through a multivariate meta-analysis of available local and regional pedon datasets. For this purpose, PAGE21 results will be complemented with North-American datasets of similar detail (from Kuparuk, Alaska and Tulemalu, Canada). The analysis will make use of gradient analyses and  semivariogram modelling techniques to assess circum-Arctic relationships between SOM quantity and quality and environmental gradients in climate, permafrost, topography, landscape age and soil parent material. Results from local datasets will be scaled up to regional and circum-Arctic scales, based on land cover classifications and soil maps.

WP Coordination:

Stockholms Universitet

Principle Investigator:

Peter Kuhry

Collaborators:

University of Copenhagen

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