A new dataset of soil Carbon and Nitrogen stocks and profiles from an instrumented Greenlandic fen designed to evaluate land-surface models.

Arctic and boreal peatlands play a major role in the global carbon (C) cycle. They are particularly efficient at sequestering carbon due to their high-water content which makes primary productivity exceed decomposition rates. Though, their future in a climate-change context is quite uncertain in terms of carbon emissions and carbon sequestration. Nuuk-fen site is a well-instrumented greenlandic site of particular interest for testing and validating land-surface models with monitoring of soil physical variables and greenhouse gas fluxes (CH₄ and CO₂). But knowledge of soil carbon stocks and profiles is missing. This is a crucial shortcoming for a complete evaluation of models, as soil carbon is one of the primary drivers of CH₄ and CO₂ soil emissions. To tackle this issue, we measured for the first time soil carbon and nitrogen density, profiles and stocks in the Nuuk peatland, at the exact location of fluxes monitoring. Measurements were made along two transects. Measurements horizontal resolution is 5 meter, vertical resolution ranges from 5 to 10cm. Mean soil carbon density is 50.2 kgC.m^-3. These new data are in the range of those encountered in other arctic peatlands. This new dataset can contribute to further develop joint modelisation of greenhouse gas emissions and soil carbon in land-surface models. [ABSTRACT FROM AUTHOR]