Soil carbon and nitrogen stocks in polygonal-fissure mires of southern tundra in Western Siberia

Based on the experimental data, soil carbon and nitrogen stocks are estimated in polygonal-fissure mires of southern tundra in the north-eastern part of Western Siberia. The field experiments were carried out in 2014-2017 at the site located in tundra zone of the Yamal-Nenets Autonomous District. Active soil layer (seasonally thaw) and upper frozen layer are investigated. The seasonally thaw layer of tundra soils has been subdivided into two horizons: active upper layer (down to 15 cm depth) and active lower layer (from 15 cm down to the permafrost). Our research has shown that the values of organic carbon and total nitrogen storages in mires under study can be estimated as 14.1±3.6 kgC/m² and 0.4±0.1 kgN/m² for the active soil layer and 12.9±2.8 kgC/m² and 0.5±0.1 kgN/m² for the upper frozen layer. Organic carbon and total nitrogen stocks for the active soil layer and upper frozen layer in polygonal-fissure mires are evaluated as 172.0±29.1 ktC and 5.4±1.2 ktN.