Blue Carbon Stocks and Carbon Dioxide Emission from Soils of Marsh Ecosystems of the Pomor Coast of the White Sea

The study is aimed at solving fundamental problems of soil science and ecology related to the assessment of the carbon budget in coastal soils and ecosystems of the Arctic and Subarctic, as well as their functioning in changing climate conditions. The study estimated for the first time the stocks of “blue carbon” and the emission of carbon dioxide from soils of marsh ecosystems at the Pomor coast of the White Sea. Carbon stocks in the most seaward part of the coastal zone accumulate due to the input of allochthonous, thalassogenic organic matter: mean stocks at the lower marsh level are 25.5 ± 4.3 t/ha. At a distance from the boundary of daily flooding, the stocks of soil carbon are mostly formed by the biogenic accumulation of organic matter: the mean value at the upper marsh is 37.5 ± 23.4 t/ha. Soils of marsh ecosystems at the Pomor coast of the White Sea are characterized by low values of carbon dioxide emission (98 ± 16 mg CO2/(m2 h), July-August 2023), which attests to their low biological activity.