Spatial Patterns of Carbon and Nitrogen in Soils of the Barents Sea Coastal Area (Khaypudyrskaya Bay)

Abstract

Concentrations of total carbon and nitrogen were measured by gas chromatography method, and the carbon content of inorganic compounds was determined by the volumetric method in soils of undisturbed coastal landscapes of the Barents Sea (Khaypudyrskaya Bay). Two groups of soils were specified. The first group included saline marsh soils formed under flooding by tidewater and surging seawater. The second group included soils of tundra ecosystems, which were subjected to precipitation of marine aerosols. In the first group, the content of C_org varied from 5 to 75 g/kg, the content of N total varied from 1 to 5 g/kg, and the C_org/N_tot ratio varied from 10 to 18. Humus-accumulative horizons buried under recent marine sediments were described in the middle part of the marsh soil profile. In the second group, the contents of C_org was 430–470 g/kg and N_tot 4–7 g/kg. The C_org/N_tot ratio in the surface peat horizons equaled to 64–95 g/kg and decreased by three–seven times in the deeper layers. The soils of the low-level marshes flooded each tide and especially their surface horizons contained more inorganic carbon than any other soils. Mass fraction of inorganic carbon varied from 4 to 20% of the total carbon content. Seawater and carbonate-containing rocks could be the source of the inorganic carbon. A correlation was found between the contents of C_org and N_tot in soils and in plant communities growing on these soils. Additional input of C_org and N_tot into marsh soils was due to the living activity of birds and to organic substances in seawater.