Carbon accumulation in peatlands of the Mordovian Natural Reserve during the Holocene

The paper presents the results of the study of the Holocene carbon accumulation in four peatlands of different genesis and landscape position in the area of the P.G. Smidovich Mordovian State Nature Reserve, located on the southern border of the coniferous-broadleaved forests of the East European Plain. The analysis of the carbon content in the peat showed that in mineratrophic peat composed of vascular plant remains the organic carbon content is 46.9-60.9% (average 54.6%) and these values are generally higher than the carbon content in poor fen with woody-Eriophorum-Sphagnum and Eriophorum-Sphagnum peat, 43.6-50.1% (average 47.8%). Low carbon values (39.2%) were found for grass and woody-grass low decomposed peat in wet karst bog. The carbon accumulation rate in peatlands ranges from 5.2 to 84.9 g C/m² per year, with an average value for the entire Holocene of 22.5 g C/m² per year. Analysis of the distribution of carbon accumulation rate (CAR) in peat deposits by depth and age revealed similar patterns of carbon deposition in the four peatlands studied: an increase in CAR during the period 10500-7500 cal yr BP (calendar years before present) and a decrease in the intensity of carbon accumulation during the period 7500-3500 cal yr BP, which partly coincides with the Holocene Thermal Maximum, when the climate was warmer and drier than the modern one. The formation of the upper horizons of the peat deposits of the bogs and the carbon accumulation in the late Holocene showed individual specificity of different peatlands, with a general trend of CAR growth.