Stepan Alexandrovich Borkov

The characteristics of urban ecosystems, the morphological structure of profiles, the content of organic carbon, the amount of petroleum hydrocarbons, the pHН2О, and the density of soils were studied at 9 control sites in the floodplain along the Likhoborka River in the Northern Administrative District of Moscow. The river floodplain was dominated by Gleyic Fluvisol (Turbic) and UrbicTechnosol, which were heterogeneous in their morphological structure and properties. The organic carbon content in the AYtr horizon of reclaimed soils reaches 4% or more, while it is less than 1% in the UR and TCH horizons of UrbicTechnosol. Alkalization to pHН2О7.4–8.5 was observed not only in the upper horizons, but also in deeper layers (30–50 cm) of the soil, due to the numerous inclusions of construction materials and other waste. The density of the AY and AYtr horizons of Fluvisol varies from 0.8 to 1.3 gcm–3, while the TCH and UR horizons are compacted above 1.4 gcm–3. A paired analysis of the content of petroleum hydrocarbons in soils and bottom sediments was conducted, and contamination above 1000 mgkg–1.  was recorded along almost the entire 30-kilometer length of the Likhoborka River. Different types of distribution of petroleum hydrocarbons in soil profiles have been identified. Using correlation analysis, it has been found that a decrease in organic carbon content is accompanied by compaction and alkalization of the upper soil horizons. An increase in the level of petroleum hydrocarbon contamination is associated with an increase in organic carbon content and a decrease in pHН2О. The content of petroleum hydrocarbons is correlated across all layers of the upper 30-centimeter layer, but there is no correlation between the content of petroleum hydrocarbons in floodplain soils and bottom sediments along the Likhoborka River.