Carbon accumulation features in different functional zones of cities in the steppe zone.

This article presents findings on the study of content, profile distribution, and reserves of various carbon forms (organic carbon (TOC) and inorganic carbon (IC)) in Urbic Technosols and Ekranic Technosols within the residential zone of the city, alongside zonal Calcic Chernozems in the recreational zone of Rostov-on-Don, Aksai, and Bataysk. It was revealed that the TOC content in the upper horizons of Urbic Technosols is significantly lower than in the chernozem horizons of fallow areas, registering at 2.59 ± 0.79% and 3.25 ± 0.94%, respectively. IC exhibits an inverse trend, with maximum content observed in the upper horizons of Ekranic Technosols. Down the soil profile, disparities in TOC and IC contents are mitigated. This specificity in TOC accumulation and profile distribution signifies a "bipartite" profile alteration in buried chernozems, affecting solely the upper stratum rather than the entire soil profile. The presence of woody vegetation in the dry-steppe zone positively influences TOC accumulation. Calcic Chernozems beneath woody vegetation showcase the highest TOC reserves within the 30-cm layer (10.61 ± 1.45 kg/m). Calcic Chernozems of fallow areas under natural steppe vegetation contain 8.94 ± 1.75 kg/m, Technosols of the residential zone 8.44 ± 2.47 kg/m. For Technosols of the residential zone, a weakening of the dependence of TOC and IC content on the depth of the soil horizon is observed.