Pedo-chemical Perturbations in Soils from Green Ecosystems of the Sofia City (Bulgaria)

In view of the role of cities for ensuring a favorable living environment, it is important to study the urban soils since they are formed and developed under the impact of different by degree and type anthropogenic perturbations. Pedo-chemical studies of urban soils may capture the evolution of different soil components and reveal the different stages of soil matrix transformation. Using pedogenic and chemical analyses, the present article aims to present the trends of perturbations of the mineral and organic matrix of urban soils located along the direction of increasing gradient of urbanization in cursory investigated soil zones belonging to the residential and industrial districts of the Sofia city (Bulgaria). The results obtained show that anthropogenic alterations are predominantly associated with morphological reorganization of some soils rather than soil compaction and structure loss. The increase of exchangeable hydrogen content provoked by fulvic acid production and leaching can be attributed to the current natural perturbations. Anthropogenically induced chemical changes could be linked with increase of the mineral N flux and high ammonium content which will influence the existing acid-base status of Sofian soils.