Ecological and Biological Monitoring of Urban Soils in St. Petersburg

A long-term study (2011–2023) of urbanozems (Urbic Technosols) was conducted along one of the largest highways in St. Petersburg, Stachek Avenue. The objective of this study was to comprehensively assess the dynamics of chemical (pH, contents of nutrients and heavy metals (Cd, Cu, Pb, Zn)) and biological (phytotoxicity, basal and substrate-induced respiration, microbial biomass, metabolic quotient qCO2) soil parameters. During the observation period, a significant increase in the content of mobile forms of cadmium, copper, and lead was revealed. The results of phytotesting (test object Avena sativa) demonstrated persistent phytotoxicity in some parts of Stachek Avenue. Microbiological analysis showed an increase in basal respiration and microbial biomass carbon content in 2023, though the values of the metabolic quotient (qCO2) significantly exceeded the background level for undisturbed soils attesting to the ongoing anthropogenic stress. The monitoring results indicate the long-term accumulation of pollutants related to vehicles under conditions of intensive traffic load.