| Abstrakt: |
Urban soils contain a substantial pool of organic matter (OM), the decomposition of which leads to intensive CO2 emission that is important in terms of global climate change. The OM decomposition increases in line with soil temperature, and the magnitude of such effect largely depends on soil physicochemical properties. At the same time, the contribution of the functional microbial diversity on the temperature sensitivity of OM decomposition (Q10) is still poorly understood, especially for urban ecosystems. Consequently, our study was aimed at assessing the effect of microbial functional diversity on the Q10 value for urban soils with respect to physicochemical properties. Four parks were chosen in St. Petersburg, Moscow, Voronezh, and Krasnodar, located in different bioclimatic zones (southern taiga, mixed forests, forest–steppe and steppe, respectively). In each park, samples were taken from the topsoil (0–10 cm layer). In soil samples, OM decomposition was determined at 10, 20, 30, and 40°C for the subsequent calculation of Q10. The soil physicochemical (moisture, texture, pH, content of C, N, available P2O5 and K2O) and microbial (functional diversity, biomass) properties were determined as possible drivers of Q10. The Q10 value in urban topsoils mainly correlated with their texture, moisture, and C and N contents, while microbial functional diversity correlated with P2O5. No regular distribution pattern of Q10 and the studied soil properties of urban parks along the latitudinal gradient has not been found; however, a negative relationship between Q10 and the microbial functional diversity has been revealed (R2 = 0.50). Apparently, the high microbial functional diversity contributes to a decrease in temperature sensitivity of OM decomposition. [ABSTRACT FROM AUTHOR] |
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