Plant litter decomposability and microbial respiration in urban soils

Dataset for the examination the effects of plant litter decomposability on soil microbial respiration and organic C stocks in five urban green areas within the Sirius Federal Territory (Black Sea region, humid subtropical climate): deciduous forest, shrubland, grassland, ruderal area, and turfgrass. The kinetic analysis of plant litter decomposition, measured over a 12-week incubation, was combined with the investigation of CO2 efflux from soil and microbial biomass. The plant litter decomposability decreased as its C/N ratio increased. The content of potentially mineralized C in litter was similar across all urban green areas. The decay constant decreased progressively from turfgrass and grassland to shrubland and ruderal area, and finally to forest. A higher litter decay constant was associated with a faster rate of microbial respiration per unit of organic C content in soil. Soil organic C stocks were 20–38% higher in urban forest and area with ruderal vegetation than in turfgrass due to greater biostability of their litter and lower microbial activity in the soils of semi-natural green areas compared with those of completely transformed city ecosystems. Consequently, vegetation-specific urban green infrastructure management is important to regulate C storage in urban soils.