[Accumulation of heavy metals in urban soils and impacts on microorganisms]

Compared with rural soils, urban soils in Aberdeen city possessed obviously different microbial features: higher in microbial basal respiration strength, and microbial ecophysiological parameters Cmic/Corg and qCO2, but lower in microbial biomass, also much more rapid in consuming carbon sources deduced from Biolog data. Urban soils showed different characteristics in heavy metals as well. Apparent accumulation of Pb, Zn, Cu, Ni were observed, in which Pb mainly related with iron oxides, Ni, Zn existed in residual forms, Cu exhibited same importance of different chemical forms but for soluble forms. Principal component analysis results reflected the overwhelming factor to control the difference of microbial features between urban and rural soils was soluble Pb, then soluble Zn, soluble and organic bonded Cu and Ni also contributed in some degree.