| The population was large in Shanghai and there were a large number of manufactories, and the pollution sources were complicated. The contents and pollution characteristics of Cu, Zn, Pb, Cd, Cr, Ni and their forms, black carbon, soil enzyme activity were analyzed and evaluated in the typical municipal green-belts soil from Shanghai in this paper, which would provide evidence for reasonable governance and protection of city. The results were showed as follows:(1) The main from of Cu was organic form. As for Zn,the Fe-Mn oxides and residual forms were the main fraction. Pb and Ni existed mainly in residual form.Cr was mostly in the organic and residual forms. While the exchangeable from was the predominant fraction for Cd, and accounted for 31.31% of the total.There are significant correlation between Cu,Zn,Pb,Cd,Cr,Ni and their forms, but the correlation was different among the different forms.(2) The effect of the soil properties on different forms of heavy metals were different. CaO,Fe2O3 and MnO were beneficial to the formation of organic and residual forms, which could reduce the activity of heavy metals.With respect to Cu,Zn,Pb,Cd,Cr and Ni,the correlation of the Fe-Mn oxides Zn and Fe2O3,MnO was the best.(3) The distribution of heavy metals was also influenced by different land uses. The activity of Cu was the highest in office and residential area, Zn activity was the highest in mechanical plant, the content of exchangeable Cd was the most in the chemical-reagent factory. While Pb was existed as the inert form, the harm of which was light relatively. Ni existed mainly in residual form, but the content of Fe-Mn oxides Ni was higher in iron-steel factory and ship-building factory than that of in mechanical plant and office and residential area.(4) The content of black carbon ranged from 0.70 g·kg-1 to 78.89 g·kg-1 in typical green-belts soil from shanghai,and the average was 11.38 g·kg-1.The content of black carbon was the highest in mechanical plant,and the average content of black carbon was 18.30 g·kg-1.There were a significantly positive correlation between black carbon and organic carbon and BC/OC.(5) The content of black carbon were also different for the different land use patterns. The content of black carbon and BC/OC were the lowest in office and residential area, and the maximum existed in the iron-steel factory,the average of which was 0.88.The order of the average of BC/OC are:ship-building factory>iron-steel factory>mechanical plant> chemical-reagent factory>office and residential area.(6) Soil enzyme activities were affected by different environmental factors in typical green-belts soil from Shanghai.Catalase activity was mainly influenced by soil bulk density, pH, CEC and Cr. The influence of organic matter, hydrolysis of N, Pb and Zn on alkaline phosphatase was greater than the other. There are a significant effect of the CEC, pH, bulk density and hydrolysis of N on dehydrogenase. Urease activity was mainly affected by hydrolysis of N, CEC, pH and bulk density. And the influence of catalase, alkaline phosphatase, dehydrogenase and urease on soil nutrition was higher. However, the effect of Cu, Zn, Pb, Cd, Cr and Ni on soil enzyme was small relatively. Alkaline phosphatase was sensitive to nutritional status of the soil.
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