城市土壤中重金属元素的积累及其微生物效应

与农村土壤相比,阿伯丁市城市土壤(路边土、公园土)的微生物特征发生了显著的改变,微生物基底呼吸作用明显增强,但微生物生物量却显著降低,微生物生理生态参数C_mic/C_org、q_co2值明显升高,Biolog数据显示城市土壤对能源碳的消耗量和速度显著升高.对重金属元素研究表明,与农村土相比城市土壤中重金属Pb、Zn、Cu、Ni已经有明显积累,化学形态研究表明Pb主要与氧化铁有关,Ni、Zn以残渣态为主,Cd以有效态为主,而Cu除有效态外,其它结合形态基本具有同等重要的意义.主成分分析表明,有效态Pb是控制城市土壤与农村土壤微生物特征差异的主要因素,其次为Zn,Cu和Ni的有效态和有机态亦有一定的作用效应.

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 C_mic/C_org and q_co2,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.