长春市土壤重金属化学形态与土壤微生物量、微生物商和代谢商之间的关系

Relationships between the chemical forms of heavy metals and the microbial biomass,microbial quotient,metabolic quotient of soils in Changchun City

通过样品采集和室内分析相结合的方法研究了长春市城市土壤重金属化学形态与土壤微生物量、微生物商和代谢商之间的关系,以及土壤理化性质对重金属形态与土壤微生物量、微生物商和代谢商之间关系的影响.实验结果表明:城市土壤环境的空间异质性是引起城市土壤微生物参数的空间分异性的主要原因.长春市土壤重金属(Pb、Cd、Cu、Zn和Ni)不同的化学形态对土壤微生物量、微生物商和代谢商的影响明显不同,且土壤理化性质对它们之间关系的影响比较显著.采用重金属化学形态与微生物学指标相结合的方法评价长春市土壤重金属污染状况时,应该剔除土壤理化性质的影响.可以选择碳氮比与有机结合态Ni含量相结合的方法评价长春市土壤重金属污染状况或者确定重金属污染的临界浓度.

The relationships between chemical forms of heavy metals and the microbial biomass,microbial quotient,metabolic quotient of Changchun urban soils,as well as the effects of the physicochemical properties of soils on their relationships were investigated by the methods of sample collection and laboratory analysis in this work.The experimental results indicated that the spatial heterogeneities of the soil microbiological parameters were mainly resulted from the spatial heterogeneities of the urban soil environment.The different chemical forms of heavy metals（Pb,Cd,Cu,Zn and Ni） had different impacts on the microbial biomass,microbial quotient,metabolic quotient of soils.The relationships between chemical forms of heavy metals and the microbial biomass,microbial quotient,metabolic quotient of soils were influenced by the physicochemical properties of soils obviously,and the effects of chemical forms of heavy metals on the soil microbiological parameters were amplified or concealed by the soil organic matter content and pH,etc..It will be more suitable for assessing the contamination of heavy metals by combining the chemical forms of heavy metals with the microbiological parameters.Besides,the effects of soil physicochemical properties should be eliminated when establishing the evaluation indexes for heavy metals in Changchun urban soils.The combination of the microbial quotient and the content of organic-bond Ni can be adopted to assess the contamination of heavy metals in soils and determine the critical concentration of heavy metals pollution.