长春市土壤重金属化学形态与土壤微生物群落结构的关系

Relationship between chemical forms of some heavy metals and the microbial community structure in soil in Changchun urban

采用样品采集、室内分析和多种数据统计方法相结合的方法,研究了长春市土壤重金属化学形态与土壤微生物群落结构的关系。结果表明:长春市土壤重金属(Pb、Cd、Cu、Zn和Ni)不同化学形态对土壤微生物群落结构影响明显不同,碳酸盐结合态的Pb和Ni对放线菌的生长繁殖具有刺激作用,碳酸盐结合态Zn对细菌的生长繁殖具有刺激作用,铁锰氧化物结合态和有机结合态的Zn与有机结合态Cu对细菌、放线菌的生长繁殖具有刺激作用。土壤理化性质对重金属化学形态与微生物群落结构之间的关系影响很大,其掩盖了土壤重金属化学形态对土壤微生物群落结构特征的影响,有机质含量、电导率、阳离子交换量掩盖了重金属化学形态对细菌、放线菌和微生物总数的影响,自然含水率掩盖了重金属化学形态对多样性指数的影响。采用重金属的化学形态评价重金属对土壤微生物参数的影响更合理,而且在确定评价长春市土壤重金属污染状况指标时,应该剔除土壤理化性质的影响。选择有机结合态Cu、铁锰氧化物结合态Zn与微生物群落多样性指数相结合来评价长春城市土壤重金属Cu和Zn的污染状况。

The relationship between chemical speciation of heavy metals and the microbial community structure in Changchun urban soil was studied by the sample collection, laboratory analysis and various kinds of statistics methods in this work. The experimental results indicated that the different chemical forms of heavy metals had significant different impacts on microbial community structure The growth of ray fungi was stimulated by carbonate-Pb and carbonate-Ni., and the growth of bacteria was stimulated by carbonate-Zn, and the growth of ray fungi and bacteria were stimulated by OB （organic bound）-Cu, Fe-Mn oxides of Zn and OB （organic bound）-Zn. The influence of soil physicochemical properties on the relationship between chemical forms of heavy metals and microbial community structure was great, which hid the influence of chemical forms of heavy metals on the microbial community structure The influence of chemical forms of heavy metals on bacteria, ray fungi and microbial count was hid by organic content, conductivity and cation exchange capacity, and the influence of it on diversity indices was hid by natural moisture. The chemical forms of heavy metals were more suitable for assessing the influence of heavy metals on parameters of soil microorganisms. The effect of soil physicochemical properties should be canceled when establishing the evaluation indexes for heavy metals pollution in Changchun urban soil. The combination of OB （organic bound）-Cu, Fe-Mn oxides of Zn and diversity index of microbial community were used to assess the pollution of Cu and Zn in urban soil in Changchun city.