南京市不同功能城区表土微生物碳氮与酶活性分析

Topsoil microbial carbon and nitrogen and enzyme activity of different city zones in Nanjing,China

城市土壤环境污染及其对城市环境质量与社会生活的影响 ,已引起公众重视 ,但对其生境问题了解不够。将南京城市土壤划分为 6种功能区 (工业区、交通商业区 )、老居民区、新开发区、城市广场和风景区 ,分析了各功能区土壤的微生物量碳、氮及脲酶和过氧化氢酶活性 ,探讨其对城市土壤环境质量的指示意义。结果表明 ,微生物量以公共绿地、风景区较高 ,以新开发区和交通商业区为最低。主成分分析表明 ,脲酶活性、微生物量碳、过氧化氢酶活性对公因子的贡献最大。与自然土壤相比 ,南京城市土壤碳氮比、Cmic/Corg变化范围均增大 ,表明土壤微生物区系受到人为活动较大的干扰。

Much attention has been paid to the pollution of urban soils and its impact on environmental quality and social development.But little has been known about its microbial habitat.In this paper,the Nanjing city was divided into six zones as smelter industry,inner commercial,inner residence,newly developed,urban green area and preserved scenic zones.The microbial biomass C and N,urease activity and catalase activity in these six zones were analyzed and the influencing factors on their distribution and variation were discussed.High contents of microbial biomass C (C mic) and N (N mic) was found in the green area and preserved scenic zones,while low contents in the newly developed and the inner commercial zones.Principal component analysis showed that urease activity,C mic and catalase activity were the main parameters contributing dominantly to the principle factors.Compared with the results of agricultural soils reported elsewhere,the urban soils of Nanjing city had wide variation both in the ratio of C/N and in C mic/C org.All these results supported that the urban environment was largely disturbed by anthropogenic stress and the microbial community was greatly modified.