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森林是具有重要服务功能的生态系统之一,在城区和郊区都普遍存在,但对于森林土壤微生物群落特征的城郊差异研究却很少。本研究在北京城市与郊区选择三种相同树种(油松Pinus tabulaeformis、侧柏Platycladus orientalis和毛白杨Populus tomentosa)的森林,主要研究比较了土壤微生物量碳、微生物群落结构和功能多样性的城郊差异。结果表明,郊区森林的土壤微生物量碳含量显著高于城区(郊区微生物量碳为367.29 mg kg-1,城区为294.23 mg kg-1)。同一树种下郊区微生物活性高于城区,差异未达到显著。微生物多样性和均匀度城郊差异不明显;但树种间存在一定的差异,城区毛白杨林下土壤微生物群落的均匀度显著低于柏树与油松,多样性指数显著低于柏树。结果表明城市化过程对城市土壤微生物量以及微生物群落的结构和功能有一定影响,且不同树种对于这种影响存在差异。随着城市化加快,城乡梯度上土壤微生物量碳的城乡差异明显,而土壤微生物群落结构、功能的差异有减小的趋势。
As one of the ecosystems with important service functions, forests are common in both urban and suburban areas. However, there are few researches on the suburban differences in the characteristics of forest soil microbial communities. In this study, we selected three forests of Pinus tabulaeformis (Pinus tabulaeformis, Platycladus orientalis and Populus tomentosa) in urban and suburban areas of Beijing, and compared the suburban differences in soil microbial biomass carbon, microbial community structure and functional diversity . The results showed that the soil microbial biomass carbon content in suburban forests was significantly higher than that in urban areas (367.29 mg kg-1 of microbial biomass in the suburbs and 294.23 mg kg-1 in urban areas). Under the same tree species, the activity of microorganisms in the suburbs was higher than that in urban areas, and the difference was not significant. There was no significant difference in the diversity and evenness of the suburb in the suburbs. However, there were some differences among the species. The evenness of soil microbial community under Populus tomentosa in urban area was significantly lower than that in Cypress and Pinus tabulaeformis, and the diversity index was significantly lower than that in Cypress. The results show that the urbanization process has an impact on the microbial biomass and the structure and function of the microbial community in urban areas, and different species have different effects on this. With the acceleration of urbanization, the difference between urban and rural areas of soil microbial biomass carbon in urban and rural gradients is obvious, but the difference of soil microbial community structure and function tends to decrease.