title: Microbial biomass carbon and enzyme activities of urban soils in Beijing.
abstract: BACKGROUND
  To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing.
  
  
  METHODS
  Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon.
  
  
  CONCLUSIONS
  The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p < 0.01. It was shown that the older and the biologically more stable part of city exhibited higher microbial activity levels than the more recently developed part of the city and the road areas of heavy traffic. It was concluded that the land use patterns in Beijing urban soils influenced the nature and activities of the microbial communities.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 110016, China.
authors.forename: Meie
authors.initials: M
authors.lastname: Wang
authors.forename: Bernd
authors.initials: B
authors.lastname: Markert
authors.forename: Wenming
authors.initials: W
authors.lastname: Shen
authors.forename: Weiping
authors.initials: W
authors.lastname: Chen
authors.forename: Chi
authors.initials: C
authors.lastname: Peng
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Ouyang
mesh_terms: D018533:Biomass; D002244:Carbon / Q000032:analysis*; D002681:China; D002947:Cities; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D019216:Metals, Heavy / Q000032:analysis; D012987:Soil / Q000032:analysis / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*; D014510:Urease / Q000378:metabolism*; D043324:beta-Fructofuranosidase / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002244:Carbon; D043324:beta-Fructofuranosidase; D014510:Urease