Comprehensive ecological assessments of human impacts on air quality in Beijing,China
人类活动对北京空气质量影响的综合生态评价

Aiming at providing scientific foundations for the policymakers to control urban air emissions, this paper explored two methodologies for evaluating the impacts of human activity (from 1983 to 2003), human and natural regulation (from the early days of Beijing city to 2003) on the air quality of Beijing's urban ecosystem through the Pressure-State-Response indicator system, ecosystem services estimating, and historical literature review. The results show that: (1) The three top ones are 2003 (0.619), 2001 (0.598), and 2002 (0.578); the three last ones are 1983 (0.392), 1984 (0.395), and 1985 (0.495). The total human impacts have an active tendency and increase with steady steps. (2) The active and negative impacts increased simultaneity from 1983 to 2003. Urban air quality improved since 1998. (3) The correlation coefficient between pressure index and response index is-0.995 (p<0.001). (4) The state index increased with the response index.As a result, the air quality improved, but the negative impacts dominated the active ones when the response index is not robust enough. (5) There are little human impacts on urban air quality before 1900. Bio-support services of Beijing city can regulate the impacts. However, after 1975, because bio-support services remarkably decreased, air quality became very severe. With the increase of human regulation ability, air quality of Beijing has been improved since 1998.