• 研究报告 •

### 珠三角城市绿地CO2通量的环境响应特征

1. 1南京信息工程大学， 南京 210044；2广东省气候中心， 广州 510080；3东莞市气象局， 广东东莞 523086
• 出版日期:2012-01-08 发布日期:2012-01-08

### Environmental response characteristics of CO2 flux above urban green space in Pearl River Delta.

SUN Chun-jian1,2**, SHEN Shuang-he1, WANG Chun-lin1,2, ZHANG Jin-biao3, REN Qian2

1. 1Nanjing University of Information Science and Technology, Nanjing 210044, China;2Climate Center of Guangdong Province, Guangzhou 510080, China; 3Meteorological Bureau of Dongguan, Dongguan 523086, Guangdong, China
• Online:2012-01-08 Published:2012-01-08

Abstract: The net ecosystem exchange (NEE) of CO2 above urban green space is controlled by various environmental factors. To quantitatively analyze the environmental response of the NEE can provide valuable basis for the evaluation of carbon fixation effect of green space ecosystem and the optimization of urban green space distribution. Based on the CO2 flux data of Dongguan Botanical Garden in 2009 and 2010 measured by eddy-covariance method, this paper analyzed the relationships between the NEE and the environmental factors (photosynthetic active radiation (PAR), soil temperature (Ts), saturation vapor pressure differential (VPD), precipitation, and land cover distribution). The results showed that the absolute value of NEE increased with increasing PAR when the PAR was less than the light saturation point (1500 μmol photons·m-2·s-1), but presented a decreasing trend when the PAR was higher than the light saturation point. The ecosystem respiration (Reco) increased with rising Ts, and was more sensitive to the Ts when the temperature was low (the Q10 of Lloyd-Taylor equation was 1.8 at 10 ℃), compared with that at high temperature (Q10 was 1.43 at 30 ℃). The VPD could act on CO2 exchange by affecting plant stomata conductance. When the VPD rose, both the CO2 release and the CO2 fixation increased. Precipitation had significant effect on the Reco through increasing soil moisture content. After precipitation, the Reco at 25 ℃ was 15.8% higher than that before precipitation. There was a wider green space in northeast and southwest directions around the observation station. When these directions were the main contribution areas, the absolute value of NEE was larger, indicating that increasing urban green space could improve urban carbon fixation effect.