摘 要 ：稻田水体中细菌（尤其是其中的大肠菌群）数量的多少及活性深刻影响着水体质量和物质循环，然而大气CO2浓度升高对它们的影响至今鲜有报道。为此，借助国际上唯一的稻麦复种FACE（free air CO2 enrichment）试验(位于江苏省江都市，始于2004年)，于2006年对稻田水体中细菌数量、大肠菌群数量、总有机碳量和总氮量等进行了动态监测。结果表明，大气 CO2浓度升高显著提高了以上各指标在稻田水体中的含量（P <0.01），在整个水稻生育期，与对照相比，水体中的细菌数量、大肠菌群数量、总有机碳量和总氮量平均分别提高了45.9%、68.8%、31.2%和25.9%，不同生育期之间上述各指标存在显著差异（P < 0.01）。可见，大气CO2浓度升高不仅可通过改变稻田水体质量的方式来影响水稻的安全生产，而且还可能通过田间排水尤其是水稻生长前期的暴雨导致的洪涝来加重稻田生态系统向周边居民井水和其它水域的细菌和大肠菌群的输出量，从而可能影响周边水体质量及人体健康。
Abstract:The quantity of the bacteria, especially the coliform group, in paddy water influenced the water quality and the matter circulation. However, there were few reports on that，especially under CO2 elevated condition. Therefore, by the aid of the internationally exclusive Free Air CO2 Enrichment of the rice-wheat sequential cropping system (started in 2004, located in Jiangdu county, Jiangsu province), this research did dynamic monitor on the population sizes of the bacteria and the coliform group, the concentrations of the total organic carbon (TOC) and the total nitrogen (TN) in paddy field water. The results showed that elevated atmospheric CO2 significantly increased the population sizes of the bacteria and the coliform group, as well as the concentrations of TOC and TN (P<0.01). Compared to the ambient plot, bacteria, coliform group, TOC and TN were respectively enhanced by 45.9%、68.8%、31.2% and 25.9% on average in FACE plot. There were significantly differences in bacteria population size, coliform group population size, water TOC and water TN between different rice growing stages (P<0.01). Those results demonstrate that atmospheric CO2 enrichment may aggravate the export of coliform group and bacteria from the paddy ecosystem to the surrounding wells and rivers through field drainage and rainstorms at the early stage of rice. Therefore elevated atmospheric CO2 may influence the rice security production and threaten human health.