Supported by the National Key Research and Development Program of China (No. 2017YFD0300105), the National Natural Science Foundation of China (No. 41877325) and the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2018349)
大气CO2浓度升高可直接或间接影响稻田CH4排放。深入研究长期大气CO2浓度升高对稻田CH4排放及其相关微生物的影响，对评估和应对未来气候背景下稻田CH4排放的响应具有重要意义。为探明长期大气CO2浓度升高对稻田CH4排放的影响及其机制，依托连续运行10年以上的中国稻田FACE（free-air CO2 enrichment）平台，观测2016—2017年正常大气条件（ACO2）和大气CO2浓度升高200µmol·mol–1条件（ECO2）下稻田CH4排放通量、产甲烷菌和甲烷氧化菌群落丰度，并采用Meta分析方法定量研究CO2熏蒸年限对稻田CH4排放及其相关微生物群落丰度的影响。结果表明：对比ACO2处理，长期ECO2处理使稻田CH4排放降低28%（P<0.05），产甲烷菌群落丰度降低39%（P<0.05），同时甲烷氧化菌群落丰度增加21%（P>0.05）。Meta分析结果发现，随着CO2熏蒸年限的增加，大气CO2浓度升高对稻田CH4排放和产甲烷菌群落丰度的促进作用逐渐减弱，对甲烷氧化菌群落丰度的促进作用却逐渐增大。因此，未来气候条件下，长期大气CO2浓度升高会降低稻田CH4排放，这对缓解水稻种植带来的温室效应具有重要意义。
[Objective] Increases in atmospheric CO2 concentration have certain direct or indirect impacts on CH4 emission from rice paddy fields. So it is of great significance to have an in-depth study on impacts of long-term elevated atmospheric CO2 concentration on CH4 emission and related microorganisms for assessing and managing CH4 emissions from rice paddy fields in the context of future climate.[Method] To investigate effects of long-term elevated atmospheric CO2 concentration on CH4 emission and its mechanism, CH4 emission fluxes and abundance of the methanogens and methanotrophs under ambient CO2 (ACO2) and elevated CO2 conditions (ECO2) in rice paddy fields were monitored during the 2016-2017 season, with the aid of the Chinese rice FACE platform that has been operating for more than 10 years. Moreover, meta-analysis was conducted to determine quantitatively effects of elevated CO2 relative to duration on CH4 emission from and the abundances of methanogens and methanotrophs in rice paddy fields.[Result] Results show that compared with ACO2, long-term ECO2 significantly reduced CH4 emission and the abundance of methanogens by 28% and 39%, respectively (P<0.05), but increased the abundance of methanotrophs by 21% (P>0.05). Meta-analysis shows that with the increase in duration of CO2 elevation, the effect of elevated atmospheric CO2 concentration promoting CH4 emission and the abundance of methanogens gradually decreased, while the effect on the abundance of methanotrophs gradually increased.[Conclusion] Therefore, it could be concluded that under future climate conditions, long-term elevated CO2 will reduce CH4 emission from rice fields, which is of great significance for mitigating the greenhouse effect brought about by rice cultivation.
于海洋,王天宇,黄琼,张广斌,马静,朱春梧,徐华.长期大气CO2浓度升高对稻田CH4排放的影响[J].土壤学报,2022,59(4):1057-1067. DOI:10.11766/trxb202009110515 YU Haiyang, WANG Tianyu, HUANG Qiong, ZHANG Guangbin, MA Jing, ZHU Chunwu, XU Hua. Effect of Long-term Elevated CO2 Concentration on CH4 Emissions from Rice Paddy Fields[J]. Acta Pedologica Sinica,2022,59(4):1057-1067.复制