作 者：
张鑫磊;宋怡轩;张洁;汪方圆;张耀鸿;贾仲君
单 位：
南京信息工程大学气象灾害预报预警与评估协同创新中心/江苏省农业气象重点实验室;山西省气候中心;中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室
关键词：
围垦;稻田;产甲烷速率;H_2/CO_2营养型产甲烷菌
摘 要：
滨海湿地是CH_4排放的重要自然源,受人类活动的影响较为强烈。本研究选择长江入海口崇明东滩自然湿地(光滩湿地和芦苇湿地)为对照,以空间代替时间变化,比较研究不同围垦年限(27、51、86年)的稻田耕作土壤产甲烷速率演替规律及其微生物数量变异特征。结果表明,围垦稻田的产甲烷速率平均值为13.8 ng CH_4·g~(-1)·d~(-1),是自然滩涂湿地的3.3倍,且随着围垦年限增加而显著增加。围垦稻田中产甲烷菌的mcr A基因拷贝数为1.101×10~8～1.443×10~8copies·g~(-1),也随围垦年限增长而增加,比光滩湿地中的基因拷贝数高出一个数量级。光滩湿地产甲烷菌的相对丰度显著低于芦苇湿地和围垦稻田,围垦稻田中相对丰度值随围垦年限增长而显著增加。其中,H_2/CO_2营养型产甲烷菌的相对丰度随内陆方向和围垦年限增长而数量级水平增加,而甲基营养型产甲烷菌的相对丰度在光滩中最高,随内陆方向和围垦年限增长而数量级水平减小。各采样点中的乙酸营养型产甲烷菌相对丰度同处于一个数量级,其在3个围垦稻田中没有显著差异。相关性分析表明,产甲烷速率与H_2/CO_2营养型产甲烷菌丰度值呈显著正相关,而与甲基营养型产甲烷菌呈显著负相关。因此,围垦种稻的熟土作用促进了滨海湿地甲烷产生过程,H_2/CO_2营养型产甲烷菌数量的大幅增加是产甲烷速率升高的主控因素之一。
译 名：
Effects of reclamation and cultivating rice on CH_4-producing microorganisms in Chongming Dongtan Wetland,China
作 者：
ZHANG Xin-lei;SONG Yi-xuan;ZHANG Jie;WANG Fang-yuan;ZHANG Yao-hong;JIA Zhong-jun;Collaborative Innovation Center for Forecast and Evaluation of Meteorological Disasters/Jiangsu Provincial Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology;State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences;Shanxi Climate Center;
关键词：
reclamation;;paddy field;;CH_4 production potential;;H_2/CO_2 trophic methanogens
摘 要：
Coastal wetlands are an important natural source of CH_4 emission,which is strongly influenced by human activities.In this study,Chongming Dongtan Natural Wetland(bare,flat wetland and reed-vegetated wetland)in the estuary of Yangtze River was selected as the control,and CH_4 production potential and the related microbial quantity and characteristics were investigated in the paddy field soils with different reclamation years(27,51,86 years).The results showed that the average rate of CH_4 production in reclaimed paddy fields was13.8 ng CH_4·g~(-1)·d~(-1),which was 3.3 times higher than that in natural wetlands and increased significantly with the increase in reclamation years.The average copy number of mcr A gene in the methanogens was 1.101×10~8～1.443×10~8copies·g~(-1)in reclaimed paddy fields,which was an order of magnitude higher than that in bare,flat wetland and increased with the increase in reclamation years.The relative abundance of the methanogens(as a percentage of the whole archaea)was significantly lower in bare,flat wetland than in reed wetland and reclaimed paddy field,and the relative abundance in reclaimed paddy field increased significantly with the increase in reclamation years.More importantly,the relative abundance of H_2/CO_2 trophic methanogens increased in order of magnitude with the increase in reclamation years,whereas the relative abundance of methylamine trophic methanogens decreased in order of magnitude with the increase in reclamation years.In addition,the relative abundance of acetic acid trophic methanogens was in the same order of magnitude in the five sampling sites,and there was no significant difference among the three reclaimed paddy fields.The correlation analysis showed that the production rate of CH_4 was positively correlated with the abundance of H_2/CO_2 trophic methanogens,but negatively correlated with methylamine trophic methanogens.Therefore,mellowing the soil using reclamation and cultivating rice promote the production of CH_4 in coastal wetlands,and the significant increase in the number of H_2/CO_2 trophic methanogens is one of the main factors controlling the increased CH_4 production rate.
