中国主要河口淡水和咸水芦苇湿地CH_(4)和CO_(2)产生速率及影响因子  

Production rates and key influencing factors of CH_(4)and CO_(2)of freshwater and saltwater Phragmites australis marshes in major estuaries of China

作　　者：冯智桦 胡芳 展鹏飞 黄佳芳 仝川 FENG Zhi-hua;HU Fang;ZHAN Peng-fei;HUANG Jia-fang;TONG Chuan(Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China;Wetland Ecosystem Research Station of Minjiang Estuary,National Forestry and Grassland Administration,Fuzhou 350215,China)

机构地区：[1]福建师范大学地理科学学院,湿润亚热带生态-地理过程教育部重点实验室,福建福州350117 [2]福建闽江河口湿地生态系统国家定位观测研究站(国家林草局),福建福州350215

出　　处：《中国环境科学》2025年第4期2240-2250,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(42177213);国家重点研发计划项目(2022YFC3105401);中央专项财政支持项目([350182]FJYHZB[GK]2024001)。

摘　　要：采集辽河口、黄河口、长江口、瓯江口、闽江口、珠江口6个河口分布的淡水(盐度:0)和咸水(盐度:10~15)芦苇湿地的表层土样,室内运用泥浆厌氧培养法测定土壤CH_(4)、CO_(2)产生速率,并测定土壤胞外酶活性以及产甲烷菌功能基因(mcr A)丰度.6个河口淡水和咸水芦苇湿地土壤CH_(4)产生速率平均值分别为(2.69±1.63)和(2.97±1.71)ng CH_(4)/(g·d);CO_(2)产生速率平均值分别为(7.64±4.94)和(10.28±6.84)μg CO_(2)/(g·d).淡水芦苇湿地土壤CO_(2)产生速率显著低于咸水芦苇湿地,然而,淡水芦苇湿地土壤CH_(4)产生速率与咸水芦苇湿地无显著差异.土壤p H值、有机碳(SOC)含量是影响芦苇湿地土壤胞外酶活性以及产甲烷菌功能基因(mcr A)丰度的主要因子.土壤p H值、TC、TN、SOC以及5种胞外酶活性、产甲烷菌功能基因丰度是CH_(4)和CO_(2)产生的主要影响因子,p H值降低导致CH_(4)与CO_(2)产生速率显著下降,.本研究结果表明:中国沿海主要河口尺度淡水到中咸水生境,盐度不是芦苇湿地土壤CH_(4)产生速率的调控因子,但是盐度增加显著提升芦苇湿地土壤厌氧矿化速率,上述结果表明:,海平面上升-盐水入侵将导致河口区芦苇湿地土壤碳排放量增加.This study collected the surface soil samples(0~10cm)from the freshwater(salinity:0)and mesohaline(salinity:10~15)P.australis marshes in the six main estuaries in China,which are the Liao River Estuary,Yellow River Estuary,Yangtze River Estuary,Oujiang River Estuary,Minjiang River Estuary,and Pearl River Estuary.The production rates of soil CH_(4)and CO_(2)were measured using laboratory anaerobic slurry incubation method,and the extracellular enzyme activity and abundance of methanogen functional genes(mcrA)were also measured.Mean CH_(4)production rate in the freshwater and saltwater P.australis marshes was(2.69±1.63)and(2.97±1.71)ng CH_(4)/(g·d),respectively.Mean CO_(2)production rate was(7.64±4.94)and(10.28±6.84)μg CO_(2)/(g·d),respectively.CO_(2)production rate in the freshwater P.australis marshes was significantly lower than that in mesohaline P.australis marshes,but no significant difference in CH_(4)production rate was observed between freshwater and mesohaline marshes.Soil pH and soil organic carbon(SOC)content were identified as the main factors influencing extracellular enzyme activity and methanogen abundance.A decrease in pH led to a significant reduction in the production rates of CH_(4)and CO_(2).Total carbon,total nitrogen,SOC,activity of five extracellular enzymes,and abundance of mcrA were identified as the key factors influencing CH_(4)and CO_(2)production.Our research results suggest that across the Chinese coastal estuarine freshwater and mesohaline P.australis marshes,salinity is not a main factor controlling CH_(4)production,however,the increase in salinity perhaps raise soil anaerobic mineralization rates,which indicates that sea level rise and saltwater intrusion will cause carbon emission increase from estuarine P.australis marshes.

关 键 词：甲烷产生速率 二氧化碳产生速率 胞外酶 盐度 芦苇沼泽 河口 中国 

分 类 号：X511[环境科学与工程—环境工程]