Floating plants reduced methane fluxes from wetlands by creating a habitat conducive to methane oxidation  

作　　者：Fuwei Wang Songhe Zhang Xiuren Hu Xin Lv Min Liu Yu Ma Benjamin Manirakiza 

机构地区：[1]Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes,Ministry of Education,Hohai University,Nanjing 210098,China [2]College of Environment,Hohai University,Nanjing 210098,China [3]China Machinery International Engineering Desigh and Research Institute co.,Ltd.East China Regional Center,Nanjing 210008,China

出　　处：《Journal of Environmental Sciences》2024年第1期149-160,共12页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 51879084);the Technology Program for Water Pollution Control and Treatment of China (No. 2018ZX07208-004)。

摘　　要：Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane release.However,the effects of floating plants on methane release are limited.In this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa natans.We found that E.crassipes,H.dubia,and T.natans plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,respectively.Methane fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and leaves.At the same biomass,root of E.crassipes (36.44%) had the highest methane oxidation potential,followed by H.dubia (12.99%) and T.natans (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known methanotrophs.Type I methanotrophs accounted for 95.07%of total methanotrophs.The pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root biofilms.Abundances of pmoA gene was significantly positively correlated with environmental parameters.Methylotrophy (5.40%) and methanotrophy (3.75%) function were closely related to methane oxidation.This study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.

关 键 词：Floating plants Methane fluxes AERENCHYMA METHANOTROPHS 

分 类 号：X173[环境科学与工程—环境科学] X143