Dissimilatory iron reduction contributes to anaerobic mineralization of sediment in a shallow transboundary lake  

作　　者：Yuxiang Yuan Cong Ding Haitao Wu Xue Tian Min Luo Weiyi Chang Lei Qin Liang Yang Yuanchun Zou Kaikai Dong Xiaoyan Zhu Ming Jiang Marinus L.Otte 

机构地区：[1]Key Laboratory of Wetland Ecology and Environment,Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China [2]Key Laboratory of Songliao Aquatic Environment,Ministry of Education,Jilin Jianzhu University,Changchun 130118,China [3]College of Environment and Safety Engineering,Fuzhou University,Fuzhou 350108,China [4]Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta,Binzhou University,Binzhou 256603,China [5]Wet Ecosystem Research Group,Biological Sciences,Department 2715,North Dakota State University,Fargo 58108-6050,United States

出　　处：《Fundamental Research》2023年第6期844-851,共8页自然科学基础研究（英文版）

基　　金：the Key Program of the National Natural Science Foundation of China(42230516);National Natural Science Foundation of China(42271129,42101071,42171107);Natural Science Foundation of Jilin Province(YDZJ202201ZYTS480);Jilin Province Education Department Science and Technology Research Project(JJKH20210289KJ);International Wetlands Research League,Alliance of International Science Organizations(ANSO-PA-2020-14).

摘　　要：Dissimilatory iron reduction(DIR)coupled with carbon cycling is increasingly being recognized as an influential process in freshwater wetland soils and sediments.The role of DIR in organic matter(OM)mineralization,however,is still largely unknown in lake sediment environments.In this study,we clarified rates and pathways of OM mineralization in two shallow lakes with seasonal hydrological connectivity and different eutrophic situations.We found that in comparison with the domination of DIR(55%)for OM mineralization in Lake Xiaoxingkai,the contribution of methanogenesis was much higher(68%)in its connected lake(Lake Xingkai).The differences in rates and pathways of sediment OM mineralization between the two lakes were attributed to higher concentrations of carbonate associated iron oxides(Fecarb)in Lake Xiaoxingkai compared to Lake Xingkai(P=0.002),due to better deposition mixing,more contributions of terrigenous detrital materials,and higher OM content in Lake Xiaoxingkai.Results of structural equation modeling showed that Fecarb and total iron content(TFe)regulated 25%of DIR in Lake Xiaoxingkai and 76%in Lake Xingkai,accompanied by a negative effect of TFe on methanogenesis in Lake Xingkai.The relative abundance and diversity of Fe-reducing bacteria were significantly different between the two lakes,and showed a weak effect on sediment OM mineralization.Our findings emphasize the role of iron minerals and geochemical characterizations in regulating rates and pathways of OM mineralization,and deepen the understanding of carbon cycling in lake sediments.

关 键 词：Dissimilatory iron reduction Organic matter mineralization Methane production Iron oxides Carbon cycling 

分 类 号：P59[天文地球—地球化学]