文献类型：期刊文献

英文题名：Sediment Properties Strongly Drive Riverine Methane Emissions:A Case Study of the Liao River in Northern China

作者：Cui, Panpan[1] Cui, Lijuan[2] Zheng, Yunlong[1] Su, Fangli[1,3,4]

第一作者：Cui, Panpan

机构：[1] College of Water Conservancy, Shenyang Agricultural University, Shenyang, 110866, China; [2] Institute of Wetland Research, Chinese Academy of Forestry, Beijing, 100091, China; [3] Liaoning Panjin Wetland Ecosystem National Observation and Research Station, Shenyang, 110866, China; [4] Liaoning Shuangtai Estuary Wetland Ecosystem Research Station, Panjin, 124112, China

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240210829)

语种：英文

外文关键词：Biogeochemistry - Carbon - Carbon dioxide - Floods - Grain size and shape - Greenhouse gases - Metabolism - Methane - Rivers - Sediments - Watersheds

摘要：River and stream sediments serve as biogeochemical reactors of greenhouse gases, particularly methane. However, the understanding of source identification and process mechanisms of river carbon emissions is still relatively vague. The Liao River in northern China is a typical watershed with heterogeneous sources of water-sand and disparate sediment properties. In this paper, we conducted in situ surveys of CH4 and CO2 emissions from its mainstem and tributaries in flood and dry season. We found that the seasonal patterns of CH4 and CO2 emissions were consistent, with the peaks in flood season, and the average of CH4 and CO2 fluxes were 1636.04 ± 1803.75 μmol·m?2·d?1 and 59.66 ± 44.60 mmol·m?2·d?1 respectively. Importantly, sediment silt% were significantly correlated with CH4 concentration and flux (R2 = 0.12?0.30), and fine particles dominated the sediment organic matter availability and redox conditions related to riverine CH4 production and emissions. SEM demonstrated that both grain size and TOC% directly drove riverine CH4 and CO2 emissions, and riverbed sediment organic content and redox conditions together explained 65% of riverine CH4 emissions, grain size composition indirectly controlled CH4 emissions by altering sediment substrate quality and redox conditions. However, river CO2 emissions were weakly dependent on anaerobic metabolism of riverbed sediments. These findings expand our understanding of the sources and metabolic mechanisms of riverine CH4 and CO2 emissions, and offer the potential to improve carbon flux estimation in regional or global riverine networks with reference to riverbed sediment properties. ? 2024, The Authors. All rights reserved.