文献类型：期刊文献

英文题名：The significant contribution of lake depth in regulating global lake diffusive methane emissions

作者：Li, Mingxu[1,2,3] Peng, Changhui[1,3] Zhu, Qiuan[1] Zhou, Xiaolu[1] Yang, Gang[4] Song, Xinzhang[5] Zhang, Kerou[6]

第一作者：Li, Mingxu

通信作者：Peng, CH[1]

机构：[1]Northwest A&F Univ, Coll Forestry, Ctr Ecol Forecasting & Global Change, Yangling 712100, Shaanxi, Peoples R China;[2]Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China;[3]Univ Quebec Montreal, Inst Environm Sci, Dept Biol Sci, CP 8888, Montreal, PQ H3C 3P8, Canada;[4]Southwest Univ Sci & Technol, Sch Life Sci & Engn, Mianyang 621010, Sichuan, Peoples R China;[5]Zhejiang A&F Univ, Nurturing Stn, State Key Lab Subtrop Silviculture, Linan 311300, Peoples R China;[6]Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China

年份：2020

卷号：172

外文期刊名：WATER RESEARCH

收录：;EI(收录号：20200308057757);Scopus(收录号：2-s2.0-85077975208);WOS:【SCI-EXPANDED(收录号:WOS:000517663600023)】；

基金：This study was funded by the National Key R&D Program of China (2016YFC0500203), China, the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada, the National Natural Science Foundation of China (31988102) and the Chinese Academy of Sciences Strategic Priority Research Program (XDA23080401).

语种：英文

外文关键词：Global methane estimation; Lake CH4 diffusion; Maximum depth; Surface area; Freshwaters GHGs emissions

摘要：Global lakes have been identified as an important component of natural methane (CH4) sources. Given that lake CH4 emissions involve multiple, complex processes influenced by various environmental factors, estimates of global lake CH4 emissions are largely uncertain. In this study, we compiled global CH4 emission data on 744 lakes from published studies, and found a significantly negative correlation (R-2 = 0.50, p < 0.01) between diffusive CH4 flux and lake maximum depth. Further analysis indicated that no significant differences in global sediment CH4 production were found for the different maximum depths investigated. Owing to the longer oxidation pathway, presence of oxycline layer, and the lower nutrient environment, deeper lakes yield less diffusive CH4 efflux compared to shallower lakes. Additionally, we also found that lake area was negatively correlated (R-2 = 0.13, p < 0.01) to diffusive CH4 flux. Therefore, based on empirical correlations between lake morphometry (maximum depth and area) and diffusive CH4 emission, as well as the combination of two lake databases, we estimated that the annual diffusive CH4 emission from global lakes is approximately 11.2 (6.2-19.5) Tg CH4/yr, and greater than 84% is emitted from lakes with a mean depth of less than 5 m. Furthermore, two regions, 40-70 degrees N (30.4%) and 20 degrees S similar to 10 degrees N (37.4%), were found to be the dominant contributors of global lake diffusive CH4 emissions, resulting from the considerable total lake area and the extensive shallow lakes in these regions. This study highlights the significance of the 'depth-effect' which controls the spatial distribution of lake diffusive CH4 flux and allows for the quantification of global lake diffusive CH4 emissions. (C) 2020 Elsevier Ltd. All rights reserved.