Re-estimating China's lake CO_(2)flux considering spatiotemporal variability  

作　　者：Zhidan Wen Yingxin Shang Lili Lyu Hui Tao Ge Liu Chong Fang Sijia Li Kaishan Song 

机构地区：[1]Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun,130102,China [2]School of Environment and Planning,Liaocheng University,Liaocheng,252000,China

出　　处：《Environmental Science and Ecotechnology》2024年第3期152-160,共9页环境科学与生态技术（英文）

基　　金：supported by the Natural Science Foundation of Jilin Province,China(grant no.20220203024SF);the Youth Innovation Promotion Association of Chinese Academy of Sciences,China(grant no.2020234);the National Natural Science Foundation of China(grant no.42071336,U2243230,42371390,42101336);Young Scientist Group Project of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(grant no.2023QNXZ01);Science and technology innovation cooperation project,Changchun,China(grant no.21SH10);the National Earth System Science Data Center,China(www.geodata.cn).

摘　　要：The spatiotemporal variability of lake partial carbon dioxide pressure(pCO_(2))introduces uncertainty into CO_(2)fluxestimates at the lakewater-air interface.Knowing the variationpattern of pCO_(2)isimportant for obtaining accurate global estimation.Here we examine seasonal and trophic variations in lake pCO_(2)based on 13 field campaigns conducted in Chinese lakes from 2017 to 2021.We found significant seasonal fluctuations in pCO_(2),with decreasing values as trophic states intensify within the same region.Saline lakes exhibit lower pCO_(2)levels thanfreshwater lakes.These pCO_(2)dynamics result invariable areal CO_(2)emissions,withlakes exhibiting different trophic states(oligotrophication>mesotrophication>eutrophication)and saline lakes differing from freshwater lakes(-23.1±17.4 vs.19.3±18.3 mmol m^(-2)d^(-1)).These spatiotemporal pCO_(2)variations complicate total CO_(2)emission estimations.Using area proportions of lakes with varying trophic states and salinity in China,we estimate China's lake CO_(2)flux at 8.07 Tg C yr^(-1).In future studies,the importance of accounting for lake salinity,seasonal dynamics,and trophic statesmust be noticed to enhance the accuracy of large-scale carbon emission estimates from lake ecosystems in the context of climate change.

关 键 词：Carbon dioxide EUTROPHICATION Saline lakes OVERESTIMATION Carbon budget 

分 类 号：X524[环境科学与工程—环境工程]