Biogeochemistry of sedimentary organic matter in the Yongjiang River estuary in the southern part of Hangzhou Bay,China,since the Late Pleistocene  

作　　者：Dongqin HUANG Xiaolong LI Zilong LI Pei Sun LOH Jianxiong HU Jianfang CHEN Yuan-Pin CHANG Chin-Wen YANG Qin GAO 

机构地区：[1]Institute of Marine Geology and Resources,Ocean College,Zhejiang University,Zhoushan 316021,China [2]Ministry of Water Resources of the People’s Republic of China,Beijing 100054,China [3]Key Laboratory of Marine Ecosystem Dynamics,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China [4]Department of Oceanography,Sun Yat-sen University,Kaohsiung 80424,China

出　　处：《Journal of Oceanology and Limnology》2024年第3期772-786,共15页海洋湖沼学报（英文）

基　　金：Supported by the China Institute of Water Resources and Hydropower Research(No.K20231586);the Water Conservancy Bureau of Yunyang County(No.YYX24C00008);the Ecological Forestry Development Center of Lishui City(No.2021ZDZX03);the Asia-Pacific Network for Global Change Research(No.CRRP2020-06MY-Loh)。

摘　　要：A sediment core(YJK19-02)collected from the southern outlet of Hangzhou Bay near the Yongjiang River estuary in East China was analyzed for grain size,lignin,bulk elemental composition,stable carbon isotope,and rare earth elements(REEs)to determine the sources and diagenesis of sedimentary organic matter(OM)of the estuary and adjacent areas since the Late Pleistocene.δ^(13)C values(-24.80‰–-23.60‰),total organic carbon/total nitrogen(TOC/TN)molar ratios(8.00–12.14),and light rare earth element/heavy rare earth element ratios(LREE/HREE=8.34–8.91)revealed the predominance of terrestrial sources of OM,mainly from the Changjiang(Yangtze)River.The lignin parameters of syringyl/vanillyl(S/V=0.20–0.73)and cinnamyl/vanillyl(C/V=0.03–0.19)ratios indicate the predominance of nonwoody angiosperms,and the vanillic acid/vanillin ratios[(Ad/Al)_(V)=0.32–1.57]indicate medium to high degrees of lignin degradation.An increasing trend ofΛ(total lignin in mg/100-mg OC)values from ca.14500 a BP to ca.11000 a BP reflected the increase in temperature during the Late Pleistocene.However,a time lag effect of temperature on vegetation abundance was also revealed.The relatively higher and stableΛvalues correspond to the higher temperature during the mid-Holocene from ca.8500 a BP to ca.4500 a BP.Λvalues decreased from ca.4000 a BP to the present,corresponding to historical temperature fluctuations during this time.Our results show that the vegetation abundance in the Yongjiang River Basin since the Late Pleistocene was related to the temperature fluctuation duo to climate change.

关 键 词：Yongjiang River estuary sedimentary organic matter LIGNIN environmental change Late Pleistocene 

分 类 号：P534.631[天文地球—第四纪地质学] P512.2[天文地球—古生物学与地层学] P593[天文地球—地质学]