Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds  

作　　者：CHEN Xin JIN Jing NIE Yaguang ZHANG Jifeng DONG Liang HUANG Xianyu Steven D()EMSLIE LIU Xiaodong 

机构地区：[1]Anhui Province Key Laboratory of Polar Environment and Global Change,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [2]School of Oceanography,Shanghai Jiao Tong University,Shanghai 200030,China [3]Key Laboratory for Polar Ecosystem and Climate Change of Ministry of Education,School of Oceanography,Shanghai Jiao Tong University,Shanghai 200030,China [4]Information Materials and Intelligent Sensing Laboratory of Anhui Province,Institutes of Physical Science and Information Technology,Anhui University,Hefei 230601,China [5]Research Center for Ecology,College of Science,Tibet University,Lhasa 850000,China [6]Key Laboratory of Polar Science,MNR,Polar Research Institute of China,Shanghai 200136,China [7]Hubei Key Laboratory of Critical Zone Evolution,School of Geography and Information Engineering,China University of Geosciences,Wuhan 430078,China [8]Department of Biology and Marine Biology,University of North Carolina,Wilmington,NC 28403,USA

出　　处：《Advances in Polar Science》2023年第4期304-317,共14页极地科学进展（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant nos. 42276240, 42206243, 41776188);the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant no. XDB40000000);the Shanghai Sailing Program (Grant no. 22YF1418800);the China Postdoctoral Science Foundation (Grant no. 2022M712038);the Shanghai Frontiers Science Center of Polar Science (SCOPS);the Chinese Arctic and Antarctic Administration (CAA) for supporting the project

摘　　要：Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core(IIL3)to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea,Antarctica.Short-chain n-alkanoic acids(C14–C18)were abundant in the IIL3 sediment profile.The carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar,indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic organisms.Theδ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile,and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic efficiency.Theδ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity(n-alkanoic acid and sterol sedimentary fluxes).C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity~150–600 and 2500–3000 a BP.The results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes.

关 键 词：East Antarctica lipid biomarkers carbon isotopic ratios pond primary productivity climate change 

分 类 号：P941.61[天文地球—自然地理学] P532P597