Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea(SCS)were measured to make a comparison during terrestrial vegetation reconstruction from~42 ka to~7 ka.The results showed that te...Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea(SCS)were measured to make a comparison during terrestrial vegetation reconstruction from~42 ka to~7 ka.The results showed that terrestrial vegetation record from long-chain n-alkanes matched well with previous studies in nearby cores,showing that more C_(4)plants developed during the Last Glacial Maximum(LGM)and C_(3)plants dominated in the interglacial period.However,these scenarios were not revealed by terrestrial vegetation reconstruction using long-chain n-alkanols,which showed C_(3)plant expansion during the LGM.The discrepancy during the interglacial period could be attributed to the aerobic degradation of functionalized long-chain n-alkanols in the oxygen-rich bottom water,resulting in poor preservation of terrestrial vegetation signals.On the other hand,the different advantages of functionalized n-alkanols and non-functional n-alkanes to record local and distal vegetation signals,respectively,may offer a potential explanation for the contradiction during the LGM when the SCS was characterized by low-oxygen deep water.Nevertheless,large variations on n-alkyl lipid compositions in C_(3)/C_(4)plants could play a part in modulating sedimentary long-chain n-alkanols and n-alkanes toward different vegetation signals,thereby suggesting that caution must be taken in respect to the terrestrial vegetation reconstruction using long-chain n-alkanes and long-chain n-alkanols.展开更多
基金The Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0104the Science and Technology Program of Guangzhou,China under contract No.201804010264+3 种基金the Guangdong MEPP Fund under contract No.GDOE[2019]A41the National Natural Science Foundation of China under contract No.41706059the Fund of Institution of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2020YB05the State Key R&D Project under contract No.2016YFA0601104。
文摘Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea(SCS)were measured to make a comparison during terrestrial vegetation reconstruction from~42 ka to~7 ka.The results showed that terrestrial vegetation record from long-chain n-alkanes matched well with previous studies in nearby cores,showing that more C_(4)plants developed during the Last Glacial Maximum(LGM)and C_(3)plants dominated in the interglacial period.However,these scenarios were not revealed by terrestrial vegetation reconstruction using long-chain n-alkanols,which showed C_(3)plant expansion during the LGM.The discrepancy during the interglacial period could be attributed to the aerobic degradation of functionalized long-chain n-alkanols in the oxygen-rich bottom water,resulting in poor preservation of terrestrial vegetation signals.On the other hand,the different advantages of functionalized n-alkanols and non-functional n-alkanes to record local and distal vegetation signals,respectively,may offer a potential explanation for the contradiction during the LGM when the SCS was characterized by low-oxygen deep water.Nevertheless,large variations on n-alkyl lipid compositions in C_(3)/C_(4)plants could play a part in modulating sedimentary long-chain n-alkanols and n-alkanes toward different vegetation signals,thereby suggesting that caution must be taken in respect to the terrestrial vegetation reconstruction using long-chain n-alkanes and long-chain n-alkanols.
