The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We re...The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We report marine biomarker records of brassicasterol,dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea(SYS)to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene.The contents of the corresponding biomarkers in the two cores are similar,and they also reveal broadly similar temporal trends.From 6 kyr to 3 kyr,the biomarker contents in the two cores were relatively low with small oscillations,followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM.The alkenone/brassicasterol ratio(A/B)is used as a community structure proxy,which also showed higher values in both cores since 3 kyr,indicating increased haptophyte contribution to total productivity.It is proposed that the YS community structure has been mainly influenced by the YSWC,with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr.Some differences of the biomarker records between ZY2 and ZY1 suggest spatial variations in response to YSWC and KC forcing.When the KC was intensified during the periods of 6 4.2 kyr and 1.7 0 kyr,the YSWC extended eastward,exerting more influence on core ZY1.On the other hand,when the KC weakened during 4.2 1.7 kyr,the YSWC extended westward,exerting more influence on the ZY2.展开更多
基金supported by the National Basic Research Program of China(973 Program 2010CB428901)the National Natural Science Foundation of China(Grant Nos.41221004,41020164005)the ‘111’ Project
文摘The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We report marine biomarker records of brassicasterol,dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea(SYS)to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene.The contents of the corresponding biomarkers in the two cores are similar,and they also reveal broadly similar temporal trends.From 6 kyr to 3 kyr,the biomarker contents in the two cores were relatively low with small oscillations,followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM.The alkenone/brassicasterol ratio(A/B)is used as a community structure proxy,which also showed higher values in both cores since 3 kyr,indicating increased haptophyte contribution to total productivity.It is proposed that the YS community structure has been mainly influenced by the YSWC,with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr.Some differences of the biomarker records between ZY2 and ZY1 suggest spatial variations in response to YSWC and KC forcing.When the KC was intensified during the periods of 6 4.2 kyr and 1.7 0 kyr,the YSWC extended eastward,exerting more influence on core ZY1.On the other hand,when the KC weakened during 4.2 1.7 kyr,the YSWC extended westward,exerting more influence on the ZY2.
