依据南黄海DLC70-3孔71.2m长沉积序列的孢粉记录,结合测年数据,有孔虫和粒度等环境指标,恢复了研究区晚更新世以来的古环境变化。钻孔孢粉组合可以反演南黄海陆缘区植被面貌,其中草本花粉在整个剖面占绝对优势,具有超代表性,而木本花粉代表性低。除冰盛期沉积缺失之外,孢粉等指标在MIS5阶段以来变化显著:MIS5和MIS3的亚间冰阶及MIS2/1(冰消期)阶段,阔叶树种和蒿属比例较高,沟鞭藻、有孔虫含量也较高,气候偏暖,属沉积动力相对稳定的浅海或滨海环境;而MIS5及MIS3阶段的亚冰阶和MIS4阶段,针叶组分或冷杉含量增加,中生-水生草本含量相对较高,而有孔虫含量极低或消失,气候偏冷,属沉积动力相对复杂的滨岸湖泊或沼泽等陆相环境。同时,对比周边地区其他孢粉记录,结果表明,在冰期-间冰期旋回过程中孢粉组合中针叶-阔叶组分含量此消彼长,草本含量的相对变化可指示滨岸局域植被的演替,且一定程度上可以反映海平面的升降。
Pollen analysis was carried out for the 71.2mlong core DLC70-3in the South Yellow Sea(SYS).Together with dating data,foraminifera and grain size proxies,the long pollen record reveals the paleoenvironmental changes in the study area since the late Pleistocene.Pollen assemblages could reflect the vegetation landscape along the continental margin of SYS,and the whole sequence was dominated by herbaceous pollens of over-presentation,while woody pollen was of low-presentation.Except for the sedimentary hiatus during the glacial maximum,pollen assemblages and other indicators of DLC70-3core varied significantly since the MIS5period:The characteristics of pollen assemblages were similar in the subinterglacial stages of MIS5 and MIS3and in MIS2/1periods,with high abundance of deciduous and evergreen trees,Artemisia,Dinoflagellate and foraminifera,indicating a relatively warm climate in the littoral or shallow sea environment of a relatively stable sedimentary dynamics;However,pollen assemblages were consistent in sub-glacial stages of MIS5 and MIS3and in MIS4 periods,characterized by the increase in conifers or Abies,relatively high content of mesophytic and aquatic herbs,but low concentration or even disappearance of foraminifera,implying a relatively cold climate in the coastal lakes or marshes with complex depositional environments.Meanwhile,comparison with other palynological results from the Bohai Sea and South Yellow Sea areas shows that content of conifers and broadleaved trees fluctuated during the glacial-interglacial cycles,and variation of herbs could indicate the vegetation evolution in the local coastal areas and reflect the sea level changes to a certain extent.