崇明岛地区6500年以来植被、气候演化

Evolution of Vegetation and Climate in the past 6500 Years on Chongming Island

崇明岛地区以前孢粉研究资料较少 ,通过对崇明岛北侧的CY孔作了高分辨率的孢粉研究 ,详细地划出了大西洋期以来的 9个孢粉组合带 ,并结合邻区钻孔孢粉资料研究 ,恢复了该区植被、气候演化的 7个阶段 .从大西洋中期起植被依次为 :中亚热带含落叶树的常绿阔叶林—中亚热带北缘常绿阔叶、落叶阔叶混交林—北亚热带北缘以松、栎为主的落叶阔叶、针叶混交林—中亚热带北缘常绿阔叶、落叶阔叶混交林—北亚热带常绿阔叶、落叶阔叶、针叶混交林—北亚热带北缘含常绿阔叶树的落叶阔叶、针叶混交林—北亚热带常绿阔叶、落叶阔叶、针叶混交林 .气候经历如下的波动 :热暖潮湿—暖热湿润—温和略干—温暖湿润—温暖略湿—温而略干—温暖湿润 ,这种气候的波动与世界性的气候变化相一致 ,而且与海平面变化相吻合 ,从而为该地区古植被、古气候。

According to the high-resolution sporopollen researc h about core CY exiting in the north of Chongming Island,nine sporopollen assembla ges have been distinguished since the Atlantic period.Combined with the sporopol len research about the core of adjacent areas,seven stages about the evolution o f the vegetation and climate in this area were reconstructed.Since the middle pe riod of the Atlantic period,the vegetation stages were:① evergreen broad-leave s forest including deciduous trees in the middle sub-tropic;② mixed forest of evergreen broad-leaves forest and deciduous broad-leaves forest in the north e dge of the middle sub-tropic;③ mixed forest of deciduous broad-leaves trees a nd conifer trees mainly including Pinus and Quercus in the north edge of nor th sub-tropic;④ mixed forest of evergreen broad-leaves and deciduous broad-l eaves forest in the north of middle sub-tropic;⑤ mixed forest of evergreen bro ad-leaves,deciduous broad-leaves and conifer forest in the north sub-tropic; ⑥ mixed forest of deciduous broad-leaves and conifer forest including evergree n broad-leaves trees in the north edge of north sub-tropic;⑦ mixed forest of evergreen broad-leaves,deciduous broad-leaves and conifer forest in the north sub-tropic.The fluctuation of the climate was as below:hot-warm and mois t→warm and moist→temperate and a little dry→warm and moist→warm and a little moist→temperate and little dry→warm and moist.Such fluctuation of the climate is not only accord with the changes of the world climate,but also the changes of the sea level,providing reliable information for reconstruction of plaeovegetat ion,plaeoclimate and plaeoenvironment.