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

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.