成都平原4000aBP以来的孢粉记录与环境变化

SPORE-POLLEN ASSEMBLAGE AND ENVIRONMENTAL CHANGES OF THE CHENGDU PLAIN DURING THE LATE HOLOCENE

成都平原晚全新世以来沉积的泥质层发现丰富的孢粉。根据孢粉成分组合特征和生态类型可划分出5个孢粉组合带,结合剖面上6个14C测年数据,提出在过去的4000a研究区植被类型及气候环境经历了5个阶段的变化:3800—3600aBP为亚热带常绿阔叶林,气候暖偏湿;3600—3400aBP为含常绿树种的落叶阔叶林,气候温暖湿润;3400—2600aBP为草/湿地,气温下降,环境更潮湿;2600—900aBP为落叶阔叶林,温度又开始逐渐回升,气候温和偏湿;900—300aBP再次变为草/湿地,偏干冷的气候环境。

On the Chengdu Plain, a four-meter thick sedtary succession has accumulated during the past 4 000a of Holocene. In this study, 82 samples were collected at 5cm intervals. Based on the characteristics of spore-pollen and 6 datasets from 14^C analysis, the vegetation-climatic changes on the Chengdu Plain during the last 4 000a are discussed. Five phases of paleovegetation successions and climatic fluctuations are revealed for the past 4 000 years, and five climate periods can be recognized and correlated regionally and globally. The results of this study suggest that the climate on Chengdu Plain has been affected by global climate to a certain degree.