Highresolution Records of Lacustrine Sedimentology and Palynology Responding to Changes in Climate and Hydrology

Key words: 
• sedimentary pollen /
• riverlinked lake /
• precipitation changes /
• historical floods of Yangtze River /
• hundredyear processes /
• response to climate

Abstract: This paper studied highresolution sedimentary pollen sequence (1.5 yr/e) of Wanghu Lake, in the middle reach of Yangtze River, and analyzed the relationships of changes in pollen types and contents, sediment granularity, and climatehydrology features during the past hundred years when the lake turned from an open water system into closed basin. Correlation analysis for time series of pollen, granularity, catchment precipitation and river discharge, showed that significant linear relationships with 95% confidence level. Major pollen types showed a 27%40% synchronous changes with time series of granularity and precipitation during the past 130 years, and a 47%57% synchronous changes with time series of granularity and river discharge before the mid1960's when the lake naturally connected with Yangtze River, suggesting pollen deposition controlled by sediments and catchment precipitation. The author found synchronous changes among sedimentary granularity and pollen with precipitation and river discharge which all experienced 34 years and 911 years cycles in the time series, suggesting sedimentation responding to climate changes. This study may provide scientific basis to reconstruct past environmental changes using sediment and pollen records, and to understand biosedimentology dynamics in the lake sediments. 