Knowledge of quantitative palaeoclimates is a crucial for the evaluation of climate changes for the earth system.Previous quantitative palaeoclimate reconstruction in China generally used the modern statistic methods between pollen and climate data.The reconstruction methods are built upon the assumption that plant-climate interactions remain the same through time,and implicitly assume that these interactions are independent of changes in the seasonal climate and the atmospheric CO_2.This assumption may lead to a considerable bias.In this study,an improved inverse vegetation model that based on a physiological process has been designed to quantitatively reconstruct past climates,with a new China Quaternary Pollen Database.During the mid-Holocene period,mean annual temperature in China were higher ca.0.7℃ than present,especially in the Eastern China,but cooler in the northwest China.Winter temperature were generally higher ca.1.0℃ than today,but summer temperature only higher ca.0.5℃ than present.Mean annual precipitation were wetter ca.230mm than today,especially in the Eastern China,which was due to the increase of summer rainfall.Our results suggest that the precipitation maybe increase,while the seasonal temperature variation became significant with the global temperature warming.The new reconstructions therefore give a better agreement with PMIP simulations.
1.中国科学院地质与地球物理研究所, 中国科学院新生代地质与环境重点实验室, 北京 100029, 中国 2.中国科学院大学, 北京 100049, 中国 3.中国科学院植物研究所, 北京 100093, 中国 4.Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing 100029, China