中国南部OIS 5e时期中亚热带北移的古生物学证据

PALEONTOLOGICAL EVIDENCE FOR THE NORTH MOVEMENT OF MID-SUBTROPICAL DURING THE OIS 5e PERIOD IN SOUTHERN CHINA

大熊猫-剑齿象动物群是中国南方地区第四纪的代表性哺乳动物群,常见种属多见于亚热带地区,少数种属在自然状态下主要分布于热带-南亚热带地区,如猩猩、长臂猿、亚洲象和绝灭种巨貘、中国犀的现生种貘、犀等热带种,它们的存在指示了具热带气候性质的中亚热带南部的森林环境.本文在确定中国南部OIS 5e时期此类动物群种属构成与分布特征的基础上,主要以热带种属的分布及其北界为依据,推断出中业热带北界分布至秦岭-淮河以南,较现今北移约3°,1月份平均温较今高约4～5℃,年均温高约3℃,说明在现今的亚热带地区盛行中亚热带-热带的气候环境,发生了较大的生物-气候带变迁.该变迁事件对应于全球气候变化的高温期和35°N冬半年天文辐射总量的峰值,是全球气候变化影响下的结果.

The Ailuropoda-Stegodon fauna is a typical mammalian fauna in South China during the Quaternary.The common species mainly live in the subtropical zone, but some tropical species mainly distribute in tropical zone to south-subtropical zone, such as Pongo, Hylobates, Elephas maximus, as well as living species of Megatapirus augustus and Rhinoceros sinensis, indicating a forest environment with the south of mid-subtropical climate features.Based on the determination of faunal composition and geographic distribution characteristics during the OIS 5e in South China, we mainly depend on the distribution of tropical species and their far-north living boundary, and inferred that the north boundary of the mid-subtropical zone stays to the south of Qinling-Huaihe line of China, namely, it is three latitudes further northwards than today, and the temperature is about 4~5℃ higher than today in January, and annual temperature is 3℃ higher than average temperate.It suggests that the mid-subtropical climate or tropical climate possibly prevails at present subtropical zone, which indicates the great evolution of bioclimatic belt.The occurred event corresponds to the high temperature period and the peak of Solar radiation at 35°N in the winter-half year, which probably result from the global climate changes.