A distinctive Eocene Asian monsoon and modern biodiversity resulted from the rise of eastern Tibet  

青藏高原东部隆升启动了始新世独特亚洲季风系统和生物多样性现代化

作　　者：Songlin He Lin Ding Zhongyu Xiong Robert A.Spicer Alex Farnsworth Paul J.Valdes Chao Wang Fulong Cai Houqi Wang Yong Sun Deng Zeng Jing Xie Yahui Yue Chenyuan Zhao Peiping Song Chen Wu 何松林;丁林;熊中玉;Robert A.Spicer;Alex Farnsworth;Paul J.Valdes;王超;蔡福龙;王厚起;孙永;曾登;谢静;岳雅慧;赵晨圆;宋培平;吴晨(State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESER),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,China;School of Environment,Earth and Ecosystem Sciences,the Open University,Milton Keynes MK76AA,UK;School of Geographical Sciences,University of Bristol,Bristol BS81SS,UK)

机构地区：[1]State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESER),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Tropical Forest Ecology,Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,China [4]School of Environment,Earth and Ecosystem Sciences,the Open University,Milton Keynes MK76AA,UK [5]School of Geographical Sciences,University of Bristol,Bristol BS81SS,UK

出　　处：《Science Bulletin》2022年第21期2245-2258,共14页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China Basic Science Center for Tibetan Plateau Earth System(41988101);the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0708);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20070301);the National Natural Science Foundation of China-Natural Environment Research Council of the United Kingdom Joint Research Program(41661134049 and NE/P013805/1);the National Natural Science Foundation of China(41941016)。

摘　　要：The uplift of eastern Tibet,Asian monsoon development and the evolution of globally significant Asian biodiversity are all linked,but in obscure ways.Sedimentology,geochronology,clumped isotope thermometry,and fossil leaf-derived numerical climate data from the Relu Basin,eastern Tibet,show at~50–45 Ma the basin was a hot(mean annual air temperature,MAAT,~27℃)dry desert at a low-elevation of 0.6±0.6 km.Rapid basin rise to 2.0±0.9 km at 45–42 Ma and to 2.9±0.9 km at 42–40 Ma,with MAATs of~20 and~16℃,respectively,accompanied seasonally varying increased annual precipitation to>1500 mm.From~39 to 34 Ma,the basin attained 3.5±1.0 km,near its present-day elevation(~3.7 km),and MAAT cooled to~6℃.Numerically-modelled Asian monsoon strength increased significantly when this Eocene uplift of eastern Tibet was incorporated.The simulation/proxy congruence points to a distinctive Eocene Asian monsoon,quite unlike that seen today,in that it featured bimodal precipitation and a winter-wet regime,and this enhanced biodiversity modernisation across eastern Asia.The Paleogene biodiversity of Asia evolved under a continually modifying monsoon influence,with the modern Asian monsoon system being unique to the present and a product of a long gradual development in the context of an ever-changing Earth system.青藏高原东部的隆升、亚洲季风系统的发展和全球重要生物多样性热点的形成紧密相关,对此我们目前知之甚少.结合区域资料,利用藏东稻城热鲁盆地的沉积地层、火山岩U-Pb年龄、古土壤钙质结核团簇同位素古温度和植物化石湿焓定量重建了藏东50~34Ma期间从低海拔(0.6km)沙漠到接近现代海拔(3.5km)高山森林的详细隆升历史.综合植物化石CLAMP、动物化石牙釉质氧同位素和古气候模拟结果,揭示藏东的隆升推动了热带辐合带季风向北渗透,形成了最初的与现今季风系统截然不同的始新世亚洲季风,它具有双峰降水特征和特别潮湿的冬季.此外,热鲁盆地丰富的动植物化石组成表明横断山特殊的生物多样性在45~40 Ma已经建立,比普遍接受的现代亚洲生物多样性是中新世才出现的结论大大提前.藏东始新世以来的崛起与特色亚洲季风系统协同演化产生了复杂的高度波动的生态位,奠定了现代亚洲生物多样性基础.

关 键 词：PALEOELEVATION Asian monsoon BIODIVERSITY FOSSIL Eastern Tibet Relu Basin 

分 类 号：Q16[生物学—普通生物学] P534.613[天文地球—古生物学与地层学] P532[天文地球—地质学]