Format: ORAL

Jun Wen1, Alicia Talavera1, Zhiyao Ma2, Limin Lu3, Richard Hodel1, Liang Zhao4, Gabriel Johnson1, Virginia Valcrcel5, Russell Barrett6, Elizabeth Zimmer1, Zelong Nie7

1 Department of Botany, Smithsonian Institution, Washington, USA 2 Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China 3 Institute of Botany, Chinese Academy of Sciences, Beijing, China 4 College of Life Sciences, Northwest A&F University, Yangling, China. 5 Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain 6 National Herbarium of New South Wales, Mount Annan, Australia 7 College of Biology and Environmental Sciences, Jishou University, Jishou, Hunan 416000, China.

The Asian Australasian regions harbor rich biodiversity and represent an ideal natural laboratory to explore biogeographic exchanges and pathways, tropical temperate biome transitions, and plant diversification in response to tectonic movements and climate changes. In this study, we analyze the biogeographic exchanges between Asia and Australasia in a global context in Araliaceae, Calycanthaceae, the Gymnostachydoideae-Orontioideae clade of Araceae, the Leeaceae/Vitaceae clade, Prunus of Rosaceae, Toxicodendron and its close relatives of Anacardiaceae, and the conifer family Taxaceae. Our analyses reveal extensive biogeographic exchange among major Gondwanan landmasses in the Cretaceous and early Paleogene. Antarctica, Africa, India, and South America played an important role in the biotic exchange of disjunct plants between Asia and Australasia in the early phase, with the existence of the Antarctic land bridge linking Australia, Antarctica and South America, and the Kerguelen Plateau land bridge connecting Antarctica and India. Hence the Asian and Australasian biotic exchanges in the Cretaceous and early Paleogene were mostly via indirect migration and dispersal. Subtropical East Asia and the adjacent tropical southeast Asia developed a rich forest flora that was highly influenced by the East Asian monsoon, the Indian monsoon, and the uplift of the Qinghai-Tibetan plateau. During the Neogene, biogeographic exchange between the Sunda and Sahul regions became highly active after the collision of the Australian continental crust with southeast Asia, with a more dominant Sunda-to-Sahul dispersal pattern. Continental Asia, including tropical Southeast Asia to subtropical East Asia, was a dominant source area for the later Miocene/Pliocene phase of the Asian Australasian biotic exchanges. Our results also support dispersals from continental Asia to New Guinea, independent dispersals from continental Asia to Sunda and Sahul in a given lineage, and a recent biogeographic corridor linking Taiwan, the Philippines and New Guinea in the late Neogene via long distance dispersal.