Biogeographic diversification of Mahonia (Berberidaceae): Implications for the origin and evolution of East Asian subtropical evergreen broadleaved forests.
Xiao-Hong Chen, Kun-Li Xiang, Lian Lian, Huan-Wen Peng, Andrey S Erst, Xiao-Guo Xiang, Zhi-Duan Chen, Wei Wang
Author Information
Xiao-Hong Chen: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Kun-Li Xiang: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Lian Lian: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Huan-Wen Peng: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Andrey S Erst: Central Siberian Botanical Garden of the Siberian Branch of Russian Academy of Sciences, Zolotodolinskaya str. 101, Novosibirsk 630090, Russia; Laboratory of Systematics and Phylogeny of Plants, Tomsk State University, Tomsk 634050, Russia.
Xiao-Guo Xiang: Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang 330031, China.
Zhi-Duan Chen: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Wei Wang: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: wangwei1127@ibcas.ac.cn.
The subtropical evergreen broadleaved forests (EBLFs) inhabit large areas of East Asia and harbor rich biodiversity and high endemism. However, the origin and evolution of biodiversity of East Asian subtropical EBLFs remain poorly understood. Here, we used Mahonia (Berberidaceae), an eastern Asian-western North American disjunct evergreen genus, to obtain new insights into the historical assembly of this biome. We present the most comprehensive phylogenetic analysis of Mahonia do date based on six nuclear and plastid loci. Using the phylogenetic framework, we estimated divergence times, reconstructed ancestral ranges, inferred evolutionary shift of habitats, and estimated diversification rates. Mahonia and each of its two groups (Orientales and Occidentales) are strongly supported as monophyletic. Mahonia originated in western North America during the late Eocene (c. 40.41 Ma) and subsequently dispersed into East Asia prior to the early Oligocene (c. 32.65 Ma). The North Atlantic Land Bridge might have played an important role in population exchanges of Mahonia between East Asia and western North America. The western North American Occidentales began to diversify in summer-dry climates and open landscapes in the early Miocene, whereas the eastern Asian Orientales began to diversify in subtropical EBLFs in the early Miocene and furthermore had a rapid lineage accumulation since the late Miocene. The net diversification rate of Mahonia in eastern Asia appeared to be higher than that in western North America, which is ascribed to lower extinction rates and ecological opportunity. Our findings suggest that western North America is a source of biodiversity of East Asian subtropical EBLFs. This biome in eastern Asia began to rise in the early Miocene and further diversified in the late Miocene, driven by the intensifying East Asian summer monsoon during these two periods.
