J Syst Evol ›› 2019, Vol. 57 ›› Issue (2): 114-128.DOI: 10.1111/jse.12445

• Research Articles • Previous Articles     Next Articles

Oligocene–Neogene fossil history of Asian endemic conifer genera in Japan and Korea

Atsushi Yabe1*, Eunkyoung Jeong2, Kyungsik Kim3, and Kazuhiko Uemura1   

  1. 1Department of Geology and Paleontology, National Museum of Nature and Science, Tsukuba 305-0005, Japan
    2Museum of Natural History, Sungshin University, Seoul 01133, Republic of Korea
    3Department of Biological Sciences, Chonbuk National University, Jeonju 54896, Republic of Korea
  • Received:2018-01-30 Accepted:2018-06-10 Online:2018-06-15 Published:2019-03-01

Abstract: Temporal and spatial changes of ten conifer genera that are endemic to East Asia were analyzed based on fossil data from humid temperate forests in the Japanese Islands and Korean Peninsula to elucidate the phytogeographic history, and to understand differences between those genera eliminated from the Japanese Islands and those that remained extant. All these genera, except for Thujopsis, have existed in the area since the Paleogene and remained in the Japanese islands after initial separation from the continent at the early–middle Miocene. Fossil representatives of locally extinct six genera have tendencies to adapt to wider ranges of climatic conditions than their modern relatives. Metasequoia, Glyptostrobus, and Taiwania began to change their distributions since the late Miocene possibly through habitat partitioning. Keteleeria, Pseudolarix, and Cunninghamia appeared to have expanded their habitat toward warmer conditions during the mid‐Miocene Climatic Optimum and then became restricted to warmer forest vegetation by the end of Pliocene. Overall changes in their distribution can be explained by climatic effects. On the contrary, three genera endemic to Japan (Sciadopitys, Cryptomeria, and Thujopsis) followed clearly different trends from the others. Cryptomeria and Thujopsis were especially adapted to cooler‐temperate climate and they retained their habitat areas in the northern part of Japan. During the late Miocene–Pliocene, the islands connected with the Eurasian continent again, which probably acted as a corridor for warm‐adapted genera to disperse southwest. Current data suggest that ecological requirements of each genus might be essential to determine whether they could survive on the Japanese Islands.

Key words: Asian endemic conifers, circum-Japan Sea area, fossil records, Oligocene–Neogene, paleoecology