Phytogeographical study of the Tertiary warm elements between Japanese Islands and Taiwan

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05599
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: National Museum of Nature and Science, Tokyo
• Principal Investigator: Yabe Atsushi 独立行政法人国立科学博物館, 地学研究部, 研究主幹 (20634124)
• Co-Investigator(Kenkyū-buntansha): 藤木 利之 岡山理科大学, 理学部, 准教授 (10377997)
• Research Collaborator: Jeong Eun-Kyoung
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 古植物地理 / 琉球列島 / 台湾 / 古気候 / 古生態

Outline of Final Research Achievements

Phytogeographical studies of two conifer genera, Cunninghamia and Taiwania, that are endemic to Taiwan have been conducted based on Pliocene-early Pleistocene fossils from the Ryukyu Archipelago and Kyushu Island. By using multiple plant organs, such as leaves, shoots, seeds, pollen grains, and woods, we successfully identified at least the former ones as extant species in Taiwan. Paleoclimate (especially temperature) analysis using either of floral composition and physiognomy suggested that they have inhabited in similar or cooler conditions than that of the extant species. Therefore, we succeeded to tested the hypothesis that such "warm elements" have distributed in Japan well before the Pliocene and have expanded their distribution to Taiwan across the land bridge like Ryukyu Archipelago during the cooling of climate conditions.

Free Research Field

古植物学

Academic Significance and Societal Importance of the Research Achievements

日本列島から見つかる台湾現生属の化石は、しばしば温暖要素と呼ばれ、温暖期に南から分布を広げた要素と捉えられることが多かったが、本研究によって、それらが従来とは全く逆の経路で分布を広げた可能性を指摘することができた。これら台湾現生属は現在、台湾や中国の一部の地域にのみ生育する種であり、生育地の保全が課題となっている。本研究により明らかとなった分布地の成立史や潜在的な生態的分布範囲は、それらの種の保全にも役立てられる可能性がある。