| Project/Area Number |
18K05728
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 40010:Forest science-related
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| Research Institution | Shimane University |
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Principal Investigator |
Kawaguchi Hideyuki 島根大学, 学術研究院環境システム科学系, 准教授 (40202030)
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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| Keywords | 国内外来種 / 分布拡大 / 遺伝構造 / 更新 / 先駆樹種 / 雌雄異株 / 在来種 / 植生管理 |
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| Outline of Final Research Achievements |
A dioecious pioneer tree Litsea cubeba was distributed in a part of Honshu, western Kyushu, and Nansei Islands in Japan, but recently its distribution has been reported to be expanding. DNA analysis of 16 individuals from each of 43 sites showed that L. cubeba of the pre-expansion sites were divided into two groups: the Nansei Islands with high genetic diversity and others. The expanded L. cubeba belonged to one of the two groups. In Tottori Precf., populations introduced from the two groups were adjacent to each other and were becoming intermixed. The genetic diversity of populations in the expanded sites were not lower than those in the pre-expansion sites, suggesting that large numbers of individuals were introduced and that dioecy affected genetic diversity. At the clearcut site, L. cubeba was highly competitive to native pioneer species due to the formation of a buried seed population, a wider range of seedling occurrence, and greater initial growth of seedlings and sprouts.
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| Academic Significance and Societal Importance of the Research Achievements |
分布拡大する前のアオモジが２つの遺伝的に異なる集団からなり、それぞれの集団から移入され、分布拡大している状況、さらに両者の混交も示すことができた。また、アオモジが雌雄異株であることの遺伝構造および個体群動態への影響を考察することができた。
アオモジは伐採など攪乱された土地で在来種に置き換わり、下刈りなど植生管理や樹木の多様性に影響すると予想された。皆伐造林において、埋土種子から発生する大量の実生と、切株から発生する萌芽の旺盛な成長に対して、下刈りの追加と除伐の徹底が必要となる。鑑賞、切花、精油抽出などに利用する植栽は、雄株または雌株のみとして、逸出を防ぐ必要がある。
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