Studies on vegetation recovery in an island ecosystem in the Bonin Islands
| Project/Area Number |
15370013
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
KACHI Naoki Tokyo Metropolitan University, Department of Biological Sciences, Professor, 都市教養学部理工学系, 教授 (30124340)
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| Co-Investigator(Kenkyū-buntansha) |
KATOH Hidetoshi Tokyo Metropolitan University, Department of Biological Sciences, 都市教養学部理工学系, 助手 (50305413)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2004: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2003: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Bonin Islands / oceanic islands / vegetation recovery / Leucaena leucocephala / genetic polymorphism / vegetation succession / Boninia / AFLP analysis / 大洋島 / 遺伝子系図 / DNA多型 |
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| Research Abstract |
We investigated direct and indirect effects of an invasion of alien shrub, Leucaena leucocephala, on subsequent establishment of native mid-successional tree, Schima mertensiana at early-successional stages in Chichijima Island, a subtropical oceanic island in Japan. We compared effects of dominant species and S.jamaicensis on seed germination and growth of transplanted seedlings of S.mertensiana between the two sites. Growth of S.jamaicensis established at the L.leucocephala dominated site was lower than those at T.orientalis dominated site. Seed germination rate and seedling growth rate of S.mertensiana at the L.leucocephala dominated site were lower than those at the T.orientalis dominated site. These results suggest that there was a prevention of establishment of S.mertensiana caused by an inhibition of seed germination and seedling growth of S.mertensiana by L.leucocephala directly at L.leucocephala invaded communities, which potentially changed a successional pathway in the communities.
The amount and distribution of genetic variations were examined in 16 populations of endemic genus Boninia and an endemic species Euodia nishimurae in Bonin Islands. Based on allozyme analysis, two genetic isolated groups were recognized in B. grisea var.grisea, while distributional patterns or numbers of trees were not affected to levels of genetic diversities. For all taxa, high genetic diversities for oceanic endemics were detected, and most of diversities were possessed within populations. High genetic diversity and low population differentiation is a unique character combination contrary to general concepts of oceanic endemics.
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Report
(4 results)
Research Products
(9 results)
