2004 Fiscal Year Final Research Report Summary
Verification of top-down effects in the tropical forest ecosystems of South-eastern Asia
Project/Area Number |
13575006
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 海外学術 |
Research Field |
生態
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Research Institution | Research Institute for Humanity and Nature (2003-2004) Kyoto University (2001-2002) |
Principal Investigator |
YUMOTO Takakazu Research Institute for Humanity and Nature, Professor, 研究部, 教授 (70192804)
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Co-Investigator(Kenkyū-buntansha) |
MARUHASHI Tamaki Musashi University, Faculty of Humanities, Professor, 人文学部, 教授 (20190564)
NOMA Naohiko University of Shiga Prefecture, Lecturer, 環境科学部, 講師 (80305557)
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Project Period (FY) |
2001 – 2004
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Keywords | frugivory / fruit characteristics / hornbill / population fluctuation / seed dispersal / seed predation / small mammals / tropical forest |
Research Abstract |
1) Fruit consumption on the canopy by 4 species of hornbills, white-handed gibbons, pig-tail monkeys and other frugivores was observed to reveal the relationships between fruit consumers and fruit characteristics in Khao Yai National Park, Thailand, a moist tropical forest Among 259 plant species, plants having a large and lipid-rich fruit with 1-seed were observed to be consumed and be dispersed only by hornbills. So these plants can be called "hornbill dispersed plants". White-handed gibbons preferred sugar-rich fruits, and pig-tailed monkeys often ate unripen fruits and acted mainly as seed predators. 2) Seeds and seedlings dispersed around nest trees of hornbills were marked and monitored during 3 years. Most of seedlings near nest trees disappeared during 3 year, however, some seedlings of "hornbill dispersed plants" had survived. Seedling s were suffered by heavy seed predation, which caused by small mammals attracted by a high density of seeds and seedlings around nest trees. 3) Fruit consumption on the ground was studied by camera trapping, and population fluctuation of small mammals, Maxomys surifer and Niniventer bukit was monitored during 3 years by capture-recapture method. The biomass of two main seed predators, M. surifer and N. bukit (2150 g/ha) was twice and three times as high as rodents recorded in other tropical forests (e.g. 616 g/ha in Huai Kha Khaeng). These two species of rodents showed highest population density in the middle of dry period. But the breeding season of two rodents differed, which suggested some relationships of food fruit/seed of them. 4) In conclusion, the seeds and seedlings in the forests where hornbills are extinct will be suffered by heavier seed predation caused by heavier accumulation of seeds around mother trees, so that the regeneration of trees will become difficult at least for some tree species.
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Research Products
(11 results)
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[Journal Article] Dispersal of Aglaia apectabilis: A large-seeded tree species in a moist evergreen forest in Thailand.2004
Author(s)
Kitamura, S., Suzuki, S., Yumoto, T., Poonswad, P., P.Chuailua, Plongmai, K., Noma, N., Maruhashi, T., Suckasam, C.
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Journal Title
Journal of Tropical Ecology 20
Pages: 421-427
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Pattern and impact of hornbill seed dispersal at nest trees in a moist evergreen forest in Thailand.2004
Author(s)
Kitamura, S., Yumoto, T., Poonswad, P., Noma, N., Chuailua, Plongmai, K., Maruhashi, T., Suckasam, C.
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Journal Title
Journal of Tropical Ecology P. 20
Pages: 545-553
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Interactions between fleshy fruits and frugivores in a tropical seasonal forest in Thailand.2002
Author(s)
Kitamura, S., Yumoto, T., Poonswad, P., Chuailua, P., Plongmai, K., Maruhashi, Y., Noma, N.
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Journal Title
Oecologia 133
Pages: 559-572
Description
「研究成果報告書概要(欧文)」より
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