| Project/Area Number |
11440223
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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 |
生態
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TODA Masanori j. Hokkaido Univ., The Institute of Low Temperature Science, Professor, 低温科学研究所, 教授 (40113592)
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| Co-Investigator(Kenkyū-buntansha) |
KUDO Gaku Hokkaido Univ., Graduate School of Environmental Earth Science, Assistant professor, 大学院・地球環境科学研究科, 助教授 (30221930)
HIURA Tsutom Hokkaido Univ., Field Science Center for Northern Biosphere, Assistant professor, 北方生物圏フィールド科学センター, 助教授 (70250496)
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| Project Period (FY) |
1999 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥14,400,000 (Direct Cost: ¥14,400,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2001: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2000: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1999: ¥7,200,000 (Direct Cost: ¥7,200,000)
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| Keywords | Bumblebee / Flower mass of trees / Understory plant / Spatio-temporal distribution / Annual fluctuation / Indirect effect / Population dynamics / Reproductive success / 林冠開花性植物 / 林床性草本植物 / エゾエンゴサク / 開花フェノロジー / フェノロジー / 虫媒植物 / 花資源 / 結実率 / 春植物 / 貯蔵養分 / アトラクション効果 / 垂直分布 |
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| Research Abstract |
In order to examine the hypothesis that annual fluctuation of floral resources of canopy trees generates that of pollinator population, then that of reproductive success of understory plant, that shars the pollinator, flowering in later seasons, we investigated following three components :
(1) Floral resource amount of entomophilous trees : we quantitatively assessed about twenty entomophilous trees including eight species frequently visited by bumblebees. Reproduction system of Fraxinus lanuginosa with high fluctuation in the number of flower was revealed. As for another masting tree Styrax obbasia, it was revealed that trasport of photosynthetic substrates from the non-reproductive shoot to reproductive shoot played an important role for determination of the number of flower by the tracing such substrates.
(2) Abundance of bumblebees : In forest site the number of queens (estimated by mark-recapture method) and the number of workers correlated with the number of inflorescences of trees
… More
in the year and that in the previous year, respectively. Seasonal change in vertical distribution of bumblebees and trees implied that bumblebee change the flight height associated with the floral resource amount of canopy trees. From the seasonal patterns of workers in forest and open sites indicated that Bombus ardens showed similar seasonal patterns in both habitats while B. hypocrita tended to change main habitats between forest and open site. This suggest that B. hypocita could utilize more effectively the floral resource in open habitats for the population growth than B. ardens.
(3) Reproductive success of an understory plant : Assessment of reproduction system and seed production of ten species of understory plants for four years documented the general patterns in the reproduction system of understory plants including Corydalis ambigua, a spring ephemeral herb pollinated by bumblebees. Then, relative influence of resource limitation and pollen limitation on seed set of understory plants by comparing seed set between places in different light condition, understory and forest margin.
These studies quantitatively assessed annual fluctuation of pollination system in temperate forest for the first time, and our hypothesis was supported in general. These suggest that long-term monitoring of reproduction of flower and pollinator abundance is essential to assess the dynamic aspects of pollination system. Less
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