| Project/Area Number |
01041014
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Field Research |
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| Research Institution | Chiba University |
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Principal Investigator |
OHSAWA Masahiko Laboratory of Ecology, Faculty of Science, Chiba University, 理学部, 助教授 (80092477)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Masatoshi Natural History Museum and Institute, Chiba, 主任研究員
TSUCHIDA Katsuyoshi Lab. Nature Conservation, Fac. of Liberal Arts, Shinshu Univ., 教養部, 教授 (70089093)
NUMATA Makoto Shukutoku University, 社会福祉学部, 教授 (10009037)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 1990: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1989: ¥8,600,000 (Direct Cost: ¥8,600,000)
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| Keywords | Altitudinal Zonation / Forest Vegetation / Grassland Vegetation / Weeds / Climate / Dry Valley / Landform / Bhutan |
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| Research Abstract |
Life Zone Ecology of The Bhutan Himalaya II.
The second phase study is focused on the subtropical part of the Bhutan Himalaya. Climatic analysis of the dry valley along the Sankosh river clarified the main factor which cause the occurrence of dry valley is the strong southerly (valley) wind which reach maximum velocity at 14 or 15 local time when the temperature reaches maximum. The high temperature, the large gradient of water vapour pressure and the strong wind make the evapo transpiration large. Landform and tectonic movement of Bhutan was studied in middle reaches of several main rivers. Bedding planes of older fluvial deposits at the Wangdiphodrang Dzong indicates the relative uplift of the lower reaches from WangdiyPhodrang against the upper ones and suggests the uplift of the southern High Himalaya belt.
Vegetation structure and its human modification were studied in the subtropical zone ranging from 1000 to 2500 m. In natural forests, there are many tropical elements such as Altingia excelsa, Exbucklandia populnea, Sloanea sterculiaceus, Toonaciliata, Acrocarpus fraxinifolius, etc. , however, the repeated human disturbances such as shifting cultivation and coppicing had modified the forests into less diversified lauro-fagaceous forests. The pattern is further intensified by xeric-mesic gradients along the topo-edaphological gradients, and grazing by domestic animals. Farmland weeds and pastures were studied extensively. A dwarf bamboo grasslands like Pleioblastus pastures on Mt. Aso and Mt. Kuju was found in central Bhutan which is dominated by dwarfbamboo, Yushania. It is an evergreen bamboo grazed by cow and Yaku throughout the year. Grasslands are also modified into waste lands dominated by Artemisia, Senecio, Rumex and Arundinaria.
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