| Project/Area Number |
12575003
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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 | 海外学術 |
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| Research Field |
生態
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| Research Institution | Tohoku University |
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Principal Investigator |
HIROSE Tadaki Graduate School of Life Sciences, Professor, 大学院・生命科学研究科, 教授 (90092311)
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| Co-Investigator(Kenkyū-buntansha) |
HIKOSAKA Kouki Graduate School of Life Sciences, Associate Professor, 大学院・生命科学研究科, 助教授 (10272006)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥10,300,000 (Direct Cost: ¥10,300,000)
Fiscal Year 2002: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2001: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2000: ¥4,100,000 (Direct Cost: ¥4,100,000)
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| Keywords | Mongolia / Grassland / Vegetation / Climate / Nomadism |
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| Research Abstract |
Mongolian grasslands have been under strong influence of the traditional nomadic activities. We studied how the structure and function of grassland vegetation are influenced by the climate and nomadic activities. In June 1999 we established exclosures with a dimension of100 x 100 m to exclude grazing effects of livestock in mesic (Partizan), typical(Tumentsogt) and dry(Bayan-Unjuul) steppe zone. Inside and outside of the exclosure, ten permanent quadrats were set at each study site. We described species structure of vegetation in the permanent quadrats and harvested plant samples from four 0.5 x 0.5 m quadrates inside and outside of the exclosure in summer (July - August) of 1 999 through 2002. The number of species appeared in an area of 1 m^2 in 1999 was 45 at Partizan, 46 at Tumentsogt and 18 at Bayan-Unjuul. There was no significant difference in the species composition and aboveground plant biomass between inside and outside of the exclosure in 1999. Species-Area curves indicated that species number nearly saturated at 2 m^2 both at Tumentsogt and Bayan-Unjuul, while it was still increasing at Partizan reflecting its higher species diversity. Although the species composition in 2002 was not different from that in 1999, aboveground biomass and the leaf area index were higher in the exclosure than the outside grazing zone. Reduction in soil evaporation due to litter accumulation as well as exclusion of livestock grazing were probably responsible for the higher aboveground growth in the exclosure. Species composition changed with climate. Proportion of gramineae in the aboveground biomass increased and overall species diversity decreased with Bowing of precipitation. There were year-to-year variations in biomass and species composition probably owing to different summer precipitation.
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