2022 Fiscal Year Final Research Report
Research on revegetation of volcanic devastated areas using erosion landforms to promote establishment of pioneer grasses
| Project/Area Number |
19K06134
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 40010:Forest science-related
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| Research Institution | Forest Research and Management Organization |
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Principal Investigator |
Ogawa Yasuhiro 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (50353628)
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| Co-Investigator(Kenkyū-buntansha) |
上條 隆志 筑波大学, 生命環境系, 教授 (10301079)
廣田 充 筑波大学, 生命環境系, 教授 (90391151)
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Keywords | 三日月形緑化資材 / 植生回復 / 侵食 / リル |
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| Outline of Final Research Achievements |
In an erosion topography (rill) on the degraded slope of Oyama, Miyakejima, one weir consisting of test materials, a wooden fence, and stone gravel was installed at each of the three rill ends. Observations of sediment discharge from the weirs showed that although the test materials stored the same amount of sediment in the weirs as the other materials, 30 to 40% of the sediment passed through the test materials compared to the other materials. Streamflow experiments were conducted in rills to determine the effect on plant establishment. Roughness coefficients in rills had higher values than in inter-rill areas, and values in rills with vegetation were higher than in rills during periods of ash fall deposition. Vegetation cover was significantly different at the 5% significance level in the test material area compared to the control area during the summer after 2 years of installation. The results demonstrate that the test materials can be used as a natural recovery for pioneer plants.
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| Free Research Field |
緑化工学
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| Academic Significance and Societal Importance of the Research Achievements |
リルは侵食地形の一つであり土砂流出の発生源であると一般に考えられていたが、リルの粗度が高まることによって、パイオニア草本種子が地表流で流されずに、リルに自然定着が促されていることが本研究で示唆された。侵食地形であるリルに三日月形緑化資材を設置することによって土砂流出がコントロール可能となり、リルに定着するパイオニア草本が自然回復することを実証した。本研究によって微地形によらず草本種子で全面緑化する既存工法とは異なり、微地形に配慮した自然回復緑化手法が検証された。
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