2021 Fiscal Year Final Research Report
Transfer of radiocesium from canopy to forest floor in deciduous oak dominated forests and the prediction of resume of leaf litter origin compost production
| Project/Area Number |
19K06140
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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 | Utsunomiya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
飯塚 和也 宇都宮大学, 農学部, 教授 (20344898)
逢沢 峰昭 宇都宮大学, 農学部, 准教授 (70436294)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | 放射性Cs移行過程 / ブナ林 / コナラ林 / 腐葉土生産 / 暫定許容値 / 落葉利用再開予測 |
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| Outline of Final Research Achievements |
In Japanese beech forests and Konara oak forests in northern Tochigi Prefecture with different initial deposition of radioactive cesium (Cs), we clarified the transfer process of radioactive Cs to tree trunks, including large diameter trees, and overstory branches and leaves, and compared it with radioactive Cs in litter on the forest floor to understand the transfer process from tree trunks and overstory leaves to fallen leaves. In addition, annual observations of radioactive Cs in litter, sedimentary organic matter layer on the forest floor (A0), and surface soil (A) were conducted to predict the availability of leaf compost use. As a result, it was found that delayed penetration of radioactive Cs at the lower zone of large diameter trees of the species, increased concentration of radioactive Cs in overstory branches and leaves due to concentration effect, and consequently increased concentration of radioactive Cs in fallen leaves, which in turn determines the availability for use.
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| Free Research Field |
森林生態学・育林学
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| Academic Significance and Societal Importance of the Research Achievements |
福島原発事故による放射性セシウム（Cs）の降下沈着影響下の奥山ブナ類林と里山ナラ類林の両ブナ科落葉広葉樹優占林では、事故後4-5年の初期段階から準平衡段階または安定段階とよばれる、分布変化が小さい状態に移行していると考えられる。一部大径木では完全に樹体に侵入していないものの放射性Csは森林生態系でほぼ循環過程に入っており、落葉における放射性Csの暫定基準値超えは継続するものと考えられる。森林における落葉堆肥の利用可能の可否は、放射性Csの初期沈着量による予測されるが、放射性Csは循環過程にあるため初期段階の予測より遅延する可能性があり、今後とも放射性Csモニタリングの継続が必要である。
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