Study about influence to root uptake by supplying of radiocesium to deeper mineral soil by stemflow

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15563
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Imamura Naohiro 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 (30732383)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 放射性セシウム / 樹幹流 / 深部浸透 / 経根吸収 / 安定同位体セシウム / 細根

Outline of Final Research Achievements

Stemflow contained more dissolved radioactive cesium than suspended radioactive cesium. In Konara oak trees with a lot of stemflow, the amount of dissolved and exchangeable radioactive cesium in the soil was high at the location where stemflow flowed into the soil. Whereas the vertical distribution of dissolved radioactive cesium in the soil was constant, exchangeable radioactive cesium was high in the soil surface layer. This suggested that radioactive cesium had been supplied to the soil surface layers by factors other than stemflow. Furthermore, since oak trees were estimated to absorb radioactive cesium from the soil surface, the absorption of radioactive cesium by trees was not only influenced by the supply of radioactive cesium to the soil by stemflow.

Free Research Field

森林科学

Academic Significance and Societal Importance of the Research Achievements

本研究は、樹木近傍の放射性セシウムの供給源である樹幹流に着目し、樹木に吸収される溶存態と交換態の放射性セシウムの分布と吸収の解明を目的に取り組まれた課題である。本成果は、土壌から樹木への放射性セシウム吸収メカニズムの解明に繋がるため、土壌から樹木への放射性セシウムの吸収を低下させる技術の開発に繋がる可能性がある。このことは、事故から10年以上経過した現在でも、しいたけ原木の出荷制限や林業の停滞が続いている福島の森林・林業の復興に貢献できると考えられる。