Improvement of model prediction of radiocesium cycling in forested ecosystem by adaptation of stable cesium dynamics

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04522
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Forest science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Kobayashi Masahiro 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 (50353686)
• Co-Investigator(Kenkyū-buntansha): 池田 重人 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 (60353570) ; 伊藤 優子 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 (60353588) ; 橋本 昌司 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 (90414490)
• Co-Investigator(Renkei-kenkyūsha): Noguchi Kotaro 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 (70353802)
• Research Collaborator: Hiruta Toshihide 福島県相双農林事務所, 森林林業部, 主任主査
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 森林 / 放射性セシウム / 安定セシウム / モデル / 予測

Outline of Final Research Achievements

We monitored the inventory and transport of radioactive and stable cesium isotopes in forests in Fukushima and Ibaraki prefectures. Rradiocesium concentrations in litterfall, throughfall, litter leachate, and soil water gradually decreased throughout the monitoring period. Following infiltration, the radiocesium concentration in soil water rapidly decreased with depth, demonstrating the strong ability of clay minerals to capture radiocesium. In contrast, the stable cesium concentration in soil water was almost constant with depth. These findings suggest that the supply of stable cesium from soil material due to weathering is balanced by its capture by clay minerals and leaching by flowing water. Observed data was adapted to improve the prediction of radiocesium dynamics using in forest ecosystem. The stable cesium data improve the model parameterization through expressing the difference of the root uptake of radiocesium by sites.

Free Research Field

森林土壌学