title: Temporal changes in radiocesium deposition in various forest stands following the Fukushima Dai-ichi Nuclear Power Plant accident.
abstract: In this study, we investigated the transfer of canopy-intercepted radiocesium to the forest floor following the Fukushima Dai-ichi Nuclear Power Plant accident. The137Cs content of throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantations of Japanese cedar) and a deciduous mixed broad-leaved forest stand (oak with red pine) from July 2011 to December 2012. The forest floor of cedar stands had received higher levels of additional137Cs deposition compared with the mixed broad-leaved stand during the sampling period. The cumulative137Cs deposition during the study period was 119 kBq m-2for the mature cedar stand, 105 kBq m-2for the young cedar stand, and 41.5 kBq m-2for the broad-leaved stand. The deposition of137Cs to the forest floor occurred mainly in throughfall during the first rainy season, from July to September 2011 (<200 d after the initial fallout); thereafter, the transfer of137Cs from the canopy to forest floor occurred mainly through litterfall. A double exponential field-loss model, which was used to simulate the removal of137Cs from canopies, was the best fit for the temporal changes in the canopy137Cs inventory.
authors.affiliation: Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan. Electronic address: hiros980@ies.life.tsukuba.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Onda
authors.affiliation: Asia Air Survey Co., LTD, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Hisadome
authors.affiliation: Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Loffredo
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kawamori
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D032485:Cryptomeria; D065928:Forests; D062406:Fukushima Nuclear Accident; D007564:Japan; D028223:Pinus; D018515:Plant Leaves; D018547:Plant Stems; D029963:Quercus; D011834:Radiation Monitoring; D011847:Radioactive Fallout; D011891:Rain / Q000737:chemistry; D027925:Viburnum
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout
keywords: Canopy interception; Cesium-137; Forest environment; Fukushima Dai-ichi Nuclear Power Plant accident; Transfer