title: Spatial variation in the (137)Cs inventory in soils in a mixed deciduous forest in Fukushima, Japan.
abstract: The spatial variation of the radiocesium inventory in forest soil was studied c.a. 44 km northwest of the Fukushima Daiichi Nuclear Power Plant, Japan. This study focuses on the effects of canopy interception and downward transfer from the forest canopy to the forest floor via stemflow and throughfall. We established a study plot (400 m(2)) in the canopy layer of a secondary mixed deciduous forest dominated by Japanese oak (Quercus crispula) and Japanese fir (Abies firma), in August and November 2014. Soil was sampled from 0 to 5 cm depth and (137)Cs was measured under the canopy using a 2-m grid and also at the tree trunk bases. We divided the study plot into the five different types of subplot according to the canopy projection areas and the tree species for the analysis. The geometric mean and coefficient of variation of the (137)Cs inventory were 202 kBq m(-2) and 0.11 (0.52 in the arithmetic coefficient of variation), respectively. Within the forest, the variation in the (137)Cs inventory under trees was larger than in crown gap areas. The large spatial variation may be attributed to canopy interception of the initial deposition and downward transfer of radiocesium via stemflow and throughfall.
authors.affiliation: Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8521, Japan. Electronic address: taka-momo@hiroshima-u.ac.jp.
authors.forename: Momo
authors.initials: M
authors.lastname: Takada
authors.affiliation: Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8521, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8521, Japan; Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Takahara
authors.affiliation: Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, 739-8521, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Okuda
mesh_terms: D028202:Abies; D002588:Cesium Radioisotopes / Q000032:analysis*; D065928:Forests; D062406:Fukushima Nuclear Accident; D007564:Japan; D029963:Quercus; D011834:Radiation Monitoring; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D012990:Soil Pollutants, Radioactive
keywords: Canopy interception; Radiocesium; Spatial heterogeneity; Stemflow; Throughfall