title: Different cesium-137 transfers to forest and stream ecosystems.
abstract: Understanding the mechanisms of (137)Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of (137)Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of (137)Cs in stream litter was significantly lower than in forest litter, the result of (137)Cs leaching from litter in stream water. The difference in (137)Cs concentrations between the two types of litter was reflected in the (137)Cs concentrations in the animal community. While the importance of (137)Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of (137)Cs through terrestrial and aquatic ecosystems, and that (137)Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem.
authors.affiliation: Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: boundary.0008@gmail.com.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sakai
authors.affiliation: Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: gomit@cc.tuat.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Gomi
authors.affiliation: Faculty of Environmental Earth Science, Hokkaido University, N10, W5, Kita-ku, Sapporo, Hokkaido 060-0860, Japan. Electronic address: negishi@ees.hokudai.ac.jp.
authors.forename: Junjiro N
authors.initials: JN
authors.lastname: Negishi
authors.affiliation: Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: kawasemimejiro@hotmail.com.
authors.forename: Aimu
authors.initials: A
authors.lastname: Iwamoto
authors.affiliation: Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: salvelinus.imbrius@gmail.com.
authors.forename: Kengo
authors.initials: K
authors.lastname: Okada
mesh_terms: D000818:Animals; D002588:Cesium Radioisotopes / Q000032:analysis*; D017753:Ecosystem; D020387:Food Chain; D065928:Forests; D045483:Rivers / Q000737:chemistry*; D014197:Trees / Q000737:chemistry*
chemical_list: D002588:Cesium Radioisotopes
keywords: Detrital food chain; Frogs; Macroinvertebrates; Radiocesium; Resource subsidy; Salmonid fishes