Reduced colonization by soil invertebrates to irradiated decomposing wood in Chernobyl A.P. Møller a, ⁎, T.A. Mousseau b a Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, F-91405 Orsay Cedex, France b Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA HIGHLIGHTS • Wood quality and ambient radiation were used to test for deficient defenses against decomposers. • Abundance of soil invertebrates ex- tracted with mustard powder decreased with ambient radiation. • There were more soil invertebrates under uncontaminated than contami- nated wood. • There was a temporal increase in abun- dance of soil invertebrates under wood slices. GRAPHICAL ABSTRACT abstract article info Article history: Received 27 March 2018 Received in revised form 13 July 2018 Accepted 15 July 2018 Available online xxxx Editor: Henner Hollert Soil is inhabited by a range of microbes, invertebrates and vertebrates that disintegrate and decompose dead wood and leaf litter. These communities can be perturbed by ionizing radiation from natural radiation sources or from radiation originating from nuclear accidents such as those at Chernobyl, Fukushima and Three Mile Is- land. We used experimental manipulations of wood quality due to differences in exposure to ionizing radiation among tree trunks and ambient radiation levels of the soil to test the hypothesis that radioactively contaminated wood would result in a negative correlation between the abundance of soil invertebrates colonizing slices of wood and level of radioactive contamination. We extracted soil invertebrates underneath decomposing wood using mustard powder diluted in water. The abundance of soil invertebrates extracted was highly repeatable at study sites and decreased with increasing ambient radiation and total dose measured with thermoluminescent dosimeters (TLDs). Four 10 cm thick slices of ca. 70-year old Scots pines (Pinus sylvestris) were deposited at 20 sites and the invertebrate taxa and their colonization and their abundance was assessed annually during 2014–2017. There were more soil invertebrates under uncontaminated than contaminated slices of wood. In ad- dition, there were more soil invertebrates in areas with less ambient radioactivity, and there was an interaction effect between contamination of wood and ambient radiation implying that the role of contamination differed among slices. Finally, there was an increase in the abundance of soil invertebrates under wood slices during 2013–2017 implying that the abundance of soil invertebrates increased over time. These findings imply that the abundance of soil animals colonizing wood slices was dependent on background radiation, radioactive con- tamination of wood and the interaction between contamination of wood and ambient radiation. © 2018 Elsevier B.V. All rights reserved. Keywords: Accumulative effects of radiation Chernobyl Dead wood Decomposition Ionizing radiation TLD Science of the Total Environment 645 (2018) 773–779 ⁎ Corresponding author. E-mail address: anders.moller@u-psud.fr (A.P. Møller). https://doi.org/10.1016/j.scitotenv.2018.07.195 0048-9697/© 2018 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv