Most of the nuclear facilities built since the Second World War have ceased active operation and have been decommissioned. Some of the sites are heavily contaminated with radioactive substances. Correct and efficient action to mitigate the radiological consequences of such contamination will only be possible when the behaviour of radionuclides in the terrestrial environment is sufficiently well known. Yet radioecologists often find it difficult to study the transfer of radioactivity in agricultural land and semi-natural ecosystems, because of the complexity and diversity of such environments....