[en] The present report about an EC-Workshop 'The transfer of Radionuclides in Natural and Semi-Natural Environments', which took place in Udine (Passariano), 11^th to 15^th september 1989, deals with the manifold new results of radioecology, which were obtained after the reactor accident in Chernobyl. Especially those mechanisms, which lead to the increased radionuclide concentration in foodstuff from natural and seminatural ecosystems are elucidated and some possibilities to decrease the radionuclide transfer to man are discussed. (Authors)