[en] The accumulation rate for different mushroom species varies, but there does not seem to be any clear correlation between the ¹³⁷ Cs concentrations (Bq/kg fw) in the 1990-1991 mushrooms and the length of the ecological half-life. This is despite the fact that the highest concentrations have been measured in Cortinarius armillatus, the ecological half-life of which appears to be of the order of the physical T of ¹³⁷ Cs, 30 y. All the Russula species have had low concentrations, although the half-lives are rather long 11-18 y. Lactarius trivialis has highers levels than the other analysed Lactarius species but there is no correlation with the half-lives. The type of forest stand does not seem to have any ef-fect on the caesium concentrations, except possibly for Rozites. (AU)