Ash (Fraxinus excelsior L.), birch (Betula spp.), hazel (Corylus avellana L.), sessile oak [Quercus petraea (Mattuschka) Liebl.] and sycamore (Acer pseudoplatanus L.) leaf litters from a non-polluted and a heavily sulphur dioxide (SO2)-polluted woodland were fumigated with environmentally-realistic concentrations (0.010–0.030 μl l−1) of SO2 for 16–68 wk in an open-air field-fumigation experiment. Fumigation markedly increased sulphate and protons in leachates from the litters and decreased calcium and magnesium contents of the leaves. However, there were few differences in the responses between leaf litters from the two woodlands. This was attributed to rapid sulphate wash-out from the litters from the heavily polluted woodland, so that the litters from the two sites quickly reached the same sulphate status.