The interest in dead wood ecology has increased the last years. There have been many studies made on lichens on woody substrates of conifers in boreal forest, but this is the first study on the lichen flora on woody substrate in broad-leaved deciduous forest. In this study the lichen flora was inventoried on 30 decorticated logs of Wych elm, Ulmus glabra in three areas close to Ekoln bay in lake Mälaren South of Uppsala. Totally 36 lichen taxa and one non-lichenised fungus were recorded. According to literature 47 % of these lichen species were earlier not known as lignicolous. The study showed that the number of taxa increased with distance to the log base and decreased with measured log diameter. The highest diversity was found on logs in...