The lichen- and bryoflora in two man-made areas (sedimentation basins serving for mining waste disposal, and industrial ash-slag disposal, respectively) near the power stations in Chvaletice and Opatovice (Bukovina locality) (both in E Bohemia, the Labe-River lowland) have been surveyed.The main sampling occurred from 1994 to 1999.Three additional collecting visits to the former locality were conducted in 2000 and 2002. Seemingly poor, in parts almost desert-like, landscape of the two dried sedimentation ponds surprisingly hosts remarkable numbers of lichens as well as bryophytes. In total, 103 taxa of lichens and 51 taxa of bryophytes were recorded (Chvaletice: 99 lichen and 46 bryophyte taxa; Bukovina: 15 lichen and 19 bryophyte taxa). Most of these species have quite a broad ecological amplitude, however, some of them appear to be almost ruderal specialists, so far known from urban habitats only.Toxicity of the substrate and extreme climatic conditions in both localities are supposed to be the controlling agents supporting expansion of bryophytes and lichens and retarding the fast development of vascular plant communities. Instability of the substrate and a much lesser amount of tipped extraneous material in the Bukovina sedimentation basin resulted in a higher proportion of bryophytes to lichens than in the Chvaletice sedimentation basin. Four lichens, Bacidina egenula, Caloplaca flavocitrina, Cladonia humilis and Verrucaria simplex are reported for the first time from the Czech Republic. Keywords: Anthropogenic substrates, bryophytes, colonization, lichenized fungi, pioneer vegetation.