Alte Teichlandschaften im österreichischen Waldviertel: Vegetation und Diasporenpotential des Schönauer Teiches bei Zwettl Von Marcus Koch, Karl-Georg Bernhardt, Josef Webhofer und Monika Kriechbaum Mit 2 Abbildungen und 4 Tabellen Abstract Koch, M., Bernhardt, K.-G., Webhofer, J. & Kriechbaum, M.: Alte Teichlandschaften im österreichischen Waldviertel: Vegetation und Diasporenpotential des Schönauer Teiches bei Zwettl. [Ancient ponds in Austria: Vegetation and soil seed bank of the Schönauer Lake near Zwettl, Waldviertel.] — Bot. Jahrb. Syst. 126: 133–147. 2005. — ISSN 0006–8152. The north western Waldviertel in Lower Austria, close to the border of the Czech Re- public, is well known for its extensive fishery since the 16 th century. The traditional land use and fish pond management with regular de-flooding and periodical oscillations of the water level has resulted in the establishment of characteristic reed and pioneer vegetation along shore lines and unflooded pond grounds. During the investigation period from 2000–2002 we analysed the vegetation and found numerous europe-widely endangered plant species (Coleanthus subtilis, Limosella aquatica, Elatine triandra, Elatine hexapeta- la, Elatine hydropiper , Spergularia echinosperma, Eleocharis ovata, Carex bohemica or Scirpus radicans). Moreover, several rare and characteristic mosses were documented, such as three Riccia species. The remarkable dynamics of the habitat are favouring evolu- tion and speciation processes, and several hybrid swarms from the genus Carex (C. vesi- caria, C. rostrata, and C. gracilis, C. nigra) were documented. A special focus is given here on the soil seed bank for two reasons: it is important for the recruitment of new genera- tions and its long persistence and longevity has implications for nature and species con- servation efforts. All species from the actual vegetation could also be found in the soil seed bank, which exhibited densities from 104.000 to 1.447.000 seeds/m². Keywords: Coleanthus, Eleocharito-Caricetum bohemicae, fish ponds, soil seed bank. Bot. Jahrb. Syst. 126 1 133–147 Stuttgart, 28. Februar 2005 DOI: 10.1127/0006-8152/2005/0126-0133 0006-8152/05/0126-0133 $ 03.75 © 2005 E. Schweizerbart’sche Verlagsbuchhandlung, D-70176 Stuttgart