Hidrológiai Közlöny, 2014 (94. évfolyam)
2014 / 5-6. különszám - LV. Hidrobiológus Napok előadásai
81 AbstractiLake Stechlin lies in Germany, on the southern boarder of the Mecklenburg Lake District. Recently, less research has focused on diatoms of the oligo-meso- trophic lake - contrary to phytoplankton studies. The aim of this study was to assess the current composition of benthic diatom communities of the lake and to estimate the trophic level based on TI diatom index. Phytobenthos samples were taken on 3 May 2013 from 23 different sites of the littoral zone of the lake from natural stone substrate. Species composition was determined with light and electron microscopes altogether, 70 species were found. Number of species (29±3), Shannon-Wiener diversity (2,36±0,23), evenness (0,70±0,06) did not show any diffemces between the sampling sites. Diatom communities of the littoral region showed an uniform picture, there was not considerable difference in the three basins of the lake. Eutrophic species were dominant (e.g. Cymbella compacta, Diatoma moniliforme, Fragilaria capucina var. vaucheriae, Nitzschia dissipata, Rhoicosphenia abbreviata, Gomphonema olivaceum, G. pumilum) and planctonic Centrales species (Stephanodiscus minutulus, S. neoastraea). We also found the dominance of some cosmopolitan species (Achnanthidium mi- nutissimum, Cocconeis placentula var. euglypta, Diatoma ehrenbergii) and broad tolerant species like Amphora pediculus. Trophic level of the lake was estimated with TI diatom index developed for German lakes, based on the index values the lake was eutrophic at each sampling sites. In the water samples low concentration of N and P forms were found - in contrast to the TI index - indicating mesotrophic state of the littoral zone. Keywords: oligotrophic, littoral region, stone substrate, diatom community, TI diatom index. 1. Amphipleura pellucida (Kützing) Kützing 2. Cymbella helvetica Kützing 3. Encyonema prostratum (Berkeley) Kützing 4. Encyonema caespitosum Kützing 5. Cymbella excisa Kützing 6. Encyonema silesiacum (Bleisch) D.G.Mann 7. Cymbella compacta 0strup 8. Stephanodiscus neoastraea Hákansson & Hickel 9. Stephanodiscus minutulus (Kützing) Cleve & Möller 10. Cyclotella ocellata Pantocsek 11. Diatoma ehrenbergii Kützing 12. Diatoma tenuis C.Agardh 13. Fragilaria capucina var. vaucheriae (Kützing) Lange-Bertalot 14. Fragilaria brevistriata Grunow 15. Staurosira venter (Ehrenberg) H.Kobayasi 16. Nitzschia dissipata (Kützing) Grunow 17. Nitzschia palea (Kützing) W.Smith 18. Nitzschia dissipata var. media (Hantzsch) Grunow 19. Nitzschia recta Hantzsch ex Rabenhorst 20. Ulnaria ulna (Nitzsch) P.Compére 21. Achnanthidium minutissimum (Kützing) Czamecki 22. Encyonopsis subminuta Krammer & E.Reichardt 23. Aneumastus minor Lange-Bertalot 24. Reimeria sinuata (Gregory) Kociolek & Stoermer 25. Karayevia clevei (Grunow) Bukhtiyarova 26. Amphora pediculus (Kützing) Grunow ex A.Schmidt 27. Cavinula scutelloides (W.Smith) Lange-Bertalot 28. Gomphonema pumilum (Grunow) Reichardt & Lange-Bertalot 29. Gomphonema olivaceum (Homemann) Brébisson 30. Gomphonemaparvulum (Kützing) Kützing 31. Gomphonema truncatum Ehrenberg 32. Gomphonema pala E.Reichardt 33. Gomphonema acuminatum Ehrenberg 34. Cocconeis placentula var. euglypta (Ehrenberg) Grunow 35. Cocconeis pediculus Ehrenberg 36. Navicula cryptotenella Lange-Bertalot 37. Navicula capitatoradiata Germain 38. Navicula reinhardtii Grunow 39. Navicula tripunctata (O.F.Müller) Bory de Saint-Vincent in Bory de Saint-Vincent 40. Navicula reichardtiana Lange-Bertalot 41. Navicula antonii Lange-Bertalot 42. Navicula dementis Grunow 43. Rhoicosphenia abbreviata (C.Agardh) Lange-Bertalot 1. fotótábla: A Stechlin-tóban talált néhány kovaalga faj 1. Dhoto table: Some diatom SDecies found in Lake Stechlin
