Ábrahám Levente: Válogatott tanulmányok II. - Natura Somogyiensis 9. (Kaposvár, 2006)

Dénes Andrea - Ortmanné Ajkai Adrienn: A Dráva baranyai holtágai 2. Vegetáció-térképek - Oxbow lakes of river Drava in Baranya county (South Hungary) 2. Vegetation maps

38 NATURA SOMOGYIENSIS Oxbow lakes of river Drava in Baranya county (South Hungary) 2. Vegetation maps ANDREA DÉNES & ADRIENN ORTMANNÉ AJKAI Youngest and largest open-water oxbow lakes of plain of Drava were created artificially by cutting big meanders during controlling of the river. Vegetation maps of eight big oxbow lakes in county Baranya were made in year 2000 using aerial photographs (Mrtvica near village Felsőszentmárton; Bresztik, Vájás-tó, Zalátai O-Dráva near village Drávasztára; Fekete-tó near village Zaláta; Piskói-tó (Versági-tó) near village Piskó; Hótedra, Matty

i-tó near village Gordisa). Among treeless communities open-water floating, submersed and rooting water-weed communities occur in great numbers. Concave sides of oxbows, filling up more quickly are bordered by wide reed communities, most interesting is Phragmitetum communis thelypteridetosum palustris which shows moor characteristics. Willow groves (Leucojo aestivi-Salicetum albae) occur almost everywhere, somewhere smaller poplar groves occur too. Moor-like woody communities Calamagrostio-Salicetum cineraeae or moor-like Salix cinerea stands - can be found on deeper convex sides of the oxbows but sometimes occupies larger areas in the reed belts of concave sides too. Greatest moving moor {Thelypteridi-Typhetum angustifoliae) of Drava plain can be found in oxbow Hótedra. Protection zone of natural vegetation is missing at most mapped oxbow lakes: usually they are bordered directly by cultivated fields, and most of them are used as angler lakes, with all of its damaging effects.