B. Papp szerk.: Studia Botanica Hungarica 33. 2002 (Budapest, 2002)

Buczkó, Krisztina: A new floristical survey of the algal flora of the Babat valley, Hungary

Studio bot. hung. 33, pp. 5-20, 2002 A NEW FLORISTICAL SURVEY OF THE ALGAL FLORA OF THE BABAT VALLEY, HUNGARY K. BUCZKÓ Department of Botany, Hungarian Natural History Museum H-1476 Budapest, Pf. 222, Hungary; E-mail: buczko@bot.nhmus.hu During a recent algological survey, carried out in 2001 at 6 small ponds of the Babat valley near Gödöllő, central Hungary, 209 taxa were recorded, of which 122 are new records. Two of the ponds are semi-natural, in these we identified 65 and 91 algae, respectively. Adjacent to the shore of two other ponds goose breeding is going on, with 56 and 41 taxa recorded in these manure-polluted ponds. The polluted water from these ponds runs directly to two further (lower) ponds, with 85 and 66 taxa identified, respectively. Several diatoms appear to be new for the flora of the Babat farm, which is attributed to the methodological differences between an earlier study and the recent survey. Surprisingly, Cylindrospermopsis raciborskii, the very common, toxic cyanobacteria, was found only in one, semi-natural pond having a unique, diverse alga flora. Chara canescens was found in the upper pond in the spring. Key words: algal flora, Babat valley, nature conservation INTRODUCTION The Babat valley, with the Aranyos stream flowing through it, is situated near Gödöllő, central Hungary (Fig. 1). Between 1930 and 1940,11 dams were built to create a number of small ponds. The algae of the Babat valley have attained special significance of algologists and hydrobiologists in Hungary. At the end of the sixties and the beginning of the seventies Lajos Hajdu conducted here a case study for developing and the application of new statistical methods, e.g. diversity indices and cluster analyses. He examined the phytoplankton in two "fishponds" ("No. 8" and "No. 10" in his work) month by month during the year of 1969. At that time both ponds were 2.0-2.5 m deep at their deepest point, their surface was around 2 hectares each. During his qualitative analyses 191 algae taxa were identified, but with accessory investigation the number of taxa increased to 229. His results were presented in several publications (HAJDU 1974,1976,1977a, b, 1978a, b). Further reports with new data were published by HEGEWALD et al. (1975, 1981). The present work is part of a new botanical and zoological survey of the Babat valley organised by the Institute of Environmental Management of Szent István University in 2001 and aimed at compiling a record of the algae living in the ponds, and to estimate the diversity of this flora. Here we provide a floristical overview based on the investigation conducted in 2001.