L. Hably szerk.: Studia Botanica Hungarica 23. 1992 (Budapest, 1992)
Buczkó, Krisztina; Ács, Éva: Preliminary studies on the periphytic algae in the branch-system of the Danube at Cikolasziget (Hungary)
STUDIA BOTANICA HUNGARICA (An tea: Fragmenta Botanica) XXIII. 1992 pp. 49-62 Preliminary studies on the periphytic algae in the branch-system of the Danube at Cikolasziget (Hungary) By K. BUCZKÓ and É. ÁCS (Received December 11,1991) Abstract: Altogether 179 periphytic algal taxa were identified from the branchsystem of the Danube at Cikolasziget, from different hosts (twig, reed, and other macrophytes). We found that water temperature, shadiness and water discharge affect the composition of the periphyton. According to the species composition of our samples, the number of taxa and the structure of the periphyton show a transitional character between the periphyton of standing and flowing waters. INTRODUCTION The Danube entering the Carpathian Basin divides into many smaller branches. This region is called Szigetköz and Csallóköz. Nowadays most of the small branches are separated from the main branch by dams. The branch-systems of the Danube in the area of Szigetköz and Csallóköz are not only among the most beautiful landscapes of Hungary but a unique natural heritage of Europe and even of the World. This wonderful part of the Danube is threatened by the hotly debated dam at Bős. It is a very urgent task of Hungarian science to possess better knowledge on the plants and animals living there. We have only few algological data on the phytoplankton of the Szigetköz (BARTALIS 1978, 1982,1987a, KISS 1987) especially compared with the main branch of the river (e.g. BARTALIS 1987b, BOTHÁR and KISS 1990, HEGEDŰS 1987, HORTOBÁGYI 1979, KISS 1984, SCHMIDT 1976, SZEMES 1967, TAMÁS 1949) but we failed to find any publication on the attached algae of this region. The many branches, the sometimes slowly and sometimes quickly flowing or even standing water, the different kinds of submersed macrophyte associations presumable favour the development of very different periphytic communities. Therefore our purpose was to know more on the algological periphyton of this region. The first and evident question of the periphytic studies is whether on the different submersed objects and plants (namely substrate) the periphyton is the same or not. However, we have no satisfying answer to this. Many papers report the uniformity of periphyton, i.e. there are no differences between the algae living on the different substrates (e.g. MILLIE and LOWE 1983, O'QUINN and SULLIVAN 1983, SULLIVAN 1982). Perhaps more publication deal simultaneously with the
