L. Hably szerk.: Studia Botanica Hungarica 23. 1992 (Budapest, 1992)

Papp, Beáta: Phytocoenological survey along the Koloska stream (Balaton-felvidék region, Hungary)

STUDIA XXIII. BOTANICA HUNGARICA (Antea: Fragmenta Botanica) 1992 pp. 81-95 Phytocoenological survey along the Koloska stream (Balaton-felvidék region, Hungary) By B. PAPP (Received October 30,1990) Abstract: Investigation of the effects of karstwater decrease on the structural and abundance relations of vegetation types supplied by the Koloska karst stream was carried out. This study is a baseline survey in this valley and a few years later it may serve as a standard for the comparative investigations and phytoindication of karstwater level changes. Information about the water supply of the riparian vegetation and the disturbing effects can be obtained on the basis of the W (water requirement) and NC (nature conservation) spectra of the stands of communities. INTRODUCTION In recent years the karstwater level in the Transdanubian Central mountains has noticeably decreased due to mine-water extraction. Between 1978 and 1984 the decrease rate was 1-2 m per year in this region. Karstic springs at higher elevations dried off and the water output of lower beds has also decreased. At the Department of Plant Taxonomy and Ecology of Eötvös Loránd University investigations on the effects of karstwater decrease on the structural and abundance relations of vegetation types supplied by karst streams have been initiated. The present study is connected with these examinations. There was no earlier botanical survey of the Koloska valley before, so this study provides a basic record and in a few years can serve as a standard for comparative investigations and phytoindication of karstwater level changes. MATERIALS AND METHODS The Koloska valley is situated in the southwestern part of the Balaton-felvidék region of the Transdanubian Central mountains (Fig. 1). The valley opens 2 km from the Balaton lake, near Balatonarács. The direction of the valley at the beginning is north-south, further it becomes northwest-southeast. The distance