B. Papp szerk.: Studia Botanica Hungarica 33. 2002 (Budapest, 2002)
Dobolyi, Konstantin: Studies of vegetation dynamics on the rock grasslands in Csíki-hegyek (Budaörs, Hungary)
Studia bot. hung. 33, pp. 83-96, 2002 STUDIES OF VEGETATION DYNAMICS ON THE ROCK GRASSLANDS IN CSÍKI-HEGYEK (BUDAÖRS, HUNGARY) K. DOBOLYI Department of Botany, Hungarian Natural History Museum H-1476 Budapest, Pf. 222, Hungary; E-mail: dobolyi@bot.nhmus.hu Based on 20 phytosociological relevés studied during a five-year period, changes of vegetation of dolomite grasslands have been investigated. The following characteristics were analysed: phytogeographical area (floral element), phytosociological character, social behaviour type, degree of naturalness and indicator value of the nitrogen preference. Degradation of the grasslands has been documented and certified. With 9 tables and 1 figure. Key words: dolomite grasslands, ecological indicator values, phytosociology, social behaviour types, vegetation dynamics INTRODUCTION Dolomite as parent material occurs in large areas of the Hungarian Central Mountains. Physical and chemical characteristics of this bedrock are expressed in the peculiar geomorphological appearance of the dolomite hills; these characteristics have a strong influence on the flora and vegetation (ZÓLYOMI 1942). Early description and characterisation of rock grassland vegetation were made by ZÓLYOMI (1936, 1966). Vegetation of the Pannonian dolomite hills has been in focus of interest of botanists for a long time. Dolomite vegetation of Balaton Upland was analysed phytosociologically by DEBRECZY (1966, 1973). Vegetation mapping of the Odvas-hegy and its grassland vegetation was investigated (DOBOLYI et al. 1991). Variability, compositional diversity and fine-scale spatial patterns of dolomite grasslands were studied (KUN 1996, BARTHA et al. 1998, KUN et al. 2002), numerical analysis of dolomite rock grassland was carried out (PODANI 1998). The recently accepted classification of dolomite plant communities is given in BORHIDI (1996) and BORHIDI and SÁNTA (1999). One of the largest dolomite-dominated areas of Hungary is Csíki-hegyek, found in the southern part of Buda Mts (9 km SW of Budapest). The main bedrock of this area is Triassic diplopore dolomite. Since the surroundings of Csíki-hegyek have been inhabited for hundreds of years, the present state of vegetation is determined by consequences of human activity. Description of the supposed original plant cover is given in ZÓLYOMI (1958). The most important plant communities of Csíki-hegyek were 1) xerotherm oak forests (closed thermophilous oak woodlands), 2) mixed relict oak woodlands on
