A Veszprém Megyei Múzeumok Közleményei 12. (Veszprém, 1973)

Dr. Debreczy Zsolt: A Balaton-felvidéki Péter-hegy és környéke cönológiai vizsgálata

mediterranische Charakter der Gesellschaft gekennzeichnet (16%). Dadurch schliesst sie sich aber nicht an die zu Fagion illyricum gehörenden Helleboro (dumetorumj- Carpinetum und Asperulo taurinae-Carminetum Gesellschaften an, die mit den mesofilen Waldarten einen submediterranen Charakter bilden, da hier 77% der submediterranen Arten von den umgebenden Eichenwäldern eingewanderte Quercetea Elemente sind. Die Arbeit bespricht weiterhin kurz die QUERCEThe present study discusses one of the best preserved vegetation settled on chalk and dolomite in the Balaton upland. The geology, climate and pedology of the region are treated on the basis of literature, but to further enlarge knowledge on the vegetation conditions the author adds the result of his own analysis obtained in this region. The vegetation has been studied on a comparatively small area but is based on several hundred surveys according to succession, detailed analysis is made starting with the open saxatile grass communities right up to the climax associations, and this is done with the help of area type, cenological group, TWR value and relative coefficients. The area under investigation is on the northern shore of Lake Balaton and it is the first range of mountains between Balatonfüred and Csopak and those adjacent areas lying closely behind them. Its highest points are 317 m (Tamás-hegy) and 315 m (Péter-hegy), this range rises by some 150—200 m above Lake Balaton (106 m). Its geological structure is varied: Triassic layers settled on Permian red sandstone - the lower starts with Triassic laminated dolomite, the upper finishes with Triassic main dolomite (BÖCKH 1913, LÓCZY 1917, LÁNG 1958; Fig. 1). On the SE slopes the Triassic layers come on the surface at a wide crack as a basset on which Pannonian (Pontian) layers and loess have settled. The erosion of young layers brought the Megyehegy dolomite on the surface over large areas and here on the skeleton solum of the SE slopes xerotherm association developed. It is characteristic for the climate that the western. Atlantic currents drop their moisture content at the 400—600 m Bakony Mts. before the Balaton upland, thus these currents arrive at the lake only as a drying foehn (STEFANOVITS 1963, p. 301). In the summer half-year, decisive for the vegetation of the temperate zone, here less than 350 mm precipitation falls with an expressed semi-arid period, while only some 30 km in beeline in the westerns part of the Bakony Mts. 400— 450 m. This climatic difference within this short extensive distance has drastic effects in its zonality: the zonal beech woods in the Bakony Mts. here are replaced by large Ото-Quer cetum areas (FEKETE and ZÓLYOMI 1967, DEBRECZY 1968). Beech is entirely missing even from the narrowest of valleys or if present occurs but singly. In the given climate on the denuded deep or shallow but both water conducting skeleton solums intrazonally open saxatile or closed grass associations occur TUM-PETRAEAE-CERRIS Bestände, die in der Übergangszone zwischen Orno-Quercetum und Querco-Carpinetum auftreten sowie die Carex alba Flecke mit einem Reliktcharakter, wo auch Veronica officinalis und Melampyrum pratense an den kleinen sauren Flekken auftreten. Diese Arten befinden sich übrigens niemals auf einem Kalkstein-Gebiet, ihre Expansion zu diesem Gebiet ist auf vegetationsgeschichtliche Gründe (atlantische Phase) zurückzuführen. Zsolt Debreczy and on the outwashed, eroded outcrops various species of lichens grow. On the more water reserving rendzinas Cotino-Quercetum scrub forests are formed with steppe mosaic patches in between. The zonal association (Or no-Quer cetum) is found on lime and dolomite areas, clayey rendzinas, hangmoor loess, braunerde, clay lessivated brown forest soil, brown forest soil with carbonate remnants. (Only two small relic patches are situate on acidic soil (pH 5.15) with Carex alba, Melampyrum pratense, Veronica officinalis.) This area has been investigated floristically by such eminent scientists like KITAIBEL (1799), SADLER (1842), BORBÁS (1900), BERNÁTSKY (1907) went even further and he already dealt with formations, too. The first cenological data originate írom SOO (1928—1930— 1940). The xerotherm grasses (Chrysopogono-Caricetum humilis balatonicum) have been ranged after ZÓLYOMI (1967) among the sub-Mediterranean group (Bromo-Festucion pallentis). Its three subassociations 1. minuartietosum substitutes the Seseleo-Festucetum glaucae common in the Transdanubian Central Mts. open saxatile grasses. It developed on dolomite but lacks the charasteristic species. Assumptions suggest that the top of the Megyehegy dolomite had been exposed later than when the expansion of the dolomite species took place in the Atlantic-boreal transitional phase (DEBRECZY 1966), thus, these species could not settle and their place was taken by closed lime saxatile grass species forming a characteristic open association. Its closed variety is 2. botriochloetosum. While the last group is 3. brometosum subassociation forming a closed grass association among the northerly exposed limestone. When the slope steppes of the Balaton upland have been conspered with the asszociations farther North of the Buda-Mountains it has become evident that the ratio of the Pontian elements representing continentality dropped from 20% (Buda Mts.) to 13%, while an increase has been noticed in the sub-Mediterranean species from 11% to 24%,. Scrub forests (Cotino-Quercetum pubescentis balatonicum) are thin, generally occurring in a few metres diameter of forest patches on shallow rendzina soil. It is a stable "state" between forestation and grass associations which are maintained by the prevailing environmental factors. The vegetatively expanding mass of Cotinus coggygria over a large area of the Central Mts. is a common feature, which appears as a lower scrub THE COENOLOGICAL INVESTIGATIONS OF PETER-HEGY (MOUNTAIN) AND ITS ENVIRONS IN THE BALATON UPLAND 219