B. Papp szerk.: Studia Botanica Hungarica 30-31. 1999-2000 (Budapest, 2000)

Csontos, Péter, Lőkös, László; Molnár, Katalin: Numerical analysis of lichen zones in Komárom, NW Hungary

this is that trees are found both in the built-up area and outside the settlement (certainly with different frequency), whereas stones or stone-like surfaces are found in the built-up area only. Therefore, epiphytic lichens could perform their habitat preferences in the whole study area, while the saxicolous ones were restricted to the built-up areas. The other reason may be that the saxicolous lichens tolerate more air pollution, consequently, they are distributed rather evenly among the sampling sites with stony substrates. When subgroups of the sampling sites with mainly epiphytic lichens were re-allocated to the map of Komárom and its surroundings, a fairly good coincidence occurred between the distribution of the two subgroups and the visually established boundary of the two "struggle zones" of the lichen map. Thus the existence of an inner and an outer "struggle zone" is clearly supported by the numerical multivariate analyses. In correspondence with previous surveys by several investigators (HAWKSWORTH and ROSE 1976, KIRSCHBAUM and WlRTH 1997), in our study also the epiphytic lichens proved to be better for construction of air pollution maps. * * * Acknowledgements - We are indebted to Dr EDIT FARKAS (MTA ÖBKI, Vácrátót) for the valuable advice and discussions on the earlier draft of the manuscript. This work was supported by the Hungarian Scientific Research Fund (OTKA Nos T029784 and T030209). Many thanks are due to Dr ISTVÁN RÁCZ (MTM Növénytár, Budapest) for the linguistic corrections. REFERENCES ALMBORN, O. (1943): Lavfloran i Botaniska trädgarden i Lund. (The lichen flora of the Botanical Garden of Lund.) - Bot. Not. 1943: 167-177. BARBALIC, L. J. (1953): Raspored epifitskih lisaja u Zagrebu. (Verteilung der Epiphytenflechten in Zagreb.) - GlasnikBiol. Sekc. Hrv. Prirodosl. Durst., Ser. II/B 7: 99-100. ERNST, G. (1997): Die Flechten des Landkreises Harburg. - Ber. Bot. Vereins zu Hamburg 17: 1-136. FARKAS, E. (1982): Légszennyeződést vizsgálatok Budapest területén zuzmó-bioindikátorokkal. M. Sc. Thesis, ELTE Növényrendszertani és Ökológiai Tanszék, Budapest, 91 pp. FELFÖLD Y, L. (1942): A városi levegő hatása az epiphyton-zuzmóvegetációra Debrecenben. [The effect of the city air on the epiphytic lichen vegetation in Debrecen.] - Acta Geobot. Hung. 4: 332-349. FENTON, A. F. (1960): Lichens as indicators of atmospheric pollution. - Ir. Natur. J. 13: 153-159. GALLÉ, L. (1979): Wirkung der Luftverunreinigung auf die Verarmung der Flechtenvegetation der Stadt Szeged und ihrer Umgebung. - Acta Biologica (Szeged), 25(1-2): 3-15.