Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 16. (Eger, 1997.)
SÓLYMOS,P.-NAGY, A.: The recent mollusc fauna of the szársomlyó (S Hungary): spatial pattern and microclimate
1997 16: 35-42 The recent mollusc fauna of the Szársomlyó (S Hungary): spatial pattern and microclimate P. Sólymos - A. Nagy Abstract: The recent mollusc fauna of the Szársomlyó (S Hungary) is discussed on the basis of 36 soil samples with equal volumes. This is the comparative study of 9 different biotopes of the hill, concerning molluscs, microclimate and the structure of the biotopes (rocks types, soil types, plant cover, and vegetational composition). Molluscan patterns are related with these factors so spatial pattern types and subtypes could be separated using the malacological records. Our microclimatological surveys are shortly discussed in this paper as well. 1. Introduction Previous works (Gebhardt, A. 1958, Kovács, Gy. - Richnovszky, A. 1989) to investigate the recent mollusc fauna of Szársomlyó have not been reflected the connection between molluscs and the characteristics of the different biotopes where they live. This paper shows the latest results added to the former study (Sólymos, P. 1997) considering the microclimatic and the biotope variations caused by several factors detailed below. 2. Study Area The Szársomlyó is situated in Villány Mountains (S Hungary), about 10 km N of the Hungarian-Croatian border. The climate of this region has a strong submediterranean character expressed in the annual temperature (10,9 °C) and in the ammount of precipitation (676-697 mm yr-1) with its two maximums (Marosi, S - Somogyi, S. 1990). The hill is built of Cretaceous limestone on the W part and Jurassic limestone on the E part. Their chemical features are quite the same but their physical features are very different, which causes dissimilarity in soil types and vegetation of the two parts. The vegetation is rocky grassland (Sedo sopianae-Festucetutn dalmaticae) on the W part and scrub (Imdo spiraeifoliae-Quercetum pubescentis) on the E part. The scrub is transitional on the S slope and closed on the N slope. There is closed forest (Aspendo taurinae-Carpinetum tilientosum argenteae and Helleboro odoro-Fagetam mecsekense) on the Pleistocene loess of the N slope. The vegetation of loess around the top is steppe grassland (Cleistogeni-Festncetum rnpicolae baranyaense) (Dénes, A., 1994, Kevey, B.1986, Lehmann, A. 1975). 3. Results 3.1. Microclimatological observations A former work (Horvát, A. O. - Papp, L. 1965) compared the microclimate of slopes of differing exposure: the S slope (rocky grassland), the N slope (closed forest) and the ridge. They stated that the rocky grassland has the most extreme microclimate. On the S slope air temperature, insolation, evaporation and wind speed are the highest and relative humidity is the lowest. On the N slope these are just the opposite and the ridge presents a transitional state.
