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

T and RH fluctuations of the different environments are quite the same at 2 m. At 0 m GRL has maximal and SCR has minimal T fluctuation (Fig. 3), GRL has maximal and RSL has minimal RH fluctuation (Fig. 4). Fig. 3. Schematic diurnal pattern of air temperature variation with hight: minimum and maximum curves. Legend is same as in Fig. 1. Fig. 4. Schematic diurnal pattern of relative humidity variation with hight: minimum and maximum curves. Legend is the same as in Fig. 1. 3.2. Expressing mollusc pattern Table 3. Main characteristics of the sampling areas. Areas Base rocks and sediments Vegetation and cover Exposure 1 Jurassic limestone Scrub-forest, closed N 2 Pleistocene loess Steppe grassland, open S 3 Cretaceous limestone Rocky grassland, open S 4 Pleistocene loess Forest, closed N 5 Jurassic limestone Scrub, transitional S 6 Jurassic limestone Scrub, transitional S 7 Jurassic limestone Steppe with rocks, open E 8 Jurassic limestone Scrub, transitional S 9 Jurassic limestone Rocky grassland, open S The investigation was carried out in 1996 and 1997. Table 3 shows the main characteristics of the 9 sampling areas (Figs. 5 and 6). Four equal volume soil samples (20 cm x 20 cm x 5 cm per quadrat where it was possible) were collected from each areas completed with thinning out. The selected malacological material was identified according to Kerney - Cameron - Jungbluth (1983) and Soós(1943). Ranging the 9 areas according to the basic data (Table 4) and considering the relative abundance ranks per area we can separate high, middle, and low abundance areas for each species. Represent these in a 3 x 3 squares we get spatial pattern pictograms. Concerning plant cover the closed group consists of Areas 1 and 4 exposed to the N. The transitional group consists of Areas 5, 6, and 8 exposed to the S. These Areas are mosaiclike scrubs often with pure rocks. The open group contains Areas 2, 3, 9 exposed to the S, and Area 7 exposed to the E. These are rocky or steppe grasslands. The groups are closely related with mollusc patterns (compare Figs. 6 and 8. and Table 3). Grouping the pictograms according to the cover we get pattern types and subtypes as shown in Fig.

8. The multivariate statistical procedures for grouping the areas according to mollusc species have the same result. We used Principal Coordinates Analysis (PCoA). We calculated the resemblances using Jaccard index because of our binary data. Fig. 7. shows that the areas can be separated into the groups mentioned above. The main groups are the same as Sümegi (1989, 1996) and Krolopp - Sümegi (1992) propounded in their works for palaeoecological investigations. Comparing the opinions there are differences in the grouping of some species. They mentioned i. g. Vallonia pulchella and Punctum pygmaeum as species belonging to the transitional group, in the present classification