QUANTITATIVE BIOGEOGRAPHIC CHARACTERIZATION OF HUNGARY BASED ON THE DISTRIBUTION DATA OF LAND SNAILS (MOLLUSCA, GASTROPODA): A CASE OF NESTEDNESS OF SPECIES RANGES WITH EXTENSIVE OVERLAP OF BIOTIC ELEMENTS

Biogeographic classifications of Hungary in past decades were based on qualitative data, and since than, data have increased significantly and more efficient methods become available. I used UTM based distribution data of 121 land snail species to quantitatively assess biogeographic patterns in Hungary. Hierarchical cluster analysis identified two main clusters of areas: highlands and lowlands. This dichotomy can be attributed to mainly climatic and altitudinal differences. One fourth of the species were present in the whole country (general species), one fourth was characteristic to highlands, and half of the species (including all the endemics) were localized in smaller regions. The distribution of localized species revealed historical effects in regional faunas: Carpathian influences in the Northern Mountains, Alpine influences in the Western Marginal Area, and southern-Illyric influences in Southern Transdanubia. Biotic element analysis revealed that clustering of species ranges did not differed significantly from the null model, but species' areas were significantly more nested that under the null model. Based on the high degree of nedtedness in species' areas and the composition of various biogeographical influences, representativeness can be achieved with relative efficiency in Hungary.