World Congress of Malacology Antwerp ... - Unitas Malacologica

of the Balcan peninsula (excluding Greece and Turkey) are almost unexplored. Here we present data
from 24 sites (10 countries) that - although suffering from variable sampling intensity - might fill in
this gap. According to the generalized linear models, two polynomial terms of latitude and longitude
explained 40% of the total variation of species richness, while effect of altitude and clustering of the
sampling sites based on faunal similarities was not significant. This indicates a gradual decrease of
species richness in beech forests towards south and west, which can be due to warmer climate.
Richness was highest in the Carpathian region with Clausiliids comprising 40% of the regional
species pool. Species composition - opposed to richness - changed abruptly between the identified
main zoogeographical cluster of the sites (Albanicum, Illyicum, Moesicum, western and eastern part
of the Carpathicum, following traditional terms). Species turnover was almost complete in 500 km
distance (80-100% Jaccard distance). Although this turnover rate may be overestimated by 10-15%
because of the exclusion of widespread microsnails (