World Congress of Malacology Antwerp ... - Unitas Malacologica

familial, generic and species) within the phylogeny. Such a functional approach to the study of
developmental sequences has highlighted the possibility that heterochrony may have played a
prominent role in the evolution of this group of invertebrates. Current studies are expanding
phylogenetic coverage to include the influence of habitat shifts (i.e. freshwater to marine) and
convergence (in “limpet” forms) on developmental sequences.
Regional and local scale effects on the richness and composition of land snail assemblages in
Hungary
Sólymos, Péter 1 ; Jónás, Ágota 2
1. Department of Ecology, Faculty of Veterinary Science, Szent István University, Rottenbiller Str.
50, 1077 Budapest, Hungary,
Email: Solymos.Peter@aotk.szie.hu
2. Department of Evolutionary Zoology, University of Debrecen, Egyetem Sqr. 1, 4032 Debrecen,
Hungary
Richness and composition of local assemblages is influenced by both local and regional scale effects,
but relative influences of these factors are little known. Here we used published occurrence data of
103 land snail species from 210 sites in Hungary. Sites were classified according to vegetation
structure (forested, unforested), moisture (dry, moist), and geographical regions (Great Plain,
Transdanubian hills and mountains, and Northern Mountains). We used general linear models,
univariate and multivariate regression tree analyses. The best fit linear model for the determinants of
local species richness contained the interaction of region and moisture. Richness was lowest in the
Great Plain, intermediate in dry habitats of Transdanubia and the Northern Mountains, highest in
moist Transdanubian sites, and significantly the highest in moist habitats of the Northern Mountains.
Regression tree analysis revealed similar results, region was most important, richness being lowest in
the Great Plain. The split within localities of Transdanubia and the Northern Mountains was best
explained by moisture, with lower richness in dry sites. Third split within moist sites was according
to region, again: richness was higher in the Northern Mountains (especially in forests) than in
Transdanubia. According to multivariate regression tree, species composition was determined
primarily by vegetation, secondarily by region. Moisture was important in Transdanubia and the
Northern Mountains in forested and unforested habitats as well. Our results indicate that species
richness reflects primarily geographical (regional scale) constraints on the dispersal of species and
secondarily responses to a moisture gradient. Species composition is determined primarily by local
factors, i.e. vegetation, through species-sorting and secondarily by regional constraints. This research
was supported by the Hungarian R&D program No. 3B023-04 and Hungarian Scientific Research
Fund (OTKA T 043508).
Geographical variation in the richness and composition of forest snail faunas in central and
southeast Europe
Sólymos, Péter 1 ; Erőss, Zoltán Péter 2 ; Šteffek, Jozef 3
1. Department of Ecology, Faculty of Veterinary Science, Szent István University, Rottenbiller Str.
50, 1077 Budapest, Hungary,
Email: Solymos.Peter@aotk.szie.hu
2. Bem Str. 36, 1151 Budapest, Hungary,
Email: erosspeter@hotmail.com
3. Institute of Forest Ecology, Slovak Academy of Sciences, Štúrova 3, Zvolen, Slovak Republic,
Email: steffekjozef@yahoo.com
Recent efforts have made towards an understanding of diversity and composition of land snail faunas
on a wide array of locations and geographical scales. In Europe, northwestern and Mediterranean
areas are relative well explored, but areas south to the Northern Carpathian mountain chain and areas
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