Data from: Forest snail faunas from Transylvania (Romania), and their relationship to the faunas of Central and Northern Europe

Forty-three forest sites in seven sampling areas in mountainous parts of Transylvania were sampled to obtain inventories of their snail faunas, and to make comparisons between these and the faunas of similar sites further north along the Carpathian chain. Sampling areas ran from close to the Ukrainian border in the north to Retezat in the south-west. Altogether, 83 species were found, and between 19 and 40 species at individual sites. Sites within the same sampling area had more species in common than in among-area comparisons, but differences between areas did not relate to distance between them. Such differences appeared to relate more to ecological factors than to geography. Faunas of all areas were very similar to those recorded from the Polish and Ukrainian Carpathians; distance from these northern faunas had little effect on similarity. More broadly, the fauna of these forests shows much greater affinity to those of countries to the north than to those of countries to the south. Despite the survival of forests through the last glacial period of the Pleistocene, and the greater proximity to potential Mediterranean refugia, these faunas appear to be mainly a subset of those found further north. They represent a rather small proportion of the known Romanian fauna, in which there are many endemics restricted to other habitats.