Rich molluscan assemblages occur in the Upper Holocene sediments of the Pasternik stream at Czorsztyn and in limestone soils on rocks at the castle of Czorsztyn. The older assemblagę found in the muds of the upper terrace comprises a fauna with a big share of forest snails whereas the younger assemblage comes from the sediments of the lower terrace and contains mostly typical species of the open environment. The change of fauna is due to the deforestation of the catchment basin of the stream, which took place in the 13th and 14th centuries. In the initial limestone soil there are very numerous snail shells representing various ecologic groups and the diversification of the assemblages reflects the mosaic pattern of their habitats, which were being slightly changed by human impact.