Terrestrial gastropods of the nature reserve Stary Zagaj and the town of skępe (dobrzyńskie Lakeland). The malacocoenosis structure as an indicator of anthropogenic influence in north-central Poland

Thirty nine species of terrestrial gastropods were recorded from the little studied Dobrzyńskie Lakeland (north-central Poland): the nature reserve Stary Zagaj and the town of Skępe (30 from the nature reserve, 27 from the town, 18 species in common, 9 town only, 12 reserve only). The number of species per site ranged from 8 to 21 (mean 13.88), the number of specimens from 38 to 1,224 (mean 347.7). The aim of the inventory was to fill the gaps in the distribution knowledge and to identify symptoms of anthropogenic influence on the malacocoenoses. Most species were euryoecious and/or widely distributed. The results were compared to other biogeographically and ecologically similar, but mostly less humanaffected areas. The studied habitats showed unbalanced dominance structure, small between-site similarity and small proportion of forest-dwellers, combined with the near-absence or absence of clausiliids and other tree-climbing and/or timber-dependent species. These seem to be crucial symptoms of anthropogenic changes in effect at present or in the past. KEy words: gastropods, nature reserve, N-C. Poland, anthropogenic influence