Abstract:Recently, the number of alien landscape species has dramatically increased, and this could be a serious threat, not only for native species but also in cases of outbreaks for farmers. Our objective was to examine the impact of the urban environment (positive or negative) on the diversity of native species; forecast biotic homogenization or diversification of urban fauna; and determine the extent to which each of the zones are affected by invasive species. To examine the effect of urbanization, we selected 16 areas ( across three urban zones and one zone in the protected area for comparison) for this study in 2015 in Nitra. We found that snails in open locations had significantly greater species diversity and abundance of individuals than in closed locations. Slightly degraded areas had the most abundant snail species, but areas heavily disturbed had high species diversity and incidence of individuals. It appears that heavily disturbed areas are suitable as new types of refuge for snails, e.g., for Helix lucorum (Linnaeus, 1758), which was recorded in Slovakia for the first time (numerically recorded at the railway station) in 2014. UDC Classification: 591, DOI:http://dx.doi.org/10.12955/cbup.v4.766

In last decades, the number of non-native land snails increased up to 15 percentages; they create more than eight percent of all the Slovakian species. Trend of newly established snail species corresponds with increases in the average temperatures as well as the intensity of foreign trade, suggesting a synergistic effect of both climatic conditions and socioeconomic factors. The research of the open-air garden centres in Slovakia confirmed both factors. We report here some of the newly established populations of sixteen mollusc species. In the old garden centres, the number of species as well as the number of individuals decreased slightly. Area of the garden centre has a very high impact on both abundance and species diversity. The size and age of garden centre proportionally influences the composition of mollusc assemblages. Two new species Cornu aspersum and Cepaea nemoralis were noticed for the first time in Slovakia. The recent findings of the introduced populations demonstrate the potential of this snail to colonise new areas.

A malacozoological survey of the molluscan fauna in 21 selected wetland habitats was carried out in the White Carpathian Mts. in 2010–2014. In total, 66 species of gastropods (5 aquatic) were confirmed at the surveyed sites. Viable populations of two species of European importance were confirmed (Vertigo moulinsiana and V. angustior).