Měkkýši přírodní rezervace U Nového hradu a přilehlé zříceniny (Česká republika)

This study deals with the land snails in the U Nového hradu Nature Reserve and the nearby castle ruins. The main goal was to make an inventory of the snail fauna and to determine factors affecting species diversity and snail abundance. Further, species richness and composition of the assemblages in the Nature Reserve and the castle ruins were analysed and compared. Snails were collected in summer 2015 by hand picking and litter sampling at 14 quadrats; 10 in the Nature Reserve and four in the castle ruins. In each quadrat plant cover, amount of coarse trees and stones were recorded. Soil pH and conductivity values were measured at each plot. In total, 50 species and 675 individuals of snails were found in all quadrats combined. In the Nature Reserve, 43 species and 406 individuals were recorded. In the castle ruins, there were 33 species and 264 individuals found. On average, higher number of species and individuals per plot were found in the castle ruins than in the reserve. Soil pH was the only variable significantly and positive correlating with the number of snail species recorded. This variable also predicted higher local species richness in the castle ruins than that of the reserve. Based on MDS ordination there was no clear segregation of snail assemblages recorded in the reserve and the castle ruins, though sites from the ruins were more similar to each other that those from the reserve