Richness of land snail species under isolated stones in a karst area on Öland, Sweden

Species richness of land snails living under isolated stones on an exposed rock surface on the Baltic island of Öland, Sweden, was examined in relation to stone size, microhabitat diversity and isolation. Twelve species were collected under 65 stones of different size. A further five species were found in the surrounding grassland. Surface area of the stone was the most important variable for snail species richness explaining 68.3% of its variation. Microhabitat diversity accounted for further 4.8% of the variation and distance to the nearest stone for 1.9%.