Past pasture management affects the land snail diversity in nutrient-poor calcareous grasslands

Changes in agriculture (intensification or abandonment) have resulted in a dramatical reduction of semi-natural grasslands in Central Europe in the 20th century. Recent management actions aim to restore overgrown and formerly fertilized nutrient-poor grasslands. Former land use is known to influence the present-day vegetation. Similar information is not available for animals with low dispersal ability. We investigated the effect of pasture management history over a period of 55 years on the present-day land snail diversity in 20 dry, nutrient-poor grasslands in the Swiss Jura mountains. Snails were recorded in pastures left unmanaged for 10-40 years but recently cleared from overgrowing shrubs, in pastures fertilized for 15-25 years but recently managed extensively (no fertilizer), and in pastures which have been extensively managed throughout (= control). Past shrub cover had a negative effect on the total number of snail species and the number of red-listed individuals. Former uses of fertilizer reduced red-listed species and individuals and changed the snail community. Three species (Vitrina pellucida, Helicella itala and Abida secale) were found less frequently in formerly fertilized pastures than in extensive pastures. Our results show that changes in pasture use for a period of 10-40 years caused long-term alterations of the land snail fauna. (c) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved. Schneckenfauna im Nordwestschweizer Jura