Due to human pressures, ecosystems are being rapidly modified and habitats fragmented, species are becoming extinct and gene pools are being narrowed - and all this at an increasing and historically unprecedented rate. In a previous project we used a field experiment where we fragmented calcareous grassland into patches of different size over a period of 7 years. The experimental design (block design, 4 fragments and 4 control patches in each block, 12 blocks distributed over 3 sites (Nenzlingen, Movelier and Vicques in the Swiss Jura mountains) circumvented confounding factors such as differences in shape, age and degree of isolation of fragments. In this follow up project we want to use data collected with pitfall traps in the final year of the former project to simultaneously evaluate the influence of habitat fragmentation on species diversity of several invertebrate groups and compare these long-term results to findings made early on in the original project. Data was collected throughout the active season allowing to also examine temporal variation.