Slakken in de ENCI-kalksteengroeve bij Maastricht

The ENCI cement industry created a large limestone quarry in Sint-Pietersberg hill, just south of Maastricht, province of Limburg. Rehabilitation of the quarry included creation of a south-exposed slope covered by grinded limestone. Seven years later the mollusc fauna of that slope was investigated. Thirteen species were found with marked numerical dominance of Candidula intersecta and Helicella itala. A comparable phenomenon had been observed in 1984, five years after rehabilitation of a different part of the same quarry, currently called ‘ENCI-weide’. Succession in the malacofauna of the ENCI-weide showed 10 species in 1984, 18 species in 1996 and 20 species in 2005 including some species typical for calcareous grasslands. However, in 2020 some of these specific species had decreased in number or were not recovered. In 2020, in total 23 species were observed. Also freshwater molluscs in the ENCI quarry were inventorised and are reported here for the first time. Only six common species were observed, mainly in parts of the quarry where exploitation had finished already decades ago.